Amazing Arachnids: Fishing Spiders

Adapted from pages 296-297 of Amazing Arachnids:

Resting its front feet on the water’s surface, a Dolomedes fishing spider waits along the edge of a small, slow-moving stream. It reads every disturbance, however subtle, on the water’s surface much the way that an orb weaver spider reads the vibrations within its web. In addition to detecting motion with its feet (specifically with the metatarsal lyriform organ), it can also see quite well; its large eyes are not very different from those of its cousin the wolf spider. The fishing spider’s patience is rewarded when an immature grasshopper attempts to leap across the stream and falls onto the surface of the water. Faster than the eye can follow, the fishing spider gallops across the water’s surface and grasps the hapless grasshopper between its two impressive fangs. The spider then returns to the edge of the stream to eat the grasshopper on land, where it efficiently masticates its food and sucks down the liquefied portion until all that is left of the grasshopper is an unrecognizable crumb and a few fragments. 

Dolomedes belongs to the family Pisauridae, also known as nursery web spiders and fishing spiders. In some ways, the fishing spider is the aquatic analogue to the terrestrial wolf spider. This family includes characteristically large, handsome spiders with good eyesight that depend on their speed and strength in order to capture prey. Many of the family frequent moist habitats, but it is the genus Dolomedes that has mastered a lifestyle connected to the water. Despite the fact that some of the species in this genus reach an impressive size (Dolomedes okefenokensis has a leg span of 4 to 5 inches, or 10 to 12.7 cm), they can “row” or even rest their bodies on the water’s surface without breaking the surface tension. The water simply indents or dimples where their legs and body contact the surface. While the spider is on the surface of the water, it

An impressive predator, this mature female Tinus peregrinus fishing spider has captured a fish as large as herself.
She has carried it up into vegetation, where she will masticate and predigest the fish. She must feed out of water or the enzymes needed for predigestion will be diluted out.

is vulnerable to attack from below by underwater predators such as frogs. In this situation, the spider literally levitates by rapidly pushing all its legs downward against the water’s surface to generate the force needed to jump straight up. It then gallops to safety. If the fishing spider becomes startled or frightened by a bird or a wasp, it scrambles underwater, clinging to vegetation so it doesn’t pop back up to the surface. A thin layer of air clings to the hydrophobic cuticle and hairs on the spider’s body, giving it a lovely silvery appearance. It can remain underwater for a good 40 minutes while waiting for the danger to pass. 

Dolomedes spiders must remain vigilant while hunting, because they themselves are hunted. A spider wasp in the pompilid family, Anoplius depressipes, preys exclusively on female Dolomedes spiders. If a fishing spider sees one of these wasps nearby, it takes evasive action, fleeing from the wasp and diving under water in an attempt to escape. But the wasp does something really extraordinary. It actually dives and then swims underwater in pursuit of the unfortunate spider. Once it finds its prey, the wasp stings and paralyzes the spider. The wasp then surfaces with the paralyzed spider and drags it across the water as it skims across in a low flight trajectory. The spider is installed in the nest burrow of the wasp, and a single egg is laid on it. The wasp larva feeds on the still-living, paralyzed Dolomedes until it finally kills the spider. Then the wasp larva pupates.

Unlike the wasp, Dolomedes hunts on the surface of the water. Some authors have written that it hunts underwater, but this has yet to be clearly documented. Instead, it captures its prey primarily either at the surface of the water or on land. Despite this limitation, it can readily catch fish as they swim very close to the water’s surface. The fangs and venom appear to be highly effective in killing the captured fish almost instantly, making it easier for the spider to carry its prey across the water and onto land or up into vegetation growing at the edge of the water. Because spiders ingest only liquefied, predigested food, the fishing spider must eat its prey above the water or else its digestive fluids will be diluted or lost.

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Amazing Arachnids: Pirate Spiders

Adapted from pages 285 to 286 of Amazing Arachnids:

With infinite patience, the pirate spider Mimetus slips into the web of an orb weaver and approaches its prey. Its progress is almost imperceptible as it pauses for long minutes between each stealthy step. But eventually the pirate spider is within striking distance of its quarry. With a sudden lunge, Mimetus attacks the target, using its long chelicerae to administer the lethal bite. Immediately, it releases the victim and waits a bit, making sure that the spider victim is dead. It does not have long to wait; the orb weaver dies almost instantly from the potent venom,  which is highly effective against spiders. The pirate spider then settles down to suck out the contents of the orb weaver, leaving the cuticle of its prey almost completely intact. The web built by the orb weaver to capture food is now the platform for its own consumption.

Slow and stealthy, pirate spiders hardly seem like lethal predators at first glance. But pirate spiders have made a specialty of hunting other spiders, especially the orb weavers and the combfooted spiders (the theridiids), including even black widows. The spiders in the family Mimetidae possess extremely long front legs armed with heavy, slightly curved setae. Another spider hunter, Rhomphaea, also has exceptionally long front legs. Perhaps this is a useful adaptation when attacking a spider in its web, giving the attacker a superior reach.

Pirate spider

A Metapeira met a pirate. Incredibly slow and stealthy, the female pirate spider Mimetus hesperus slipped into the web of a small Metapeira orb weaver, taking more than an hour before getting close enough for the final lethal attack. The pirate spider then fed at her leisure.

The name Mimetidae is based on the Greek word for “imitator, actor, and impersonator.” In fact, the genus Eros is notorious for incorporating deception into its hunting repertoire, utilizing what is called aggressive mimicry. Aggressive mimicry is defined by a predator (the mimic) imitating a harmless organism (the model), thereby attracting the prey. Aggressive mimics that target more than one species of prey may have evolved highly complex repertoires of behaviors, and may demonstrate plasticity in the use of these behaviors. Staying near the periphery of the victim’s web, Eros seductively plucks the silk, imitating a courting male. When the resident spider hurries over to investigate, Eros bites her on the leg and kills her. Eros then eats not only the spider, but any eggs as well. In 1850, Nicholas Marcellus Hentz wrote, “The Mimetus … prefers prowling in the dark, and taking possession of the industrious Epeira’s threads and home, or the patient Theridion’s web, after murdering the unsuspecting proprietor.” Occasionally, though, if Mimetus becomes a little careless, the hunter may become the hunted, and the pirate spider may be killed by the resident spider and then eaten.

Although the female Mimetus seems to prefer spiders as the predominant prey, male Mimetus readily hunt other small arthropods such as gnats. The males may be seen as regular visitors on sliding glass doors at night, feeding on small gnats attracted to the light. It is sometimes difficult to imagine that this innocuous male belongs to the same species as the lethal female.

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

 

Amazing Arachnids: Tarantulas

Adapted from pages 165-172 of Amazing Arachnids:

Tarantulas range in size from the largest spider in the world, Theraphosa blondi of South America, with a leg span of up to about 10 inches (25 cm), to Aphonopelma paloma, with a leg span of only 0.75 inches (2 cm).

Tarantulas also have a variety of lifestyles and behaviors, from the stereotypically solitary burrow dweller to the subsocial behavior of some communal species, such as the dwarf tarantula species Holothele (from South America) and Heterothele (from Africa). These communal spiders may cooperatively kill prey and young spiders share the kill. Circumstantial evidence suggests that even some species that live in underground burrows may have extended maternal care of young. In a number of instances, young tarantulas well beyond the third instar have been found  sharing an adult female’s burrow, leading to speculation regarding whether the mother shares food with her offspring.

Tarantula

Aphonopelma chalcodes adult male. These large males have a leg span of about 4 inches (10 cm) and are a common sight as they wander during the summer monsoon season (July and August) in southern Arizona.

The tarantulas of the southwestern United States belong to the genus Aphonopelma. These range in size from fairly large species such as Aphonopelma chalcodes, with a leg span of about 4 to 5 inches (10– 12.7 cm), to the tiny Aphonopelma paloma. A number of Aphonopelma are intermediate in size and are restricted to the mountains of southern Arizona. These tarantulas have a leg span of only about 2 inches (5 cm). The males mature in late fall or winter and may be seen as they wander in search of females even when there is snow on the ground. Because these mountain ranges are separated by barriers of low desert, many of the “sky island” populations have been geographically separated long enough that they are separate species.

One of the most common and conspicuous species is Aphonopelma chalcodes, also known as the desert blond tarantula. This handsome spider lives in an underground burrow in the low-elevation deserts of Arizona and may take about 10 years to reach maturity. The male looks markedly thinner and leggier than the female and, in addition, acquires a tibial spur on his front legs with his final molt. The males leave their burrows upon reaching maturity and go wandering in search of females. They are a familiar sight in the southern Arizona desert during the summer monsoon season, cruising at night or during the late afternoon, especially after a summer rain storm.

Hollywood has effectively exploited these fears, conjuring up giant tarantulas, deadly venomous tarantulas, and tarantulas that wipe out entire towns. But these animals have so much more to offer than cheap thrills. Their beauty and their diversity in both appearance and lifestyle defy the imagination and far surpass Hollywood’s wildest dreams. Certainly, they compel our respect, as does any predator capable of self-defense, but they also deserve our appreciation and protection.

We included a photo of one of the largest tarantulas – but what about the smallest? Head to our Instagram to see how tiny tarantulas can be. 

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Amazing Arachnids: Orb Weavers

Adapted from pages 184-186 of Amazing Arachnids:

A delight to the eye and an engineering marvel, the orb web epitomizes the stereotypical spider web. It is built in a vertical plane, with strong, nonsticky silk radiating out from a central hub like the spokes of a wheel, supporting a spiral of evenly spaced sticky silk threads. A gap in the sticky silk near the hub allows the orb weaver to rapidly climb from one side of the web to the other, depending on which side of the web a flying insect has blundered into. Some orb weavers wait in the center of the web, legs stretched out in contact with the radiating silk lines that convey the vibrations of a struggling insect. Others build a little retreat at one side of the web, maintaining contact with the radiating lines via a signal thread leading to the hub. Lying in wait in the retreat, the spider rests with one leg touching the signal line. At the first indication that an insect has been caught, the spider moves into the web and tugs at the radial lines, testing to see the general location of the prey. It then uses the nonsticky radial lines as a quick pathway leading to the insect. Once the prey is reached, the spider uses large amounts of silk to wrap and immobilize it prior to settling in for the meal.

Many orb weavers build a fresh web every night and eat the silk by the next morning. Experiments with radioactive labeling have shown that spiders are the ultimate recyclers; up to 90 percent of the old silk is recycled into the new web, and such ingestion and reuse of the silk protein can occur in as little as 30 minutes. The spiral silk of the orb weavers owes its stickiness to the addition of little beads of viscous glue along its length, like the beads of a necklace. Neither the radial threads nor the hub threads have this glue, allowing the spider easy and rapid access to all parts of its web.

An orb weaver spider

Surreal in color and form, the spiny orb weaver, Gasteracantha cancriformis, builds its web in trees and other tall
vegetation. This genus occurs primarily in the tropics; however, this particular species is also found across the
southernmost states in North America.

Some orb weavers build a web that remains in place for more than one day. Among these diurnal spiders are some that incorporate a special structure into the web, called the stabilamentum. The stabilamentum is composed of a thicker kind of silk, frequently appearing as a conspicuous white area in the web. It may look like a lace doily, or like one or more heavy zigzags in the web. Another type of stabilamentum consists of a line of silk above and below the resting spot in the hub of the web. The empty husks of insect prey are attached to this line, forming irregular clumps of detritus. Sitting motionless in the open spot in the middle of this detritus, the orb weaver Cyclosa appears to be just one more clump of debris in the stabilamentum. Camouflage protects the spider against predation by birds. Yet a different type of protection from birds may be derived from the presence of stabilamenta.

Orb weavers are more flexible in their ability to react to different circumstances than one might imagine. They build larger webs when they are hungry or if they are in areas of low prey availability than when they are well fed or in areas of high prey availability. Both web design and the timing of its construction are synchronized with the type of prey and its availability, requiring the adjustment of the spider’s circadian rhythm. In addition, orb weavers modify their approach to different types of prey in the web depending on whether the prey is potentially dangerous or not. They seem to know what kind of prey has been captured (perhaps based on the vibrations transmitted from its struggles) even before the spider physically makes contact with the prey. Some undesirable prey, such as stinging insects, are deliberately cut loose and released from the web. Other prey, like stink bugs, may be carefully wrapped so as to avoid eliciting a release of defensive chemicals until the killing bite can be administered in safety.

Amazing Arachnids coverAmazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Amazing Arachnids: Vinegaroons

Adapted from pages 69-74 of Amazing Arachnids:

Armed with heavy, lobsterlike claws at the front end of their bodies and shooting almost pure acetic acid out of their rear ends, vinegaroons seem to have stepped straight out of a science fiction novel. Despite their fantastic abilities, vinegaroons are perhaps the most poorly understood of the large arachnids. This may be the result of their nocturnal habits, dark nonfluorescent coloration, and the fact that they live most of their lives underground. However, the story of these enigmatic creatures is well worth the cost, albeit paid for in sleepless nights. Their story rivals and even surpasses the creations of fiction.

The common name “vinegaroon” is well chosen. The defensive spray of the vinegaroon Mastigoproctus giganteus of the southwestern United States consists primarily of acetic acid (up to 84 percent), water (10 percent), and caprylic acid (5 percent). Acetic acid is, of course, the component that gives vinegar its characteristic odor. Hydrophilic “water-loving” acetic acid in pure form simply beads up on the lipid-containing cuticle of most arthropods. But with the addition of the lipophilic “lipid-loving” caprylic acid, the spray spreads easily and penetrates into the cuticle. The caprylic acid derives its surfactant properties from a chain of 8 carbon atoms in the molecule, as compared with only 2 carbons contained in acetic acid. The acetic acid spray is produced in a pair of pygidial glands in the abdomen of the vinegaroon. Contraction of muscles in the outer layer surrounding the gland discharges the mixture as a spray from a knoblike structure called the pygidium at the base of the “tail” (called the flagellum). By bending the abdomen and rotating the knob, the vinegaroon can direct the spray with considerable accuracy, even if the target is almost directly in front of it.

As added protection, vinegaroons can defend themselves by spraying almost pure acetic acid from the pygidium, located at the base of the flagellum. By rotating the pygidium, the vinegaroon can aim the spray in almost any direction, even almost immediately in front of it. The flagellum assists the vinegaroon in accurately aiming the spray. Photo by Bruce D. Taubert.

Vinegaroons may spray repeatedly (as many as 19 times) before depleting their reserve of defensive chemicals. It takes about a day for them to recharge their reservoir. The spray has proven to serve as a deterrent to the most formidable arthropod foes such as ants. It also repels vertebrate predators such as the fierce little predaceous grasshopper mice. In contact with human skin, it may cause a burning sensation, and of course the eyes of a potential vertebrate predator such as a bird or a grasshopper mouse would be highly vulnerable to the effects of the acid.

The acetic acid is used purely as a defense weapon—not for capturing prey. A hunting vinegaroon employs tools similar to those used by scorpions for  detecting prey. A combination of sensilla (to pick up substrate vibrations) and trichobothria (to detect airborne vibrations) on the uropygid’s legs allow it to narrow down the general location of its quarry. The tiny hairs on the flagellum might also assist in this task. At the same time, the antenniform legs are extended forward, tapping the surface as the uropygid seeks out prey. Chemosensory hairs on the antenniform legs provide chemical clues as to the identity of any objects it encounters. As soon as the vinegaroon has positively identified a potential prey animal, it charges forward, grabbing with its heavy, clawlike palps. If it misses with the first try, it excitedly feels around with the antenniform legs, searching until it has once again located its quarry.

There are 4 free living instar stages before maturation, and since the young uropygid may not molt following a poor year, it may take from 5 to 7 years to reach maturity. Vinegaroons do not molt again once they are mature, and so their normal lifespan in the wild is probably in the range of 6 to 9 years. Eventually, this magnificent predator slows down due to old age, as joints stiffen and lost appendages cannot be regenerated. Perhaps even in the wild, it may actually die of old age, still a formidable predator to the end.

 

Amazing Arachnids
By Jillian Cowles

The American Southwest is home to an extraordinary diversity of arachnids, from spitting spiders that squirt silk over their prey to scorpions that court one another with kissing and dancing. Amazing Arachnids presents these enigmatic creatures as you have never seen them before. Featuring a wealth of color photos of more than 300 different kinds of arachnids from eleven taxonomic orders–both rare and common species—this stunningly illustrated book reveals the secret lives of arachnids in breathtaking detail, including never-before-seen images of their underground behavior.

Amazing Arachnids covers all aspects of arachnid biology, such as anatomy, sociality, mimicry, camouflage, and venoms. You will meet bolas spiders that lure their victims with fake moth pheromones, fishing spiders that woo their mates with silk-wrapped gifts, chivalrous cellar spiders, tiny mites, and massive tarantulas, as well as many others. Along the way, you will learn why arachnids are living fossils in some respects and nimble opportunists in others, and how natural selection has perfected their sensory structures, defense mechanisms, reproductive strategies, and hunting methods.

  • Covers more than 300 different kinds of arachnids, including ones new to science
  • Features more than 750 stunning color photos
  • Describes every aspect of arachnid biology, from physiology to biogeography
  • Illustrates courtship and mating, birth, maternal care, hunting, and defense
  • Includes first-ever photos of the underground lives of schizomids and vinegaroons
  • Provides the first organized guide to macroscopic mites, including photos of living mites for easy reference

Insect of the Week: Synchronous Symphonies

Among all the glamorous mating rituals that have been shaped by evolution, the displays performed by certain synchronously flashing fireflies might rank as the most spectacular. For reasons we don’t yet understand, only a few lightningbugs show a remarkable behavior: thousands of male fireflies will match up their rhythms to flash together in unison. Two distinct types of synchronous flash behavior have been observed: one type involves stationary males, while the other takes place among roving (flying) fireflies.

In southeast Asia, certain Pteroptyxmale fireflies sit in communal display trees along tidal rivers, where each night they spend hours flashing together in perfect synchrony. Females fly to these stationary aggregations, known as leks, where mating occurs.

Writing in the journal Science in 1935, Hugh Smith, a naturalist living in Thailand, described these dazzling displays:

Photo credit: Radim Schreiber

Imagine a tree thirty-five to forty feet high thickly covered with small ovate leaves, apparently with a firefly on every leaf and all the fireflies flashing in perfect unison at the rate of about three times in two seconds, the tree being in complete darkness between the flashes. Imagine a dozen such trees standing close together along the river’s edge with synchronously flashing fireflies on every leaf. Imagine a tenth of a mile of riverfront with an unbroken line of Sonneratia[mangrove] trees with fireflies on every leaf flashing in synchronism, the insects on the trees at the ends of the line acting in perfect unison with those between.

 

Because fireflies congregrate so predictably in the same trees, night after night for months, native boatmen once navigated among the twisting waterways using firefly display trees as landmarks.

But stationary flash synchrony doesn’t happen in any North American fireflies. Instead, several of our lightningbug species show a kind of wave synchrony, where flashes are synchronized locally among males flying within line-of-sight of each other. In the southern Appalachians, the synchronous symphony of Photinus carolinusattracts thousands of visitors to admire these flying males as they coordinate their six-pulsed courtship flashes with those of nearby males. These fireflies create waves of synchronous flashing that moves through the forest in the Allegheny National Forest and Great Smoky Mountains National Park. Similar displays of wave synchrony among roving males can be seen in mating displays of Photuris frontalis in Congaree National Park, South Carolina, Photinus knulli in Arizona, and Macrolampis palaciosi in Tlaxcala, Mexico. When they’re in a dense population, males of other fireflies will sometimes synchronize their flashes for a short time.

Wherever you find them, synchronous fireflies make an indelible impression – they are certainly one of Earth’s great natural treasures!

 

Learn more about firefly synchrony in Silent Sparks: The Wondrous World of Fireflies, and on the author’s firefly blog.

silent sparksSilent Sparks
The Wondrous World of Fireflies

For centuries, the beauty of fireflies has evoked wonder and delight. Yet for most of us, fireflies remain shrouded in mystery: How do fireflies make their light? What are they saying with their flashing? And what do fireflies look for in a mate? In Silent Sparks, noted biologist and firefly expert Sara Lewis dives into the fascinating world of fireflies and reveals the most up-to-date discoveries about these beloved insects. From the meadows of New England and the hills of the Great Smoky Mountains, to the rivers of Japan and mangrove forests of Malaysia, this beautifully illustrated and accessible book uncovers the remarkable, dramatic stories of birth, courtship, romance, sex, deceit, poison, and death among fireflies.

The nearly two thousand species of fireflies worldwide have evolved in different ways—and while most mate through the aerial language of blinking lights, not all do. Lewis introduces us to fireflies that don’t light up at all, relying on wind-borne perfumes to find mates, and we encounter glow-worm fireflies, whose plump, wingless females never fly. We go behind the scenes to meet inquisitive scientists who have dedicated their lives to understanding fireflies, and we learn about various modern threats including light pollution and habitat destruction. In the last section of the book, Lewis provides a field guide for North American fireflies, enabling us to identify them in our own backyards and neighborhoods. This concise, handy guide includes distinguishing features, habits, and range maps for the most commonly encountered fireflies, as well as a gear list.

A passionate exploration of one of the world’s most charismatic and admired insects, Silent Sparks will inspire us to reconnect with the natural world.

Insect of the Week: How to Make Your Yard More Firefly-Friendly

silent sparksYour neighborhood might have hundreds of fireflies, or maybe you have just a few. Perhaps you have none at all. No matter which, here are some simple things that will help make any yard more attractive to local fireflies.

Create an inviting habitat:
Fireflies need moisture during all of their life stages (that is, eggs, larvae, pupae and the adult).

  • Let the grass grow longer in parts of your lawn to help the soil hold more moisture.
  • Juvenile fireflies spend up to two years living underground, where they feed on earthworms and snails. If you leave some leaf litter and woody debris in the corners of your yard, this will help larval fireflies—and their prey—to thrive.
  • Female fireflies lay their eggs in moist, mossy places, so preserve any wetlands, streams, or ponds in your neighborhood.

Bring back the night:
Fireflies court using bioluminenscent flashes, so artificial lights that are too bright can interfere with their ability to find mates.

  • When installing or re-thinking your outdoor lighting, use only what you need to get the job done.
  • Use shielded lighting fixtures recommended by the International Dark-Sky Association; these direct light downward, where it’s most useful. Use bulbs as low-wattage as possible to provide just the light you need for safety and security.
  • Try turning off your outdoorlights, or put them on timers, particularly during firefly season.

Reduce pesticide use:
Because juveniles fireflies spend months living underground, they will come into contact with any insecticides spread on lawns and gardens. Broad-spectrum insecticides like malathion and diazinon will kill whatever insects they contact, including fireflies.

  • Consider using organic or least-toxic practices and products on your lawn and garden. Avoid broad-spectrum insecticides – use horticultural oils or insecticidal bacteria like Bt designed to target specific pests.
  • Apply pesticides to treat specific pest problems, never routinely.
  • Don’t use Weed & Feed or similar products that contain 2,4-D, which has been shown to be toxic to earthworms and beetles like ladybugs.

As I describe in Silent Sparks, our scientific understanding of firefly biology and habitat requirements has grown exponentially over the past few decades. Such knowledge now provides a powerful tool for protecting fireflies. And of course, we can all work to preserve and restore the wild places where fireflies thrive – their fields and forests, their mangoves and meadows. We all dream about the kind of world we want our children to inherit. Let’s make certain the magical sparkle of fireflies will continue to be part of their world.

Silent Sparks
The Wondrous World of Fireflies

For centuries, the beauty of fireflies has evoked wonder and delight. Yet for most of us, fireflies remain shrouded in mystery: How do fireflies make their light? What are they saying with their flashing? And what do fireflies look for in a mate? In Silent Sparks, noted biologist and firefly expert Sara Lewis dives into the fascinating world of fireflies and reveals the most up-to-date discoveries about these beloved insects. From the meadows of New England and the hills of the Great Smoky Mountains, to the rivers of Japan and mangrove forests of Malaysia, this beautifully illustrated and accessible book uncovers the remarkable, dramatic stories of birth, courtship, romance, sex, deceit, poison, and death among fireflies.

The nearly two thousand species of fireflies worldwide have evolved in different ways—and while most mate through the aerial language of blinking lights, not all do. Lewis introduces us to fireflies that don’t light up at all, relying on wind-borne perfumes to find mates, and we encounter glow-worm fireflies, whose plump, wingless females never fly. We go behind the scenes to meet inquisitive scientists who have dedicated their lives to understanding fireflies, and we learn about various modern threats including light pollution and habitat destruction. In the last section of the book, Lewis provides a field guide for North American fireflies, enabling us to identify them in our own backyards and neighborhoods. This concise, handy guide includes distinguishing features, habits, and range maps for the most commonly encountered fireflies, as well as a gear list.

A passionate exploration of one of the world’s most charismatic and admired insects, Silent Sparks will inspire us to reconnect with the natural world.

Insect of the Week: Skipper Butterflies

Adapted from page 55-58 of Butterfly Gardening:

Skippers are small, fast-flying butterflies that many people initially think are moths. Skippers have relatively thick bodies and short wings and their flight is often characterized as fast, darting, or jerky—obviously thought by some to be a “skipping” motion.

The vast majority of the skippers in the United States lack colorful scales and so tend to be orange, white, brown, black, or gray. Many skippers are smaller than the familiar and colorful garden visitors that initially come to mind when thinking “butterfly,” but once you notice skippers, you will appreciate the motion and activity they add to the garden.

A Common-Checkered Skipper in a typical spread-wing stance. Photo credit: Alan Schmierer.

Two subfamilies of skippers visit gardens in the United States: spreadwing skippers and grass-skippers. The spreadwing skippers generally perch with both forewings and hindwings open flat, while grass-skippers sit perkily with all wings closed or with the forewings open at a 45-degree angle to the flat hindwings. It is possible to get a peek at the open wings of a grass-skipper when it basks in the sun, a common behavior. Grass-skippers are also equipped with exceedingly long tongues, allowing them to nectar at many types of flowers.

Common Checkered-Skipper is likely the most widespread skipper in the United States, and its caterpillars feed on plants in the Mallow Family. This spreadwing skipper inhabits many different settings, from prairies and meadows to yards and pastures. Open, sunny, often disturbed places are what Common Checkered-Skippers prefer.

Butterfly Gardening: The North American Butterfly Association Guide
By Jane Hurwitz

Butterfly gardening creates habitats that support butterflies, connecting us with some of the most beautiful creatures in the natural world and bringing new levels of excitement and joy to gardening. In this engaging and accessible guide, lavishly illustrated with more than two hundred color photographs and maps, accomplished butterfly gardener Jane Hurwitz presents essential information on how to choose and cultivate plants that will attract a range of butterflies to your garden and help sustain all the stages of their life cycles.

An indispensable resource for aspiring and experienced butterfly gardeners alike, Butterfly Gardening is the most gardener-friendly source on the subject, covering all the practical details needed to create a vibrant garden habitat that fosters butterflies. It tells you which plants support which butterflies, depending on where you live; it describes what different butterflies require in the garden over the course of their lives; and it shows you how to become a butterfly watcher as well as a butterfly gardener.

While predominantly recommending regionally native plants, the book includes information on non-native plants. It also features informative interviews with experienced butterfly gardeners from across the United States. These gardeners share a wealth of information on plants and practices to draw butterflies to all kinds of gardens–from small suburban gardens to community plots and larger expanses.

Whether you are a gardener who wants to see more butterflies in your garden, a butterfly enthusiast who wants to bring that passion to the garden, or someone who simply wants to make their garden or yard friendlier to Monarchs or other butterflies, this is a must-have guide.

  • An essential guide for aspiring and experienced butterfly gardeners
  • Encourages readers to rethink gardening choices to support butterflies and other pollinators in their gardens and communities
  • Introduces gardeners to butterfly watching
  • Includes regional lists of plant species that are time-proven to help sustain butterflies and their caterpillars
  • Features informative interviews with expert butterfly gardeners from across the United States

 

Insect of the Week: the Great Spangled Fritillary

Adapted from pages 85 to 87 of Butterfly Gardening:

The Great Spangled Fritillary is a large, showy butterfly found throughout a large section of the United States from southern Canada down to northern California on the western half of the continent, with the range extending down across the country to North Carolina on the East Coast. Within its range, the Great Spangled Fritillary can be considered a common garden butterfly that is on the wing during the summer months and through the early fall.

Violets are the only plant that Great Spangled Fritillary caterpillars will eat. Great Spangled Fritillaries do not care whether the violet flowers are blue, yellow, or white, though it does matter to egg-laying butterflies that the violets are native. African “violets,” which are grown as houseplants, and pansies, which are sold at garden centers as outdoor bedding plants, are not suitable for Great Spangled Fritillary caterpillars. Since most violets spread enthusiastically, you may regard them as weeds or wildflowers, but native violets are the kind needed to feed Great Spangled Fritillaries as well as a number of other fritillary species that have smaller ranges.

A Great Sprangled Fritillary laying eggs near a violet. Photo credit: Jane Hurwitz

Butterflies bearing the common name “fritillary” can be confusing; since they all share a name, one could conclude that they all belong to the same genus, and therefore share similar characteristics. But things are not that tidy in the butterfly world, or in the gardening world either, and the fritillaries mentioned so far are actually all a bit different.

Great Spangled Fritillary belongs to the genus Speyeria. They have one brood per year and their caterpillars eat only violets. Hosting Great Spangled Fritillaries requires gardeners to hold off on vigorous flowerbed cleaning in the fall. By leaving leaf litter undisturbed surrounding violets, gardeners preserve caterpillar overwintering habitat, ensuring that any unseen caterpillars are able to remain near violets and complete their life cycle. Since Great Spangled Fritillary produces only one generation per year, if your yard is cleared each fall and spring by landscape crews, or by overenthusiastic family members sent outside on a fine fall day, the potential to lose overwintering caterpillars is high.

 

Butterfly Gardening: The North American Butterfly Association Guide
By Jane Hurwitz

Butterfly gardening creates habitats that support butterflies, connecting us with some of the most beautiful creatures in the natural world and bringing new levels of excitement and joy to gardening. In this engaging and accessible guide, lavishly illustrated with more than two hundred color photographs and maps, accomplished butterfly gardener Jane Hurwitz presents essential information on how to choose and cultivate plants that will attract a range of butterflies to your garden and help sustain all the stages of their life cycles.

An indispensable resource for aspiring and experienced butterfly gardeners alike, Butterfly Gardening is the most gardener-friendly source on the subject, covering all the practical details needed to create a vibrant garden habitat that fosters butterflies. It tells you which plants support which butterflies, depending on where you live; it describes what different butterflies require in the garden over the course of their lives; and it shows you how to become a butterfly watcher as well as a butterfly gardener.

While predominantly recommending regionally native plants, the book includes information on non-native plants. It also features informative interviews with experienced butterfly gardeners from across the United States. These gardeners share a wealth of information on plants and practices to draw butterflies to all kinds of gardens–from small suburban gardens to community plots and larger expanses.

Whether you are a gardener who wants to see more butterflies in your garden, a butterfly enthusiast who wants to bring that passion to the garden, or someone who simply wants to make their garden or yard friendlier to Monarchs or other butterflies, this is a must-have guide.

  • An essential guide for aspiring and experienced butterfly gardeners
  • Encourages readers to rethink gardening choices to support butterflies and other pollinators in their gardens and communities
  • Introduces gardeners to butterfly watching
  • Includes regional lists of plant species that are time-proven to help sustain butterflies and their caterpillars
  • Features informative interviews with expert butterfly gardeners from across the United States

 

Insect of the Week: the May/June beetle

Adapted from pages 466-468 of Garden Insects of North America:

May/June Beetles (Phyllophaga spp.) are among the largest of the white grubs, typically about 3/4 inches to 1 inch long and stout-bodied. Adults are generally chocolate brown to nearly black. More than 200 species occur in North America, with about 25 reported to damage turfgrasses, garden plants, and field crops. The adults are active at night and may be seen careening around porch lights and bouncing off screens, often in late spring. The beetles feed on the foliage of various trees and shrubs, with oak a preferred host for many species, but this rarely results in any significant injuries. Much more significant damage results from the white grub larvae, which chew on plant roots. Grasses are most commonly damaged, but larvae can seriously injure roots of young trees and shrubs planted in grassy areas.

 In northern areas, May/June beetles often have an extended life cycle that requires 3 years to complete. With these species, eggs are laid in the soil in May or June, and a limited amount of feeding takes place by young larvae during the first season, before they migrate downward for winter. They return to feed on roots and grow rapidly during the second season, producing most damage at this time. In the third year there is some additional feeding before the insects pupate in a belowground chamber. They transform to adults in late summer and early fall, ready to emerge the following year.

An adult May/June beetle. Photo credit: David Shetlar

Variations of May/June beetle life cycles occur, and in the southern U.S. many species complete development in a single season. Phyllophaga crinita, an important species in Texas, and P. latifrons, found in most Gulf States, have this habit. They commonly damage St. Augustinegrass, bermudagrass, and buffalograss.

Garden Insects of North America: The Ultimate Guide to Backyard Bugs
Second Edition
By Whitney Cranshaw & David Shetlar

This second edition of Garden Insects of North America solidifies its place as the most comprehensive guide to the common insects, mites, and other “bugs” found in the backyards and gardens of the United States and Canada. Featuring 3,300 full-color photos and concise, detailed text, this fully revised book covers the hundreds of species of insects and mites associated with fruits and vegetables, shade trees and shrubs, flowers and ornamental plants, and turfgrass—from aphids and bumble bees to leafhoppers and mealybugs to woollybears and yellowjacket wasps—and much more. This new edition also provides a greatly expanded treatment of common pollinators and flower visitors, the natural enemies of garden pests, and the earthworms, insects, and other arthropods that help with decomposing plant matter in the garden.

Designed to help you easily identify what you find in the garden, the book is organized by where insects are most likely to be seen—on leaves, shoots, flowers, roots, or soil. Photos are included throughout the book, next to detailed descriptions of the insects and their associated plants.

An indispensable guide to the natural microcosm in our backyards, Garden Insects of North America continues to be the definitive resource for amateur gardeners, insect lovers, and professional entomologists.

  • Revised and expanded edition covers most of the insects, mites, and other “bugs” one may find in yards or gardens in the United States and Canada—all in one handy volume
  • Features more than 3,300 full-color photos, more than twice the illustrations of the first edition
  • Concise, informative text organized to help you easily identify insects and the plant injuries that they may cause

 

Insect of the Week: the Emerald Ash Borer

Adapted from pages 434-435 of Garden Insects of North America

The larvae of the emerald ash borer develop under the bark of trees, creating zigzag tunnels through the cambium. Cumulative injuries cause a progressive dieback that initially involves upper limbs but ultimately moves into the trunks. Typically trees are killed within 5 years after they are first colonized.

The first North American detection of emerald ash borer was in 2002 in Detroit. By 2016 this insect was found in most states east of the Mississippi, two Canadian provinces, and two western states (Colorado, Texas). The rapid spread of this insect over wide areas has been largely through the human-assisted movement of infested ash firewood. Once introduced into a location, local dispersal occurs from the flight of adults during late spring and early summer. Adults are metallic green beetles, approximately 1/2 inch long. The larvae are flatheaded borers that make meandering tunnels through the cambium, under the bark. Adults emerge from trees through D-shaped exit holes in the bark.

An emerald ash borer with wings open (Agrilus planipennis).                            Photo credit: David Shetlar.

Winter is spent as a larva within tunnels under the bark and pupation occurs in mid-spring. Adults can be expected to begin to emerge in late May, about the time black locust (Robinia) is in full bloom. Initially they feed on the foliage and, about 2 weeks later, after mating, females begin to lay eggs on the surface of trunks and branches. About 100 eggs may be laid on the trunk or larger limbs, usually at points of rough bark and in cracks of the bark, with most egg laying completed by early July. 

Eggs hatch about 2 weeks after being laid, and the larvae bore into the plant where they feed on the sapwood. As they feed and develop the larvae extend their mines under the bark, the size of the tunnels gradually widening as the insect grows. Fine sawdust frass packs these galleries. Larval feeding continues until the larva is mature or until weather becomes too cold for development. Growth is resumed in spring when they complete their development. Normally, one generation is produced annually. Development may be slowed in more vigorous trees in early stages of infestation and in cooler areas some larvae that develop from eggs laid late in the season have been observed to require a second season to mature.

Garden Insects of North America: The Ultimate Guide to Backyard Bugs
Second Edition
By Whitney Cranshaw & David Shetlar

This second edition of Garden Insects of North America solidifies its place as the most comprehensive guide to the common insects, mites, and other “bugs” found in the backyards and gardens of the United States and Canada. Featuring 3,300 full-color photos and concise, detailed text, this fully revised book covers the hundreds of species of insects and mites associated with fruits and vegetables, shade trees and shrubs, flowers and ornamental plants, and turfgrass—from aphids and bumble bees to leafhoppers and mealybugs to woollybears and yellowjacket wasps—and much more. This new edition also provides a greatly expanded treatment of common pollinators and flower visitors, the natural enemies of garden pests, and the earthworms, insects, and other arthropods that help with decomposing plant matter in the garden.

Designed to help you easily identify what you find in the garden, the book is organized by where insects are most likely to be seen—on leaves, shoots, flowers, roots, or soil. Photos are included throughout the book, next to detailed descriptions of the insects and their associated plants.

An indispensable guide to the natural microcosm in our backyards, Garden Insects of North America continues to be the definitive resource for amateur gardeners, insect lovers, and professional entomologists.

  • Revised and expanded edition covers most of the insects, mites, and other “bugs” one may find in yards or gardens in the United States and Canada—all in one handy volume
  • Features more than 3,300 full-color photos, more than twice the illustrations of the first edition
  • Concise, informative text organized to help you easily identify insects and the plant injuries that they may cause

Insect of the Week: the False chinch bug

Adapted from page 299 of Garden Insects of North America

 False chinch bugs are about 1/6 inch, winged, and slightly more elongate in form than “true” chinch bugs. General coloration is mottled gray, with the thorax and head somewhat darker. Nymphs are gray-brown and have some reddish or orange markings on the abdomen. False chinch bugs are generally distributed throughout most of western North America but are particularly common in the High Plains and Intermountain West. 

False chinch bugs suck the sap from plants during feeding. The adults also commonly aggregate and occur in large numbers on individual plants, causing plants to wilt and die rapidly. Outbreaks are sporadic but can destroy plantings, particularly early in the year. Later in the season, aggregations tend to be greatest on developing seed heads. False chinch bugs are sometimes a nuisance pest of homes and buildings during hot summers when they may migrate into buildings. Most garden plants can be damaged during outbreaks; crucifers and beet family plants are favored. Wild hosts include many weeds such as tansy mustard, kochia, Russian thistle, and sagebrush. 

False chinch bugs (Nysius spp.) at mixed life stages. Photo credit: Whitney Cranshaw

False chinch bugs spend the winter as nymphs or adults under protective debris near winter annual mustards they use for hosts. They become active in early spring and move to developing mustards to feed. Adults lay eggs in loose soil or soil cracks around plants and eggs hatch in about 4 days. Under summer conditions, the wingless, gray nymphs feed for about 3 weeks and then reach the adult stage. Adults live for several weeks, fly readily, and can disperse over wide areas. About three generations are usually produced, with peak numbers often appearing in July and early August.

Garden Insects of North America: The Ultimate Guide to Backyard Bugs
Second Edition
By Whitney Cranshaw & David Shetlar

This second edition of Garden Insects of North America solidifies its place as the most comprehensive guide to the common insects, mites, and other “bugs” found in the backyards and gardens of the United States and Canada. Featuring 3,300 full-color photos and concise, detailed text, this fully revised book covers the hundreds of species of insects and mites associated with fruits and vegetables, shade trees and shrubs, flowers and ornamental plants, and turfgrass—from aphids and bumble bees to leafhoppers and mealybugs to woollybears and yellowjacket wasps—and much more. This new edition also provides a greatly expanded treatment of common pollinators and flower visitors, the natural enemies of garden pests, and the earthworms, insects, and other arthropods that help with decomposing plant matter in the garden.

Designed to help you easily identify what you find in the garden, the book is organized by where insects are most likely to be seen—on leaves, shoots, flowers, roots, or soil. Photos are included throughout the book, next to detailed descriptions of the insects and their associated plants.

An indispensable guide to the natural microcosm in our backyards, Garden Insects of North America continues to be the definitive resource for amateur gardeners, insect lovers, and professional entomologists.

  • Revised and expanded edition covers most of the insects, mites, and other “bugs” one may find in yards or gardens in the United States and Canada—all in one handy volume
  • Features more than 3,300 full-color photos, more than twice the illustrations of the first edition
  • Concise, informative text organized to help you easily identify insects and the plant injuries that they may cause