Insect of the Week: Leaf miners

Adapted from pages 214-215 in Garden Insects of North America:

Some of the most discriminating feeders among the insects are the leafminers and needleminers . These insects tunnel between the upper and lower leaf surfaces, feeding on the soft inner tissue and avoiding the tough epidermis. Immature stages of many different groups of insects share the leafmining habit, including the larvae of various flies, small moths, beetles, and sawflies. They are often classified by the pattern of the mine they create. Serpentine leaf mines meander across the leaf, gradually increasing in width as the insect grows. More common are various blotch leaf mines, which are an irregular but generally round form.

An adult vegetable leaf miner (Liriomyza sativae) on an onion leaf. Photo credit: Whitney Crenshaw.

One subgroup of these are the tentiform leaf mines, blotchlike mines produced by some types of moth larvae that tie the interior mine with silk in a manner that causes it to pucker (like a tent) as it dries. Many of the fly leafminers in the family Agromyzidae make a serpentine mine as first-instar maggots, but they dramatically enlarge the mine into a blotch when in the second and third instars. These mines are often called comma leaf mines . In addition, small pinholes are usually present that result from feeding wounds by adult female agromyzid flies. These are produced when the female uses her ovipositor to mash underlying cells to release plant juices on which she will feed. As leaves expand, the pinhole wounds can expand into larger shotholes.

To get a glimpse of these mines, head to our Instagram.

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
This post is part of a series, explore additional posts here<< Insect of the Week: the Cabbage LooperPlants That Kill: White Snakeroot >>