Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar

John van der Linden, Contributing Editor
Full name:
John van der Linden
Contact:
To reach me, please post a comment on one of my BugGuide posts and I will get back to you.
Biography:

I am a naturalist and citizen scientist with an interest in discovering, documenting, and sharing information about specific associations between plants and insects.

Gallmakers are insects (but also sometimes fungi, mites, and other living things) whose particular relationship with their host plant results in distinctive swellings or other unique growths in which the larvae feed, shelter, and develop. In many cases, details of gall morphology can be used to identify the insect that is or was present. Successful rearing of galls may require precise timing of collection and careful regulation of moisture in the rearing container (not to mention luck!), but it is not always difficult. Galls often host animals other than the gallmaker, including predators, parasitoids, and residents known as inquilines. A large family of insects that includes many gallformers (and in which I am particularly interested) is the Cecidomyiidae, or gall midges. Intriguingly, some plant-feeding cecidomyiids do not form galls, but are hidden away cryptically in "normal-looking" stems, leaves, flowers, and other plant parts, awaiting discovery by a keen eye.

Leaf miners create trails as they feed inside leaves. They are primarily moths, beetles, flies, and sawflies. My colleague Charley Eiseman is spearheading a leafminer renaissance in North America, in part through his effort to create a comprehensive guide to all such mines that may be found on the continent. His self-published eBook is well over a thousand pages long...and counting.

Stem miners travel just beneath the epidermis (outer skin) of an herbaceous plant stem, leaving a visible feeding trail. Sometimes the trail is raised, like a molehill winding through a lawn or a vein bulging under human skin. Other times the stem epidermis does not lift or bulge much and the miner's trail is simply discolored relative to the ground color of the stem. Bark miners occupy the equivalent niche in woody stems. Common stem and bark miners include agromyzid flies in the genus Ophiomyia ("snake fly") and moths in the genus Marmara, but other creatures are involved too.

Stem borers, like stem miners, may do some feeding right under the epidermis -- but their activities are not restricted to this region. Instead, they are often found deeper inside the stem, tunneling vertically through the ground tissue (such as the pith) and/or the vascular tissue. Sometimes nearly all of the stem interior is consumed, leaving little more than a flimsy collar of epidermis (at which point the plant may fall over!). More often, a stem borer's tunnel occupies only part of the stem in cross-section, and enough interior stem tissue remains for the plant to do its thing more or less normally. Affected stems sometimes discolor or swell, and lepidopteran or coleopteran borer larvae often drill holes in the epidermis through which they enter, exit, or expel frass. It is also common for there to be little or no external sign of a stem borer's presence. The agromyzid genus Melanagromyza is an example of a speciose grouping of mostly stem-boring flies (including the recently described M. vanderlindeni!) with which I have some familiarity, but stem borers are a diverse lot of insects from at least three different orders -- see below.

What follows is a sampling of some of the stem borers I have encountered in my insect investigations. Here, I group stem borers by order and include genus names of hosts along with thumbnails. I also lump petiole borers in with the stem borers.

FLIES

Phlox: Verbena: Andropogon: Polymnia:

Parthenocissus: Elymus: Gentiana: Arnoglossum:

Xerophyllum: Hieracium: Veronica: Equisetum:

Prenanthes: Urtica (two species): Pedicularis:

Cirsium: Achillea: Eutrochium: Lactuca:

Sanicula: Zizia: Scrophularia: Angelica:

Cryptotaenia:




MOTHS
Solidago: Hydrophyllum: Artemisia (two species): Lactuca:

Robinia: Zizia: Cirsium: Veronica:

Yucca: Ambrosia: Verbena: Lysichiton:

Scrophularia: Impatiens: Bidens: Nelumbo:

Juglans: Heracleum: Aesculus: Prunus (two species):