Black swallowtail, Papilio polyxenes

If you’ve seen a large, mostly black butterfly lately, chances are it was a black swallowtail, a very common butterfly of eastern North America.  The colorful caterpillars feed on many herb garden plants while the adults nectar at a variety of flowers. To learn more about this species and how to encourage it in your garden, read this article…

Iris Borer

Iris borer is the most serious pest of iris in Wisconsin. Iris plants attacked by iris borer will discolor, wilt, and die during late June and July. On close examination of affected plants, a pinkish-white caterpillar can be found feeding on the inside of rhizomes. This factsheet covers identification and control of this serious pest.

Insect Pest Management for Greenhouses

This handy chart lists pesticides that are most effective against common greenhouse pests such as aphids, scales, leafminers, spider mites, and thrips. Formulation, effectiveness, cautions, and other details are provided.

Managing Thrips in Greenhouses

R. Chris Williamson, Turf and Ornamental Specialist Revised:  4/25/2004 Item number:  XHT1022 Western flower thrips, Frankliniella occidentalis, are likely the most serious pest of greenhouse crops in the world.  Thrips have spread throughout the horticulture industry on plugs, cuttings, and small plants.  Because of thrips’ small size (1∕16 inch) and tendency to remain hidden in […]

Managing Mites in Greenhouses

R. Chris Williamson, UW Turf and Ornamental Specialist Revised:  4/25/2004 Item number:  XHT1021 Several types of mites can cause serious damage to a variety of greenhouse crops.  Among the most common mite species are the broad mite (Polyphagotarsoeneumus latus), carmine spider mite (Tetranychus cinnabarinus), cyclamen mite (Phytonemus pallidus), the Lewis spider mite (Eotetranychus lewisi), and […]

Managing Aphids in Greenhouses

R. Chris Williamson, UW Turf and Ornamental Specialist Revised:  4/25/2004 Item number:  XHT1020 Aphids can be persistent and serious pests in the greenhouse.  Because of their high reproductive capability and resistance to numerous insecticides, they can be difficult to control.  Aphids are sucking insects that damage greenhouse crops by causing curling and distortion of young, […]

Fungus Gnats and Shore Flies in Greenhouses

Fungus gnats are considered a cosmetic problem in most situations, but larval feeding on plant roots has been associated with root rots in greenhouse settings. Shore flies (Scatella stagnalis) are another nuisance insect and are often confused with fungus gnats in the greenhouse.


Karen Delahaut, formerly UW-Madison Fresh Market Vegetable Program Revised:  4/26/2004 Item number:  XHT1129 Mealybugs are slow-moving, small, oval insects that are covered with a white, cottony wax.  They are tropical insects that are typically only found on perennial foliage plants, and rarely on flowering or bedding plants.  They can infest all plant parts including the […]


Karen Delahaut, formerly UW-Madison Fresh Market Vegetable Program Revised:  4/26/2004 Item number:  XHT1127 Whiteflies are not true flies although they look fly-like.  They actually belong to the same order of insects as scales, aphids, and mealybugs: the order Homoptera.  There are several species of whiteflies that can infest greenhouses including the greenhouse (Trialeurodes vaporariorum), sweet […]


Authors: David Lowenstein and Russell Groves, UW-Madison Entomology Last Revised: 05/22/2020 X-number: XHT1045 Wireworms are the larvae of several species of click beetles (Family Elateridae).  These beetles flip into the air with an audible click when turned on their backs.  Wireworms feed primarily on grasses (including grass crops such as corn) but have a broad host range that […]

Field Ants

Phil Pellitteri Revised:  1/25/2011 Item number:  XHT1204 One of the most common ants in Wisconsin is the field ant (Formica spp.).  This ant is noted for producing large mounds that can ruin the aesthetics of home lawns, make lawn mowing difficult, and interfere with the growth of herbaceous and woody ornamentals. Appearance:  Field ants are […]

Cicada Killer Wasps

Phil Pellitteri, UW Insect Diagnostic Lab Revised:  1/4/2011 Item number:  XHT1198 Cicada killer wasps have become very common in the southern half of Wisconsin.  These solitary wasps are up to 1½ inches long, and their black and yellow coloring makes them look like giant yellow jackets. Life Cycle:  Adult cicada killer wasps appear from mid-July […]

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