Guess the Pest! Week #8 Answer: Parasitized Aphid (Mummy)

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Bill Cissel, Extension Agent – Integrated Pest Management, University of Delawarebcissel@udel.edu

Congratulations to Bob Leiby for correctly identifying the parasitized aphid in the photograph and for being selected to be entered into the end of season raffle for $100 not once but five times. Everyone else who guessed correctly will also have their name entered into the raffle. Click on the Guess the Pest logo to participate in this week’s Guess the Pest challenge!

The aphid in the photograph has been parasitized by a tiny wasp, about 1/10th inch in length. The adult female wasp, referred to as a parasitoid, lays an egg in the aphid. When the egg hatches, the tiny white parasitoid larva develops inside the aphid which eventually kills the aphid. Once the parasitoid larva finishes its development, it pupates, causing the aphid body to turn tan or black depending on the species of parasitoid. An aphid that has been parasitized is referred to as an aphid mummy.

Highly magnified image of a Braconid wasp (parasitic wasp).

Parasitic wasps and other beneficial insects play a major role in keeping aphid populations in check in many cropping systems. For example, in small grains during heading, a ratio of one beneficial insect (lady beetle larva, syrphid fly maggot, lacewing larva, damsel bug or parasitic wasp) per 50-100 aphids is often sufficient to achieve biological control. Because of this, if you have an aphid infestation, it is always important to also note beneficial insect activity.

Early Aphid Occurrences: A Possible Result of Warmer Winter Temperatures

       Veronica Johnson, University of Maryland Department of Entomology

Aphids are small, early season pests that can occasionally reach damaging levels in small grain fields in Maryland. Strategies to control these insects should begin with correct pest identification and field scouting to determine infestation levels within a particular field.

Pest Identification:

Aphids are soft bodied, pear-shaped insects  with piercing-sucking mouthparts and a pair of “tailpipe-like” projections, or cornicles, emerging from their lower abdomen.  Adults can be winged or wingless, and the vast majority of aphids are female. A number of aphid species have been documented as either direct or indirect pests of wheat in Maryland. These include the bird cherry oat aphid, english grain aphid, corn leaf aphid, and the greenbug aphid. Continue reading Early Aphid Occurrences: A Possible Result of Warmer Winter Temperatures

Sorghum Growers Encouraged to Keep an Eye Out for Sugarcane Aphid this Season

Kelly Hamby, kahamby@umd.edu Assistant Professor/Extension Specialist, Department of Entomology

Ben Beale, bbeale@umd.edu Extension Educator, UME-St. Mary’s County

Sugarcane Aphid was found late last fall in Charles County, Maryland in a sorghum field that was being harvested for grain. Aphid populations were very high, with feeding present in the grain head and leaves. This is the first time that sugarcane aphid has been found in Maryland. While this aphid has caused substantial losses to sorghum in states to our South, it is unknown if the aphid will be present early enough and at high enough populations to cause significant injury in Maryland. Growers are encouraged to monitor sorghum fields through the summer for the presence of sugarcane aphid. We suspect sugarcane aphids are most likely to arrive later in the season in Maryland. Continue reading Sorghum Growers Encouraged to Keep an Eye Out for Sugarcane Aphid this Season