The Grain Aphid: Aphids of Harper Adams with Dr Joe Roberts

4 March 2020

Over the next few days I am going to be giving a virtual tour of the various aphid cultures we maintain in the Jean Jackson Entomology Lab at @HarperAdamsUni.

Follow along using #AphidsOfHarperAdams!
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020

#AphidsOfHarperAdams

Species 1 - Grain aphid (Sitobian avenae)

Grain aphid adults are ‘medium-sized’ (1.3 - 3.3 mm) and spindle-shaped that are widespread throughout the world.

This species exhibits colour polymorphism with green and brown forms being most common! pic.twitter.com/4sDDoxkS0J
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020

These aphids are found on all cereals, including rice and maize, without host alternation.

Most grass (Poaceae) species, as well as some rushes (Juncaceae) and sedges (Cyperaceae), are also suitable host plants.
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020

Alate (winged) individuals develop in early summer leading to more colonies establishing throughout the rest of summer.

Development of alate individuals is largely due to increasing population density and declining food quality. pic.twitter.com/yKJYEV3B2S
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020

Feeding can directly result in reduced cereal yields but the biggest threat that grain aphids pose to yield is through transmission of plant diseases such as barley yellow dwarf virus (BYDV) through their saliva.

BYDV infection manifests as leaf yellowing and stunting. pic.twitter.com/yaAwF4v39G
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020

How about natural enemies?

A variety of natural enemies predate on grain aphids, including:

• Ladybirds (Coccinellidae)
• Hoverfly larvae (Syrphidae)
• Lacewing larvae (Chrysopidae)

These live in the upper vegetation of cereals and predominantly feed on aphids. pic.twitter.com/smWFpCf0cV
— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020