#AphidsOfHarperAdams— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020
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
These aphids are found on all cereals, including rice and maize, without host alternation.— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020
Most grass (Poaceae) species, as well as some rushes (Juncaceae) and sedges (Cyperaceae), are also suitable host plants.
Alate (winged) individuals develop in early summer leading to more colonies establishing throughout the rest of summer.— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020
Development of alate individuals is largely due to increasing population density and declining food quality. pic.twitter.com/yKJYEV3B2S
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.— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020
BYDV infection manifests as leaf yellowing and stunting. pic.twitter.com/yaAwF4v39G
How about natural enemies?— Joe Roberts (@Dr_Joe_Roberts) March 4, 2020
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