Giant Willow Aphid
Tuberolachnus salignus
Giant Willow Aphid
Tuberolachnus-salignus2 by Pabs-wsm (CC BY-SA 4.0)
1 of 6
Tuberolachnus-salignus2 by Pabs-wsm (CC BY-SA 4.0)
1 of 6
Now playing
Deal with aphids organically: Method 4
Deal with aphids organically: Method 3
Deal with aphids organically: Method 2
Giant willow aphid is regarded the largest of it's kind, sometimes reaching 6mm big. They are sometimes described as mysterious because scientists still know shockingly little about their biology. Unlike most aphids, giant willow aphids feed on stems and twigs, penetrating the bark with their adapted mouthpieces. Like most species of aphid, the aggregate, forming large colonies. They are grey-brown with black dots, but more interestingly, possess a distinctive dorsal fin like a shark. The purpose of this is yet to be proven by scientists; however, it's thought it may be used for camouflage when feeding in thorned trees.
Traits

These aphids can attract sooty moulds to the area infected.

An abundant food resource for predatory insects like harlequin ladybirds and their larvae.
Appearance
Adults are grey-brown and large for an aphid (5-6mm). They can be winged or wingless. The abdomen is grey-brown with dark spotting with a distinctive dorsal fin. When disturbed, adults will lay on their backs and kick the legs!
Nymphs tend to look like adults but are smaller in size, are slightly paler, and lack wings.
Unlike other aphids, this species is most active during months which are cold and next to freezing. In summer, they are seen less.
Symptoms
Copious amounts of honeydew may be evident near the site aphids are present.
Honeydew can encourage the growth of black mould, so this may be notable too.
Damage seldom permanent.
Activity
Diurnal
Personality
Order
Hemiptera
Family
Aphididae
Metamorphosis
Incomplete
Distribution
Worldwide
Biological treatment
These aphids provide an abundance of food for wildlife active during autumn.
Despite their large numbers, they don't seem to affect overall tree health.
Chemical treatment
Aphids have many natural enemies. It's not advised to chemically treat trees with these insects.