Species: Elm Sack Gall Aphid (Tetraneura ulmi)
Family: Aphids (APHIDIDAE)
Category: Insects (Other)
Location: Widespread
A. Insects (Other)
More extensive information on insects can be found in a separate blog post.
B. Aphids (APHIDIDAE)
Aphids form a very large insect family of sap-suckers. They are generally considered to be a pest although in their abundance they provide nourishment for countless larger insects and birds. They are soft-bodied, pear-shaped insects. Aphids are usually green, but can be red, brown and even white.
Gall mites (and aphids) are too small to be seen by the naked eye - and to be photographed without specialist high magnification equipment. They are therefore exceptions to the rest of the species listings on this website - along with gall wasps - in that their existence in the Cemetery is established not by direct sight but by the evidence of their activity, the nail galls and leaf galls that their activity causes.
C. Elm Sack Gall Aphid (Tetraneura ulmi)
The Elm Sack Gall is a protuberance that grows on the surface of leaves of the English Elm. Inside the gall is the nymph of an aphid, Tetraneura ulmi. When female nymph aphids start feeding on the upper side of a leaf, the leaf reacts by forming a pimple on the upper side. These pimples expand as the nymph feeds and produce offspring. The galls are abandoned in summer, but the insect's life cycle will return it to fresh leaves the following spring.
Images
Elm Sack Gall Aphid
Inside each Elm Sack Gall is the nymph of an aphid, Tetraneura ulmi. The galls are abandoned in summer, but the insect's life cycle will return it to fresh leaves the following spring.
Elm Sack Gall Aphid
Inside each Elm Sack Gall is the nymph of an aphid, Tetraneura ulmi. The galls are abandoned in summer, but the insect's life cycle will return it to fresh leaves the following spring.
