|
INSECTS ON ASPEN: LEAF ROLLERS Leaf bundles or rolls on aspen are made by many different insects, including attelabid weevils (Coleoptera), tortricid moths (Lepidoptera), cecidomyiid gall midges (Diptera), and pamphiliid sawflies (Hymenoptera). |
||
|
Leaf-rolling weevils (Coleoptera: Attelabidae) |
||
|
Byctiscus populi (Coleoptera: Attelabidae) Byctiscus populi occurs only on aspen. The eggs and larvae can be found inside the roll, which includes only a single leaf. The adults are slightly smaller than those of B. betulae (below). |
 |
 |
|
Two Byctiscus populi females rolling a leaf on P. tremula. The rolls are often made cooperatively by several beetle individuals. |
Leaf rolls made by Byctiscus populi on Populus tremula. |
|
|
Byctiscus betulae (Coleoptera: Attelabidae) A common polyphagous species which makes leaf bundles on birches (Betula spp.), aspen, and willows (Salix spp.). In contrast to the rolls made by B. populi (above), the shelters of this species involve many leaves each. The adults resemble those of B. populi, but they are slightly larger. |
 |
 |
|
Leaf bundle of Byctiscus betulae on Populus tremula. |
Byctiscus betulae in the process of constructing a leaf shelter for its larvae on Populus tremula. |
|
|
Moths (Lepidoptera) |
||
|
Moths (Lepidoptera: several families) Moth larvae belonging to many different families construct leaf shelters on aspen. The rolls are kept in shape by strands of silk, so they are easy to separate from the shelters made by attelabid beetles (above). Because the leaf petioles are not cut, rolls made by moth larvae do not dry like the beetle rolls. |
 |
 |
|
Leaf roll made by unidentified moth larva on Populus tremula. Note the thin white strands of silk that hold the roll in place. Silk is also present inside the roll. |
Leaf rolls made by lepidopteran larvae and Byctiscus beetles often occur on the same aspen individuals. On this branch, only the uppermost rolls are made by moths. |
|
|
Gall midges (Diptera: Cecidomyiidae) |
||
|
Dasineura populeti (Diptera: Cecidomyiidae) Many different cecidomyiid midges induce galls on aspen (click here to see more aspen galls). Oviposition by Dasineura populeti causes an abnormal growth response in aspen leaves, which ultimately leads to the formation of upward-curled leaf rolls. Each roll houses numerous small whitish midge larvae. |
 |
 |
|
Leaf roll induced by Dasineura populeti on Populus tremula. |
The leaf rolls may be induced on both sides of the leaf blade. |
|