Question
I live in the BC Interior, Canada, and have recently purchased a house with a weeping willow. Also a few months ago purchased 2 used, insulated, dog houses that we put under the willow tree. There are very tiny little black bugs with orange legs, EVERYWHERE, mostly originating around the willow tree and dog houses. But in 1 day they are in the lawn, on our house etc... We were told they might be a weevil but that they don't really live up here and they don't seem to have the hooked nose or "horn" as shown in pictures. We used a pesticide last yesterday called "sevin" work for a bit now they are everywhere again. Please help...

Answer
Sounds like WILLOW FLEA WEEVIL

Willow (and poplar) leaves may be severely browned by these small insects from mid-summer on. Leaves may retain their normal shape and remain on the trees but often browned leaves drop abundantly in late August and September. Depending on severity of attack, the normal green color of leaves attains a bronze or brownish cast starting in July and becoming increasingly apparent through August.

Adults are tiny, elliptical, black weevils (0.1 inch long) with orange legs that eat out tiny circular holes in the foliage, usually from the underside, and leave only the opposite leaf-surface over the hole. Adults first appear in mid-May as new leaves are developing. Holes continue to be made into July.

Eggs are laid in leaf punctures by late June. Larvae (grubs) soon hatch and feed as leaf miners within the leaf tissue, making blotch mines in the upper tissues of each leaf. Surfaces over the mines become dark brown and blister-like and are very conspicuous. Mines are completed by mid to late August at which time adults are again abundant and feeding. With cool weather adults hibernate for the winter in soil, sod, and under loose bark of trees.

Bifenthrin, chlorpyrifos or pyrethrin are registered for control of the willow flea weevil and imported willow leaf beetle. The insecticide should be applied according to instructions for shade tree pests, during early June (1-11) immediately after the leaves have flattened out. A second spray application may be required in early July (1-4) to protect new growth from living adults that have moved in from surrounding unsprayed trees.  


If the tree is too tall to spray with liquids I would use Bayer Advanced Tree and Shrub Insect Control insecticide. This is applied to the soil around the tree and the roots will carry it to the leaves and when the beetles feed they will be killed. It is not fast acting so results may take several weeks to show up depending on the rainfall or the amount of water to move the insecticide. One application will protect the tree for the year. Here is a web link to this product check with your local garden type store for it. http://www.bayeradvanced.com/tree-shrub-care/products/12-month-tree-shrub-insect...

They will not kill the tree but if they defoliate the tree for a couple of times the tree will be weakened and lose some growth. When they complete a life cycle the beetles will disappear but will usually have 2-4 generations per year so expect the tree to try to leaf out again and the beetles will hatch out a new generation to defoliate the tree. The Bayer product will protect the tree from the other generations feeding on the leaves.