Grape curculio and "flying ticks"

Hello, everyone, Recently I've received questions about a weevil that looks suspiciously like grape curculio. First, a few words about the grape pest. Grape curculio is a reddish brown to black weevil which overwinters in the ground cover and leaf litter. Adults become active about the time of grape bloom. Adults feed on leaf tissue for about 2 weeks, and then females cut holes in young berries and insert an egg. Larvae are pale, legless, with a brown head capsule. The larvae feed within berries for about 3 weeks. When ready to pupate, larvae drop to the soil. The pupal stage lasts 3-4 weeks. Emerged adults feed on foliage until overwintering. The insect in question now, the cause of questions, is superficially similar - almost black in color, between 2-3 mm in length, with an almost round outline in dorsal view. This species, however, is the yellow poplar weevil, also know as tulip poplar weevil, or sassafras weevil. Adults of this species also emerge from leaf litter in the spring, and mate during May to early June. Eggs are inserted into the midribs of yellow poplar (tulip poplar), sassafras and magnolia - all common plants in our area. The larvae are leafminers, and the pupal stage in passed within mines. Adults emerge in mid to late June. These new adultos are active for much of the season before entering overwintering quarters. As I mentioned these are superficially similar in appearance. The adults of yellow poplar weevil are marked by striations or grooves on the elytra (wing covers). The prothorax - the section between the head and wings - is relatively small. Becuase of its size and round shape, the species is sometimes and incorrectly called "flying ticks" by the public. Weevils are entirely plant feeding! Two views of yellow poplar weevil follow:

In contrast, the dorsal surface of grape curculio is marked by several broad bumps, giving a more robust appearance. The prothorax is larger, relative to that of the yellow poplar weevil. These differene are best viewed with some good magnification.

The yellow poplar weevils, though numerous at times, are of no concern in the vineyard. More later, Doug