Black Vine Weevil

2011 June 18

Here’s another beetle that the girls caught for me when we went to Otter Lake on May 22, 2010. This is a pretty good sized weevil, almost a centimeter long, which is positively huge as weevils go around here. She’s had a rough life – in addition to missing part of her left foreleg, she also doesn’t have any antennae anymore.

Based on the shape of the body and snout, she’s clearly one of the broad-nosed weevils, and looks to me like one of the black ones in the genus Otiorhynchus. And from the brown spots on the back, I’d go so far as to guess that she’s a Black Vine Weevil, Otiorhynchus sulcatis.

I say “She”, because all of the Otiorhynchus species in North America are invasives from Europe, and most of them (including O. sulcatis) came over as parthenogenic females. So, in North America there are no males (although males exist back in Europe). BugGuide says there are about 14 species in this genus that have been introduced in the US so far, out of some 150 species that exist back in the Old Country.

These weevils evidently don’t have wings any more, they’ve just converted their wing covers into shells. So, to get around they either have to walk, or hitch-hike on things that humans haul around. They have a great deal of time for travelling, because the adults can evidently live for up to three years. So they’d make OK pets, I suppose.

Being parthenogenic, they can breed pretty fast. And being invasives, they haven’t really developed a lot of local natural enemies yet. And, being opportunistic herbivores, they are pests of a lot of different plants, particularly woody ornamentals. The adults eat notches out of the edges of leaves (which are unsightly), while the grubs live underground and eat roots. Sometimes they will completely girdle a bush or shrub at ground level, and kill it. So, if you see notches in leaf edges of a shrub, you might want to do something about it. One simple thing is to lay a sheet or board under the shrub, whack the branches a bit, and then pour the weevils that fall onto the sheet into a container so that you can do away with them. Freezing is usually good, although dousing them with alcohol or gasoline is more traditional. Fire is probably excessive.

Aaaannnnnnnnd, after writing all that and preparing those pictures, Sam just caught a second specimen yesterday that looks almost exactly the same, except for the niggling detail that she has both of her antennae, and all of her legs. So, if you want to see what they look like when they are all there, here you go:

A note: I added a new set of categories over on the right-hand side. It categorizes the postings by the month that the pictures were taken (rather than just the month they were posted). This might help in narrowing down the search if you are trying to identify something. The numbers obviously vary quite a lot, as there are many more bugs to photograph in the summer than in the winter. Still, there are at least a few for every month of the year. Even January has eight postings (including my most popular page, the Carpet Beetle Larva), with a fair number of insects coming out during the thaw that we usually get around the middle of the month. The slowest months are December and February, probably because in December there are so many distractions keeping me from hauling out the camera, and in February it is just really, really cold.

3 Responses
  1. July 1, 2011

    How about hitting them with bricks? I’ll bet their pretty susceptible to that. And anvils. And grand pianos dropped from tall buildings. Think Warner Brothers cartoons and I’ll bet you can find plenty of ways to do away with them.

    Just trying to help.


  2. July 2, 2011

    Sure! I could use tiny little jeweler’s anvils!

  3. July 2, 2011


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