''Curculio glandium'' is a species of carpophagus weevil, known as the acorn weevil. It is native to eastern North America. It eats by a rostrum, an elongated snout, that is used for piercing. Male/Female differentiation can be determined using the rostrum as female's are longer. The larvae are short, and cylindrical in shape, and move by means of ridges on the underside of the body. Adults can reach a length of 4 to 8 mm.
Similar species: Beetles
By Paul Dirksen
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Uploaded May 9, 2020. Captured May 8, 2020 13:17.
comments (9)
These can be quite tricky to identify, but first impression would lead me more to C. glandium than to C. nucum (general appearance, colour/pattern and I see no clear comb of hairs along the apical part of the suture). The comb is a good character, but it can sometimes be worn ...
So the question is: What tree/plant did you find it on?
Cheers, Arp Posted 5 years ago
... I think you have the two species exactly reversed :o)
It also makes sense, as nucum is a tad larger on average (nucum: 6-8,5mm; glandium 4-7,5 mm). With those numbers, the intraspecific variation in size is quite substantial for both and it makes quite a world of difference if you see a big and small specimen next to each other.
Note that sizes for weevils are given as "front of eyes to tip of abdomen/wings", so _without_ the rostrum.
With both glandium and nucum the length of the snout is subject to sexual dimorphism, with the snout on the female being much longer than on the male (the females need to bore deep into the acorn/hazelnut to dig a hole for oviposition).
I would suggest that you exchange the IDs on the two photos. It's hard to be 101% sure from photo, but that way the two pictures make much more sense to me. Posted 5 years ago
thank a lot mate. Posted 5 years ago