Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Photo#1687491
Tiny broad-nosed weevil? - Pseudohylesinus pini

Tiny broad-nosed weevil? - Pseudohylesinus pini
Presidio, Dragonfly Creek, San Francisco County, California, USA
June 30, 2019
Size: ca 2.75 mm
Caught in Malaise trap 27 June - 4 July 2019.

Images of this individual: tag all
Tiny broad-nosed weevil? - Pseudohylesinus pini Tiny broad-nosed weevil? - Pseudohylesinus pini Tiny broad-nosed weevil? - Pseudohylesinus pini Tiny broad-nosed weevil? - Pseudohylesinus pini Tiny broad-nosed weevil? - Pseudohylesinus pini

Moved
Moved from Pseudohylesinus.

Moved
Moved from Beetles.

Hey Ken
It's possible this is actually a scolytine. Might be Pseudohylesinus.

Perhaps something close to this one:


We could probably rule it out with a picture of the head at an angle where the eyes and antennae are visible.

 
Thanks Marc -
I added a quick home photo of the eyes and antennae, let me know if that's not sufficient and I can take better Z-stacked images next weeked at the museum.

 
Hey Ken
This is helpful. It’s definitely Pseudohylesinus. I think it’s either sericeus or pini and I’m leaning toward the less common pini. Most of the characters in the key will require examination of the specimen, but we might be able to tell based on the proportions of the frontal rectangle. For this, we’ll need a shot of the frons straight on, kind of like this one...

Try to make sure the surface of the frons is not at an angle to the lens (like tipped forward or back). We’ll need it as straight on as possible to get an accurate vertical measurement.

 
Hi Marc -
thanks again, I've added two photos of the frons, I hope one is what you were looking for. The sclerotized plate that I think is the frons is tilted at an angle with respect to the head and I tried to get a straight-on shot (esp. in "frons2")...

These Malaise trap specimens are going to CAS, but they can be loaned to anyone if you want to see the specimen. If I am lucky enough to collect a series of the same species, I don't think it's a problem to send several out and let the expert pick 1-2 to keep for their own collection...

 
Nice
Okay, I think the first angle more closely matches the figures in Blackman's revision. It may be slightly tilted which would make the vertical distance slightly longer, so the ratio may be slightly underestimated. So I'm measuring the rectangle ratio (height/width) to be 1.14. The shape of the pronotum indicates a male. P. sericeus males should have a ratio of 1.06 and P. pini males should be 1.20. P. pini males also have stout pronotal scales that are nearly circular, which seem to be the case on this beetle. Size and distribution are within range for both species. Characters that I cannot see include the interstrial granules (their relative abundance and confusion toward the base). P. pini should be less abundant and less confused. I think the evidence is sufficient to place the images under P. pini on BugGuide, but to make a firm determination for the museum I would want to have a look at the specimen. If you want to loan it for this purpose, I could have it shipped back to you pretty quickly. Also, if the museum has any other undetermined scolytines, you could include them and I'd be happy to examine them all.

 
Thanks
Marc! I will send you an email offline, appreciate your help with this one, as always.