That's a penis.

Specifically, that's the penis of "Callosobruchus maculatus", or the 'Cowpea Weevil'.

The types of research which have been done and things which have been noted about this insect are weird to say the least. Specifically, someone decided they wanted to have a look at and photograph the males' penis. That had me realise there are scientists out there whose job descriptions probably include in the small print "responsible for studying and photographing as-of-yet unstudied/unphotographed penises of arthropods".

Also the nuptial gift of males to females is a spermatophore (blob containing their jizz) mixed with foodstuffs. A gift which the females will reject if they've got other stuff they could be eating.

Crazy how nature do that.

https://en.wikipedia.org/wiki/Callosobruchus_maculatus