Dale sends in this one.
There’s a poor color choice — cartoon blood is always red!
There’s the fact that mosquitoes don’t overeat and burst. (“In simpler terms, when the ventral nerve cord is severed, a mosquito has no sense of being full. It will continue to consume blood until it quadruples its body weight, whereupon it explodes. So unless you or a friend have the capabilities of performing neurosurgery, you won’t be seeing a mosquito “explode” anytime soon.”)
Even if we allow latitude for cartoon science and mentally color the blood red, what’s the joke here? Is the name Corelli a clue?
Comics I Don't Understand 
All it says in the dialog is “overate”, there’s no indication there (nor in the artwork) that the deceased mosquito actually exploded (like Mr. Creosote” did). It could just be like what sometimes happens to fish.
Just for the sake of comparison, a search for “mosquitos” at GoComics turned up three “anthropomorphic” examples, all from “Speed Bump” (in 2004, 2006, and 2012):
You walk into a restaurant and see a dead body and blood splattered everywhere. Clearly murder. In mosquito world, it isn’t nearly as cut and dried. That’s the joke.
“He” is the problem, since male mosquitos drink nectar, not blood.
“He” is the problem,
Yes, isn’t he just!
There’s also this one: https://www.pinterest.com/pin/519391769534292109/
@deety: Indeed!
Gary Larsen said that one of his mosquito cartoons resulted in lots of mail informing him that it’s the female mosquito that drinks blood, but no mail informing him that mosquitos don’t talk or wear clothes or live in houses.
Here’s a link for the cartoon that M.A.R.N. referred to.
Nothing in comics is trickier than the conventions about anthropomorphic animals. My rule is that if an animal feature is key to the joke, get it right. This rule is broken a lot. Comic writers, especially Webers, are lazy.
@ MiB & Downpuppy – One reason that readers may have sent Larson those complaints about incorrect scientific details was that his track record for getting most of the details right was so much better than average. There are plenty of other comics for which such suggestions would simply be a waste of time.
P.S. @ Downpuppy – Getting back to your superb observation (about gender), perhaps Hilburn should have included a bowl of (shrivelled) fruit on the table.