This is a video of a Polistes wasp feeding on oak sap.
From the Los Angeles Times in the USA:
The case of the red-shanked grasshopper
Knowledge of insects can solve crimes, stop diseases, grow better crops. But what happens if no one has the knowledge?
By Lynn Kimsey, LYNN KIMSEY is a professor of entomology and the director of the Bohart Museum of Entomology at UC Davis.
July 4, 2007
Two FBI agents and a Bakersfield police officer walked into the Bohart Museum of Entomology at UC Davis four years ago carrying a car radiator and air filter splattered with insects.
I’m the museum director, and they asked me and my entomologist colleagues whether we could tell where the car had been just by examining the dead bugs.
What the lawmen knew, but I wouldn’t learn for some time, was that the car had been rented in Ohio by someone they suspected in a murder. They theorized that the suspect drove to California, killed his family and then drove back to Ohio.
If, as the defendant claimed, he had never left Ohio, there would be no insects on the radiator from outside that region, reasoned one of the FBI agents. They knew the history of the rental car, that the prior drivers had never left Ohio. So if we found any insects from west of the Rockies, that would discredit the suspect’s alibi. …
Six insects told the story. Two were beetles that are known to live only in the eastern U.S. But then we found the large back leg of a grasshopper. Its markings revealed it to be a red-shanked grasshopper (Xanthippus corallipes pantherinus), found no farther east than Kansas and central Texas.
On the radiator was the unmistakable large golden paper wasp (Polistes aurifer), minus a few wings and legs. It can live as far east as Kansas, but it is most abundant in California. And then on the air filter we found two true bugs (Neacoryphus rubicollis and Piesma brachiale or ceramicum), their brightly colored, distinctively sculpted bodies largely intact. These species are found only in Arizona, Utah and Southern California. …
It seems like case closed. But there is a problem. The U.S. is losing the taxonomy expertise that makes it possible to identify insect bits on a car radiator, or the exotic mosquito hitchhiking in a container of lucky bamboo, or a stealthy caterpillar sheltered inside a flat of strawberries. I’ve been studying, teaching about and identifying insects for 30 years, but there are few specialists in the wings.
We as a culture have become overly enamored with technology. We’ve lost sight of the fact that it is still much cheaper and faster to have a specialist identify an insect by sight than to have a technician analyze its DNA. No DNA has been sequenced for 99% of insect species, so even if you get a usable sample from a car radiator, there’s nothing on file to match it against.
Crime and insects in the Basque country: here.
Polistes fuscatus wasps in the USA: here.