#euaresta festiva

[aldenthesnazzy]

lotta euaresta festiva gathering on this plant call that a euaresta festival

[jonnysinsectcatalogue]

Giant Ragweed Fruit Fly - Euaresta festiva

The common name given to this insect has been seen online a fair amount, but it doesn't appear to be official. Nevertheless, the name is an appropriate one as it indicates the host plant of this yellow-bodied, iridescent colored Fruit Fly: giant ragweed (Ambrosia trifida if we need to be specific). To be clear, the insect itself isn't a giant. If you had to ballpark it, it's around the size of the Leafhopper seen in Pictures 1, 3 and 6, so let's say 1cm long at most. To identify this insect without evidence of a host part, you'll need to carefully examine the patterned wings and ensure the wing cells and spots are a match, as well as identifying a golden-yellow thorax. I think the identification of this Fly is quite secure since it appears today on its host plant, or at least one plant of the ragweed family. If you have allergies to ragweed pollen this may be one insect you might avoid at first glance, but if it leads you to ragweed, you can simply go in the opposite direction of where the Fly flies to. Despite the multi-colored eyes (which tend to be associated with Flies that bite), this insect is docile and has sucking mouthparts that will not pierce skin. Likely they feed on nectar from flowers.

This is one specie of Fly where whether it's male or female cannot be determined by looking at the head and eyes. Instead, you should turn your attention towards the abdomen of the specimen and look for a black and brown ovipositing extension at the tip. Since there's no ovipositor here, our specimen today is a male. If this male is looking for a female, I hope he's prepared for the courtship display he'll need to demonstrate to prove his worth. Resources and other photographs suggest that this specie of Fruit Fly goes through elaborate routines before mating takes place. The male will display his patterned wings, rock his body without moving his legs (like how a Stick Insect wobbles), sidestep around with great vigor and extend his mouthparts to receive a "kiss" from a receptive female. It's brief, but if the mouthparts make contact, the prospects of a male look very successful. The final step is if the male can successfully move behind the female, and only then will he lower his wings. However, a female G.R. Fruit Fly won't allow an unfit male to sneak behind her. If both sides are reciprocated, then the female can place her eggs on the developing ragweed flowers, which will allow the larvae to develop in the fruits/seed of the plant. They'll emerge next summer as fully developed Flies and repeat the cycle, hopefully making some impact on reducing the spread of giant ragweed.

Pictures were taken on August 20, 2023 with a Google Pixel 4. Fruit Flies will be featured again next week with another new specie.