I’m slowly making my way through the photos I took last summer, and I just got to the conclusion of an interesting series that started with this leaf I was given on June 22:
The leaf is from hairy honeysuckle (Lonicera hirsuta), a species that is listed as Endangered here in Massachusetts. I was given the leaf by a botanist at the state’s Natural Heritage & Endangered Species Program with the hope that I could determine what the leafminer was. No leafminer has been reared from this particular honeysuckle species, but based on what miners are known from other honeysuckles, I can say that the larva was a fly in the genus Aulagromyza (Agromyzidae). My best guess is that it is none of the six described Aulagromyza species that are known to feed on honeysuckle in North America. Long, linear, greenish mines have been reported from a similar plant, limber honeysuckle (L. dioica), in Ontario, and these were tentatively associated with an undescribed Aulagromyza species that is known from a single female reared from “Lonicera columbiana” (a plant that doesn’t exist) in Montana. So I’m thinking it’s either that or… something else.
But that’s all beside the point. The point is, a healthy mature Aulagromyza larva would pop out of its leaf and form a puparium like this…
…from which an adult fly would emerge:
(This fly is Aulagromyza luteoscutellata, which makes much shorter, wider mines that are common on introduced Asian bush honeysuckles.)
But if you look at the leaf mine photo above, you’ll see that there are a couple of objects toward the end of the mine. Here’s a backlit detail of the relevant portion:
The object at right is the remains of the fly larva, which was devoured by a parasitoid braconid wasp in the genus Colastes (or a related genus in the subfamily Exothecinae). We know this because the object at left is the wasp’s cocoon.
Normally, the braconid larva would pupate within the cocoon and then the adult would chew a hole at one end and emerge:
On July 5, an adult wasp did chew its way out of the cocoon in the hairy honeysuckle leaf…
…but it was a eulophid wasp, which as a larva had devoured the braconid larva within its cocoon.
I probably rear a lot more hyperparasitoids than I realize, so it’s always nice to see a clear case like this.