Nope, attention-grabbing titles just aren’t my forte.
Anyway, you may recall that last fall Owen Lonsdale and I published a paper describing 30 new species of agromyzid flies, two of which I found right along my driveway, and the rest of which I summarized here. That paper also gave new information on nearly 100 other species that already had names, gleaned from my first five years of rearing leaf-mining insects. During those five years, several other people around the US got inspired to start collecting leafminers too, and ended up contributing a number of specimens that were used in that paper. The #1 contributor was Tracy Feldman of North Carolina, and in recognition of his efforts, I set aside all of his rearing records of species that I hadn’t reared myself in other states (with the exception of Cerodontha feldmani) to be included in a separate paper dedicated to North Carolina Agromyzidae. That paper has just been published*, and in it Owen, Tracy, and I describe another nine new species.
One of these was a species Tracy first found in the spring of 2015 on a plant I’d never heard of, Carphephorus bellidifolius (Asteraceae), which apparently has the common name of “sandywoods chaffhead.” The leaf mines were partially on the upper surface…
…but the larvae often did most of their feeding on the lower surface, switching sides when they were almost mature. This is the underside of the same leaf that is shown above:
Naturally, all the mines Tracy collected that year turned out to be parasitized by eulophid wasps, so all we got were these:
He tried again the following May, with the same result. But then in late June, he found some more larvae, and these survived to form puparia…
…and emerged as adult flies within a few weeks:
When Owen examined the specimens, he informed us that this was a new species, so we named it Liriomyza carphephori—I always like to name species after their host plants if that name isn’t already taken.
Tracy and I were both surprised when Owen told us that the fly Tracy found mining leaves of Spanish needles (Bidens bipinnata) was the same species. Not only was the plant not very closely related (belonging to a different tribe of the aster family), but the mine seemed very different: on Bidens it was entirely on the upper surface and always started at the tip of the leaf, where it made a very contorted track before eventually meandering elsewhere in the blade.
I had collected similar mines in Vermont and in my front yard in Massachusetts on Bidens frondosa (“devil’s beggar-ticks”) in October 2016. The larvae were mining in leaves that had already turned completely red.
The adults that emerged the following spring proved to be the same species, so L. carphephori ended up being the one species in the North Carolina paper with paratypes from other states. The paratypes also included some older specimens of mine that we had mentioned in the first paper but hadn’t been able to put a name on yet because I had only reared females. One of these females had been reared from Bidens frondosa back in July 2014, and we discussed it as “Liriomyza sp. 3.” Two others had been discussed as “Liriomyza sp. 5,” and they were reared from Mikania scandens (climbing hempvine).
Mikania scandens, as it happens, is in the same tribe as Carphephorus (Eupatorieae) but has pointed leaves like Bidens. Interestingly enough, on Mikania some of the mines look like the ones on Bidens…
…and some are like the ones on Carphephorus: switching between the two leaf surfaces and not crammed into the tip of the leaf.
When I found these mines while doing botanical fieldwork back in August 2013, I was standing knee-deep in water. Some of them were already empty, and the larvae had glued their puparia to the undersides of the leaves—a useful adaptation to this habitat since they probably would have drowned if they had dropped from the leaves as Liriomyza larvae normally do.
Incidentally, one of those two females from Mikania emerged within a few weeks and the other not until the following spring. It’s always hard to know when to give up and throw away old puparia, and every once in a while I’m rewarded for hanging onto them until the next year.
One final note on Liriomyza carphephori: I’ve found similar leaf mines in Ohio on white snakeroot (Ageratina altissima), another member of the tribe Eupatorieae, and I predict these larvae will turn out to be the same species.
* Eiseman, Charles S., Owen Lonsdale, and Tracy S. Feldman. 2019. Nine new species of Agromyzidae from North Carolina, USA, with new host and distribution records for additional species. Zootaxa 4571(3): 301–333.