This month’s issue of the Journal of the Lepidopterists’ Society includes an article of mine* discussing two leaf-mining moths I’ve written about here previously.
The first is an oak-mining eriocraniid that I had expected to be Dyseriocrania griseocapitella when I collected the leaf mines, but the adults were clearly something else, which I tentatively identified as the southeastern species Eriocraniella mediabulla. I wrote that “just two eriocraniids [are known to] occur in the Northeast; Dyseriocrania griseocapitella, which mines leaves of various oaks . . . and Eriocrania semipurpurella, which mines birch leaves.” This statement was based on looking at the draft key to oak leaf mines in my book manuscript; when I wrote the blog post I had forgotten to consider the possibility that there are other northeastern eriocraniids that have been described from caught adults, without any associated natural history information. In fact, in Don Davis’ 1978 revision of North American Eriocraniidae, he described Eriocrania breviapex and Eriocraniella platyptera from a few specimens caught in Ithaca, New York, and nothing has been published about them since.
I sent one of the moths to Jean-François Landry, and after consulting with Don Davis he confirmed that it was Eriocraniella platyptera. In my paper I discuss how the leaf mine of this species differs from those of Dyseriocrania griseocapitella and Eriocraniella mediabulla, and now the (95-step!) key to oak leaf mines in my book manuscript is a little more complete. As I mentioned in my previous post, E. mediabulla is only known from Georgia and the Gulf Coast states. The adults of that species are emerging right now; here is one Robert Lord Zimlich spotted at his house in Mobile, Alabama on March 10.
In addition to rearing the two adults of Eriocraniella platyptera, I had several parasitoid wasps emerge, all in the genus Pnigalio (Eulophidae). Christer Hansson examined them and reported that they belong to at least two different species, neither of which fits into the existing key to the genus. New species? We won’t know until someone decides to revise the genus Pnigalio, but here’s what they look like:
Eriocraniids all have a single generation, with larvae mining newly opened leaves in the spring, then burrowing into the ground and lying dormant until they emerge as adults the following spring. So when I found this Eriocraniella mine on Gambel oak (Quercus gambelii) in Colorado last July, it was much too late to have any hope of finding larvae to try and rear.
If this one from Colorado is one of the described species, it would have to be Eriocraniella longifurcula, which Don Davis described from adults collected in Arizona. That species has not been reared, but it is believed to be responsible for mines found on a hybrid of Quercus gambelii and Q. arizonica near where it was collected. I found mines of five other moths on Gambel oak in Colorado, all of which are probably undescribed species. I managed to rear three of them, but I don’t expect they will get names any time soon.
The other species I wrote about in my new paper is the currant-mining moth from Oregon I discussed here. DNA barcoding of a moldy old larva had revealed a 97% match with Acanthopteroctetes bimaculata (Acanthopteroctetidae). Adults of that species have been collected in Oregon and California, but nothing is known about its natural history, and 97% is in that gray area that may or may not indicate a species match. The larvae that I had found in Oregon in October 2012 turned out to be very common on the same species of currant (Ribes cereum) in Colorado last July. So I now can show you what a live Acanthopteroctetes larva looks like:
Unfortunately, although I collected a good number of these from several different sites, I once again failed to keep any alive long enough to pupate. I think success would require monitoring larvae as they develop and not collecting them until they are just about mature. In other words, someone who lives in the western US needs to take this on. Any takers?
* Eiseman, Charles S. 2016. Notes on the larval hosts and habits of some North American Eriocraniidae and Acanthopteroctetidae. Journal of the Lepidopterists’ Society 70(1):79-81.