Heterospilus, undescribed species, Costa Rica
My more astute readers may have noticed that Myrmecos Blog has been uncharacteristically quiet this week. I do apologize, but I have a regular research job aside from blogging that periodically requires attention.
I’ve been assembling genetic and morphological data from 100 or so wasps in the hyperdiverse genus Heterospilus. These are small insects, typically under a centimenter in length, that attack stem-boring grubs like beetle and moth larvae. This week I am patching up the holes in the molecular data matrix, and this requires bench time and sequence editing time.
Why are we interested in these wasps?
Well, Heterospilus is a big part of the “Taxonomic Impediment” in the Neotropics. They are among the most common wasps collected in biodiversity surveys, yet in our study sites in Costa Rica not a single one of the 400+ species has been described by taxonomists. It is hard to compare data among sites or monitor the decline of biodiversity without a stable taxonomy.
As part of the project we’re trying to make sense of the bewildering array of colors, shapes, and sizes by mapping them to a phylogeny (that is, a genealogy of how the species are related). If we can discover the patterns of how traits evolve we’ll both improve our basically non-existent understanding of the wasps and be more able to craft a taxonomy structured around evolutionary lineages.
Our preliminary results indicate that the color of the wasps’ antennae evolve extraordinarily slowly. Much more slowly than traits like ovipositor length that are directly related to parasitic behavior, and more slowly even than the number of antennal segments themselves. Considering that color is a trait most entomologists consider highly labile (color variants within species are common- as in peppered moths), we were surprised and we’re hoping to pick up some clues- from a pile of preserved museum specimens- why this might be so.
Anyway. Back to work.