Flies in the family Empididae, while commonly found in aquatic environments, aren’t typically used as bio-indicators due to the difficulty in associating the adults, which are typically well-described, to the larvae which aren’t. This study attempted to associate larvae and adults in Utah and California by studying larvae morphology, rearing larvae and pupae, and observing ribosomal DNA fragments. For the DNA analysis, PCR was performed using the primers ITS 5 and RNA 2, which both target ribosomal genes. Gel Electrophoresis was then used to match the larvae with the adults and to differentiate between the genera. They found that the genera all created distinct enough bands to be able to tell them apart from each other, but it became more difficult at the species level for two of the genera. The species belonging to the genus Hemerodromia were easy to differentiate with electrophoresis, as were those of Chelifera. The larvae of the different genera could be differentiated using morphology alone, and the researchers were able to update keys with better illustrations. They suggested that the primers used in the study could be used for other Hemerodromiinae to associate larvae with adults, or at the very least distinguish between genera.
This study outline possible steps I might take if I want to try to use genetic markers to associate larvae with adults. Hemerodromiinae is the sub-family I will probably be dealing with the most, and the genus Hemerodromia has appeared in other literature from the area my samples came from.
Differentiation of Larvae of Metachela Coquillett and Neoplasta Coquillett (Diptera:Empididae:Hemerodromiinae) Based on Larval Rearing, External Morphology, and Ribosomal DNA Fragment Size
Journal of the North American Benthological Society
Vol. 18, No. 3 (Sep., 1999), pp. 414-419
Vol. 18, No. 3 (Sep., 1999), pp. 414-419
Great! So if your flies are unkeyable you have alternatives. Great to learn those molecular bio skills too.
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