ARS | Publication request: Neotropical Thrypticus (Diptera: Dolichopodidae) Reared from Water Hyacinth, Eichhornia Crassipes, and Other Pontederiaceae

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 11, 2004
Publication Date: May 20, 2004
Citation: Ann. of the Entomol. Soc. Am. 97(3): 437-449 (2004)

Interpretive Summary: Nine new species of Thrypticus (Diptera, Dolichopodidae), associated with the aquatic plants of the Pontederiaceae family, were found in surveys conducted by the SABCL researchers in Parana-Paraguay basin and upper Amazon river . Five of them were reared from water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach which is originally from South America and became an invasive weed in the United States and many other countries around the world. This taxonomic identification was part of the research carried out in search for biological control agents for water hyacinth.

Technical Abstract: Nine new species of Thrypticus (Diptera, Dolichopodidae) are described from South America: T. truncatus, T. sagittatus, T. yanayacu, T. circularis, T. chanophallus, T. romus, T. azuricola, T. formosensis and T. taragui. All nine species were reared from the petioles and stems of aquatic and semiaquatic Pontederiaceae, five of them from water hyacinth, Eichhornia crassipes. These species appear to comprise the monophyletic truncatus Group characterized by a short and rather weakly sclerotised oviscapt, probably adapted to egg-laying in the soft petioles of Pontederiaceae. By contrast, most other Thrypticus species have a longer and more strongly sclerotised oviscapt for oviposition in hard-stemmed Poaceae, Cyperaceae, and Juncaceae. T. truncatus and T. sagittatus have potential as biological control agents for Eichhornia crassipes, which is a serious invasive weed in the Old World tropics. Notes are presented on the life history of these two species, based on field and rearing chamber observations.