Female reproductive system of the decapitating fly Pseudacteon wasmanni Schmitz (Diptera: Phoridae)

• Autor(a) principal: Zacaro, Adilson A.
• Data de Publicação: 2003
• Outros Autores: Porter, Sanford D
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: https://doi.org/10.1016/S1467-8039(02)00049-X; http://www.locus.ufv.br/handle/123456789/24674
• topic: Ovary; Fire ant; Solenopsis; Biocontrol; Ovipositor; Brazil

Pseudacteon wasmanni is a South American decapitating fly that parasitizes workers of Solenopsis fire ants. We used light microscopy (historesin serial-sectioning stained with Haematoxylin/Eosin) and scanning electron microscopy to show and analyze internal and whole external views of the female reproductive system. All specimens analyzed (n=9) by light microscopy showed post-vitellogenic oocytes inside the ovaries. The lack of typical follicles (oocyte-nurse cell complexes) in all specimens suggests that oogenesis occurs during the pupal stage. The total number of eggs found ranged from 31 to 280 (X=142±73, SD). The egg has a slugform or torpedo shape (about 130 by 20 μm) with a pointed apex at the posterior pole as defined by the fly; the micropyle appears to be in a depression or invagination at the anterior pole. An acute hypodermic-like ovipositor is evaginated from the hard sclerotized external genitalia during egg laying. The existence of a muscular bulb associated with the end of the common oviduct suggests that the egg is injected into the ant's body by a strong contraction of the bulb which probably is stimulated by bending of several ventral sensilla. During contraction, the abdomen extends out along a large fold between the sixth and seventh tergites in such a way that the sclerotized genitalia is rotated ventrally into a slightly anterior orientation in preparation for oviposition.