We confirm the presence of a reproductive diapause in the over-wintering adult brood Homalodisca coagulata (Say) (Homoptera: Cicadellidae). Homalodisca coagulata possess 10 ovarioles, each with 1-4 discernable follicles, each follicle containing a developing oocyte. Ovaries of H. coagulata in diapause contained 1-2 under-developed oocytes, while those from non-diapausing females contained 3-4 oocytes, usually including one fully developed oocyte and another almost fully developed oocyte. Surveys of adult females indicated that oviposition declined from late Aug to mid Oct and ceased 15 Oct 2000. During reproductive diapause, mean ovariole length (1.23mm) and mean oocyte length (0.34mm) in females collected early in the season was significantly different from mean ovariole length (2.80mm) and mean oocyte length (1.95mm) for reproductively active ovaries in females collected later in the season. Oocyte and ovariole length was correlated with Julian date and photophase. A daily photophase threshold of 640 min marked the transition from reproductive diapause to the beginning of ovarian development in the field collected over wintering brood. In a related investigation, we determined that the presence of brochosomes on the wings is a good, but not an absolute indicator of an ovipositing female.
Species 1: Homoptera Cicadellidae Homalodisca coagulata (Glassy-winged Sharpshooter)
Keywords: ovarian morphology, reproductive diapause
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