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cultures, the larvae pupated within three days. Johnson and Hertig 

 (1961) stated that in laboratory cultures of neotropical flies ( Lu . 

 sanguinaria and panamensis ), adverse conditions, mainly too little 

 moisture, result in diapause of the 4th instar. In the indoor Lu . 

 diabol ica colony, larval quiescence occurred most often in response to 

 excessive or inadequate moisture, or poor diet, but in a few cases it 

 occurred when rearing conditions appeared to be optimal. Quiescence in 

 the outside colony was mostly temperature related, resulting in summer 

 aestivation and possibly winter hibernation. Larvae usually resumed 

 normal development with the restoration of favorable conditions, but 

 in some cases the quiescence was not readily reversible, indicating a 

 possible true diapause. 



Chaniotis (1967) reported facultative diapause in the 4th larval 

 stage of nearctic Lu. cal ifornica , Lu . stewarti , and Lu. vexator up to 

 230 days postoviposition. He concluded that the percent and amount of 

 diapause was related to generation and temperature, believing that the 

 1st generation of flies emerging from hibernation produced 

 nondiapausing larvae, and the 2nd and 3rd-generation flies produced 

 larvae of which only a portion diapaused. He further stated that the 

 higher the temperature, the less diapause occurred and that low 

 temperature should be regarded as the principal factor inducing 

 diapause in California species. He added that under optimal 

 conditions of temperature, humidity and food, a certain proportion of 

 2nd and 3rd-generation larvae entered diapause and suggested that 

 factors intrinsic to eggs, larvae or females are also involved. 



In contrast to Chaniotis 1 (1967) observations of California sand 

 flies, hot summer temperatures may also induce quiescence/diapause in 



