Daily changes in weight and egg output were determined for engorged Rhipicephalus san- guineus females held under different combinations of temperature and humidity from the day they dropped from dogs until their death. Longevity was temperature-dependent, and was shortened sig- nificantly by a high saturation deficit between 20 and 30 C. Temperatures below 10 C and above 40 C were tolerated for only short periods; maximum longevity occurred at 10 C. Egg output was related to the weight of the engorged tick. The maximum number laid by a single female was 5,414. Eggs were deposited between 15 and 40 C with most being laid between 20 and 30 C. In magni- tude, a constant 15 C was as detrimentally cold to egg production as 35 C was detrimentally hot. Regardless of temperature, the amount of moisture in the atmosphere, down to completely desiccating conditions, did not affect egg production. Temperatures below 20 C markedly extended the pre-ovi- position and oviposition periods. A few engorged females absorbed some moisture from an atmosphere of 93% relative humidity at 15 and 25 C. A high saturation deficit shortened the pre-oviposition periods between 20 and 30 C, and shortened the oviposition periods between 20 and 35 C. The length of the oviposition period was affected only by the physical environment, not by biological factors such as the weight of the engorged female or total egg output. Daily egg output usually reached a peak a few days after egg laying began, and was reached most quickly at 30 C. The number of eggs on the day of maximum output was related positively to the total number of eggs laid. The optimal conditions for egg laying under darkness were 30 C and dryness.
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Gordon K. Sweatman (1967) studied this question.