Influence of temperature on oviposition by Dermacentor andersoni (Acari: Ixodidae)

The effects of temperature on oviposition by Dermacentor andersoni (Stiles) was examined using replete females ranging in weight from 30 to 1,198 mg. Survivorship was >96% during the preoviposition periods and declined during oviposition period. Egg production peaked earlier and at greater levels as temperature increased. Longevity, preoviposition period, and oviposition period declined as temperature increased. Replete weight had minor effects on measures of time, but smaller females tended to have greater longevity and preoviposition periods, and shorter oviposition periods. Temperature and replete weight both had large effects on measures of oviposition success such as the amount of eggs laid, the conversion efficiency index, and daily egg production. Lower temperatures and replete weight resulted in greater oviposition failure, and reduced egg production and conversion efficiency. Oviposition was greatly inhibited at 10 degrees C, suggesting this is near the lower temperature limit for development. However, egg production was reduced at temperatures < 20 degrees C, suggesting that the northern edge of the distribution may be influenced by the effects of temperature on oviposition.