Influence of Temperature and Photoperiod on Development and Oviposition of the Pecan Leaf Scorch Mite, Eotetranychus hicoriae,

The life cycle of the pecan leaf scorch mite (PLSM), Eotetranychus hicoriae (McGregor), was studied at 15.5°, 21.1°, 26.7°, and 32.2°C and 30-50% RH on pecan leaf discs. Initial studies at constant illumination (24:0 LD) demonstrated a negative correlation between developmental time and temperature. No eggs hatched at 15.5°C. At a photoperiod of 10:14 and 21.1°C, females exhibited diapause morphology and did not oviposit. Shortening of the photophase resulted in an increase in developmental time for both sexes. Oviposition studies on pecan seedlings at the above temperature regimes showed maximum daily oviposition occurred at 26.7°C. There was no significant difference between oviposition on seedlings and leaf discs. No significant difference was found in the total eggs deposited by mated vs. virgin females. The presence of a tritonymph stage was not confirmed.