Romanian Agricultural Research, no.31, 2014 (SCI-Expanded)
The present study evaluated the mean effect of temperature, humidity, leaf wetness time, rainfall, soil moisture and photoperiod on parasitism rate of Sunn Pest (SP) Eurygaster integriceps Put. (Heteroptera: Scutelleridae) eggs under natural conditions Trissolcus semistriatus Nees. These values were recorded by HOBO device until 20-30% SP eggs of were in the anchor-shaped stage. Egg parasitism rates of the SP were significantly, positively correlated with rainfall and temperature, and not significantly correlated with humidity, leaf wetness time, soil moisture and average sunlight time. The results of multiple regression analysis produced the equation Y = -50.662 + 16.833 R + 4.105 T [where Y = Parasitism rate (%), R= Rain (mm), T = Temperature (°C)] both averaged over the period from beginning of April when egg parasitoids began to emerge from overwintering site, until the second week of May, when 20-30% of eggs were in the anchor - shaped stage. The findings suggest that the rain and temperature had a positive impact parasitism rate of the SP eggs.