Investigation on the storage possibilities of Rhyzobius lophantae Blaisdell (Coleoptera: Coccinellidae) at different temperatures and periods

Abstract

Storage of natural enemies at low temperatures has an important role in biological control programs. It is an very critical factor that the stored individuals is used without losing their characters such as longevity, survival, fecundity, etc. In this study, the storage possibilities of Rhyzobius lophantae Blaisdell (Coleoptera: Coccinellidae) adults under low temperatures (4 A degrees C and 12 A degrees C) for four different periods (10, 20, 30 and 40 days) were investigated. The survival rates and life span of adults (male and female), daily and total egg numbers laid by females stored at 4 A degrees C and 12 A degrees C for 10, 20, 30 and 40 days were determined. The survival rates of adults stored at 4 A degrees C for 10 and 20 days were found to be 94.54% and 58.02% respectively. However, no adults stored at 4 A degrees C for 30 and 40 days were observed to survive. The highest survival rate was 88% for the adults stored at 12 A degrees C for 10 days. The average daily laid egg numbers were 12.51 and 9.37, and total egg numbers were 850.30 and 738.30 of adults stored at 4 A degrees C for 10 and 20 days, respectively. The decrease in daily and total egg numbers of females stored at 12 A degrees C was observed with increasing storage period. There was no significant difference in longevities of male and female stored at 4 A degrees C and 12 A degrees C. These results show that short-term storage at low temperatures does not affect certain properties of the predator when compared to 12 A degrees C and storage periods.