Comparison of Biological Characteristics of Cryptolaemus montrouzieri Muls. (Col.: Coccinellidae) on Planococcus citri Risso (Hom.: Pseudococcidae) and Pulvinaria aurantii Cockerell (Hom.: Coccidae) in Laboratory

The coccinellid Cryptolaemus montrouzieri Muls. is an oligophagous predator that is used to control mealy bugs in the orchards and greenhouses. Citrus soft scale, Pulvinaria aurantii, as an active pest on citrus plants in North of Iran is also attacked by this predator. This research was conducted to study biological characteristics of C. montrouzieri on citrus soft scale and mealy bug, Planococcus citri. Initially, Cryptolaemus eggs were collected from colonies of two preys and reared in laboratory (14 L: 10 D, 25±1˚C, and RH 70 ±5%). The incubation period of eggs, 1st, 2nd, 3rd and, 4th larval instars, and total larval, prepupal, and pupal stages were studied on two preys. The developmental stages on two preys were not significantly different, except for the 4th larval instar at 1% and total larval stages at 5%. The sex ratio of male to female on two preys were not significantly different at 1% and was 1:1. Except for pre-oviposition period, other parameters including female longevity, average number of eggs laid per day, average total number of eggs laid per female and percentage of hatching were significantly different at 1% on the two preys. The average feeding of total larval period on eggs of mealy bug and citrus soft scale were 5715 and 7694, respectively that, the difference was significant at 1%. The results showed that some of the biological characteristics of Cryptolaemus on two preys were significantly different. Since the predator feeding on the eggs of citrus soft scale was higher than the mealy bug, it seems that this beneficial insect could be used for biological control of the citrus soft scale.