Host stage preference of Aenasius bambawalei (Hymenoptera: Encyrtidae), the parasitoid of cotton mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae), under choice and no-choice access

The cotton mealybug, Phenacoccus solenopsis Tinsley, is a phytophagous insect with high populations causing serious damage to the Chinese hibiscus shrubs (Hibiscus rosa-sinensis L.) from south of Iran. This research was conducted to determine the host preference of Aenasius bambawalei Hayat when had choice or no-choice access to different stages of cotton mealybug. Moreover, biological characteristics and body size of wasps when reared on third nymphal instar and adult females was studied under laboratory condition. According to the results, female wasps did not parasitize the first nymphal stage. The second nymphal stage was parasitized without any adult wasp emergence. The results revealed that the percentage of mealybug mummified, and sex ratio (% female) was significantly higher when mealybug hosts were parasitized at adult females compared to third nymphal stage, in both choice and no-choice access. The developmental times (days) and body size (hind tibia length and antenna length) of A. bambawalei females and males developing in cotton mealybug adult female was significantly longer than those reared on third nymphal instar. The results indicated the high control ability of A. bambawalei, on the older growth stages of cotton mealybug. It is hoped that this parasitoid wasp can be used as a biological agent to control Ph. solenopsis, on the Chinese hibiscus shrubs, H. rosa-sinensis.