September 2005. A paper on the rearing of a parasitoid attacking the Pink pineapple mealybug.
Effect of pink pineapple mealybug hosts on Anagyrus ananatis Gahan size and progeny production
Raju R Pandeya and Marshall W Johnsonb
aDepartment of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, Honolulu, HI 96822, USA
bDepartment of Entomology, University of California, Riverside, CA 92521, USA
Studies were conducted to improve the colony production of Anagyrus ananatis Gahan (Hymenoptera: Encyrtidae) when reared on the pink pineapple mealybug (PPM), Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae). Parasitization of large PPM (>0.85 mm length) by A. ananatis resulted in an almost 3:1 ratio of female:male offspring. A strong positive correlation (r2 = 0.8935) was found between PPM weight and parasitoid size (i.e., length). Male parasitoids were not as food limited as females when the mealybug host was small. Despite the ability of A. ananatis to parasitize all host stages except crawlers, gravid adult female PPM produced larger parasitoids with higher fecundity. Allowing PPM to continue feeding on squash following parasitization produced larger parasitoids. However, for A. ananatis propagation it is more efficient to remove PPM from squash hosts and size them (via sieving) before exposing them to the parasitoid. Mealybugs >0.6 mg in weight and >0.5 mm in size can be used for parasitoid rearing to produce female A ananatis (>1.4 mm length) that exhibit fecundities similar to those for A ananatis that developed on PPM that fed on squash following parasitization (28 progeny per female). Furthermore, to maintain an A ananatis female-biased sex ratio, PPM hosts >0.6 mm (medium size) would be preferable for use in parasitoid colony production. The length and width of PPM mummies were good predictors of the sex and body size of the parasitoid contained within, and may be potentially used as important indicators of parasitoid quality and fitness in a mass production system.
Keywords: Pink pineapple mealybug; Dysmicoccus brevipes; Anagyrus ananatis; Parasite–host interaction; Fecundity; Mummy; Host size