Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2010
Publication Date: 1/21/2011
Citation: Rohrig, E.A., Shirk, P.D., Hall, D.G., Stansly, P.A. 2011. Larval development of Diaphorencyrtus aligarhensis (Hymenoptera: Encyrtidae) an endoparasitoid of Diaphorina citri (Homoptera: Psyllidae).. Annals of the Entomological Society of America. 104:50-58. Interpretive Summary: The wasp, Diaphorencyrtus aligarhensis, is an imported biological control agent being released in Florida to control the Asian citrus psyllid that transmits the citrus greening disease. Scientists at the USDA ARS, Center for Medical, Agricultural and Veterinary Entomology, Insect Behavior and Biocontrol Research Unit and the University of Florida have examined larval development inside the citrus psyllid nymphs in order to find better methods to rear this important biocontrol agent. The time of each larval stage was determined and the physical parameters of the stage were established. It was found that when the eggs of the wasp were laid in a specific stage of the psyllid nymphs, the developmental time for the wasp was shortened by 25%. This should provide a unique means of facilitating the production of this wasp for augmentive release to control the Asian citrus psyllid.
Technical Abstract: The encyrtid koinobiont endoparasitoid Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal) is an imported biological control agent being released in Florida against the Asian citrus psyllid, Diaphorina citri Kuwayama. The eggs and early larvae were found free-floating within the hemocoel. Larvae were soft-bodied with no observable hairs, bristles or external appendages, such as anal vesicles, in any instar. By the 3rd instar, larvae had begun attaching to nymphal tissues by anal secretions which provided a means of orienting within the host nymph. The penultimate and last instar larvae were found with their posterior anchored in the head/thoracic region of the host with their head oriented towards the posterior of the host nymph. Prior to the beginning of the prepupal stage, the host nymph was turned into a mummy and glued to a plant surface apparently requiring some secretions from the wasp larva. Development from oviposition to adult eclosion of D. aligarhensis took approximately 16 d when oviposition occurred in 2nd through early 4th instar nymphs although this time was shortened by four days (25%) when the wasps oviposited in mid-4th instar D. citri nymphs. This reduction in developmental time did not affect wasp fertility or lifespan and may offer a significant approach to improved rearing of this wasp for augmentative releases to control the Asian citrus psyllid.