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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Insect Behavior and Biocontrol Research » Research » Publications at this Location » Publication #308662
Title: Geographical range and laboratory studies on Apanteles opuntiarum (Hymenoptera: Braconidae) in Argentina, a candidate for biological control of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America

Author
item GONALONS, CAROLINA - University Of Buenos Aires
item VARONE, LAURA - Foundation For The Study Of Invasive Species
item LOGARZO, GUILLERMO - Foundation For The Study Of Invasive Species
item GUALA, MARIEL - Foundation For The Study Of Invasive Species
item RODRIGUERO, MARCELA - University Of Buenos Aires
item Hight, Stephen
item Carpenter, James

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2014
Publication Date: 12/10/2014
Citation: Gonalons, C., Varone, L., Logarzo, G., Guala, M., Rodriguero, M., Hight, S.D., Carpenter, J.E. 2014. Geographical range and laboratory studies on Apanteles opuntiarum (Hymenoptera: Braconidae) in Argentina, a candidate for biological control of Cactoblastis cactorum (Lepidoptera: Pyralidae) in North America. Florida Entomologist. 97(4):1458-1468.

Interpretive Summary: Caterpillars of the Argentine cactus moth feed on prickly pear cactus and have become an invasive pest in the southeastern U.S. The moth’s spread into western U.S. and Mexican desert ecosystems may have severe negative consequences for the many species of prickly pears and the associated native species that rely on this plant. Scientists with USDA Agricultural Research Service and the Argentine Foundation for the Study of Invasive Species are studying insects that attack the cactus moth in its native home of Argentina. One recently identified natural enemy is a wasp that lays its eggs in the caterpillar stage of the cactus moth. The cactus moth caterpillar dies as the wasp offspring mature and feed. Laboratory studies and collections of different cactus feeding caterpillar species revealed that the wasp only attacks the cactus moth, even though different caterpillars are found feeding alongside the cactus moth. The wasp was widespread in Argentina and attacked cactus moths at most prickly pears sites checked by the scientists. Rearing methods were developed for the wasp on cactus moth in the laboratory. The wasp was sent to a Florida quarantine facility to evaluate the wasps’ use of North American caterpillars as hosts. If the wasp does not attack native caterpillars and is determined to be safe for release in the U.S., then the wasp will help control the invasive cactus moth.

Technical Abstract: The cactus moth Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is a pest that threatens native Opuntia spp. in North America. Control tactics developed and implemented against this invasive pest successfully eradicated the moth in Mexico and on barrier islands in the United States. However, with the cancellation of the regional management program in the United States, the expansion of the moth’s geographical range is no longer restricted. Hence, an integrated approach including biological control is proposed to regulate the population of C. cactorum in North America. Field surveys of the recently described parasitoid, Apanteles opuntiarum Martínez & Berta, were carried out within the C. cactorum native range in Argentina, and laboratory studies were conducted to develop a parasitoid rearing protocol. Apanteles opuntiarum was the most common parasitoid of C. cactorum and their field distributions were similar. In the laboratory, the parasitoid’s reproductive success was maximized when one or two female wasps were exposed to 30 host larvae within a 500 ml container. Laboratory reared females were less successful at parasitizing hosts than field collected females. In spite of the success achieved with laboratory rearing, male bias was observed throughout the experiments. Because this bias might be related to the presence of the reproductive parasite Wolbachia, both laboratory colony and field collected individuals were screened and Wolbachia was detected. This study provides useful field and laboratory information on (1) laboratory rearing techniques for A. opuntiarum; (2) developing host specificity test protocols for studies under quarantine conditions; and (3) selecting parasitoid populations that best match the climatic conditions present in the C. cactorum invaded areas of North America.