Molecular detection method developed to track the koinobiont larval parasitoid Apanteles opuntiarum (Hymenoptera: Braconidae) imported from Argentina to control Cactoblastis cactorum (Lepidoptera: Pyralidae)

Authors: SRIVASTAVA, MRITTUNJAI - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; SRIVASTAVA, PRATIBHA - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; KARNA, RATNA - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; JEYAPRAKASH, AYYAMPERUMAL - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; WHILBY, LEROY - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; ROHRIG, ERIC - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; HOWE, AMY - FLORIDA DEPARTMENT OF AGRICULTURE AND CONSUMER SERVICES; HIGHT, STEPHEN; VARONE, LAURA - FUEDEI

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/17/2018
Publication Date: 6/14/2019
Citation: Srivastava, M., Srivastava, P., Karna, R., Jeyaprakash, A., Whilby, L., Rohrig, E., Howe, A.C., Hight, S.D., Varone, L. 2019. Molecular detection method developed to track the koinobiont larval parasitoid Apanteles opuntiarum (Hymenoptera: Braconidae) imported from Argentina to control Cactoblastis cactorum (Lepidoptera: Pyralidae). Florida Entomologist. 102(2):329-335. https://doi.org/10.1653/024.102.0207.
DOI: https://doi.org/10.1653/024.102.0207

Interpretive Summary: A small parasitic wasp from Argentina is being studied in a Florida quarantine facility as a potential biological control agent against the Argentine cactus moth, a pest of native prickly pear cactus in the southeastern U.S. Before the parasitoid can be approved for release into the wild, studies are conducted with native U.S. cactus-feeding caterpillars to ensure that the parasitoid attacks only the Argentine cactus moth. Obtaining robust test results have been difficult because the caterpillars from the dry, hot, desert-like conditions from western U.S. do not survive well during the tests in the humid, moist, laboratory conditions of the Florida quarantine. Scientists with USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Tallahassee, Florida and the Florida Department of Agriculture and Consumer Services, Division of Plant Industry, Gainesville, Florida, developed a genetic identification tool of the Argentine wasp to identify the wasp larvae inside caterpillar hosts whether the caterpillar stays alive or dies. This genetic identification has enabled scientists to determine if caterpillars challenged with stinging wasps die because of rearing problems or because they are parasitized. The project to test the safety of releasing the Argentine wasp on different hosts has advanced, and to date, no non-target caterpillars that have died during rearing have been parasitized by the wasp. Caterpillars of the targeted Argentine cactus moth have been identified to contain the genetic material of the wasp.

Technical Abstract: Apanteles opuntiarum Martínez & Berta (Hymenoptera: Braconidae) is a native natural enemy of the cactus moth, Cactoblastis cactorum Berg (Lepidoptera: Pyralidae) in Argentina, where the two species are believed to have co-evolved. Cactoblastis cactorum is an established invasive pest in the US that is rapidly spreading through the southeast. Apanteles opuntiarum was imported from Argentina and reared at the Division of Plant Industry containment facility in Gainesville, Florida, for study as a possible biocontrol agent for release in the US against C. cactorum. A DNA barcode was developed to enable the identification of the reared parasitoid population. The mitochondrial cytochrome oxidase 1 (CO1) gene of the A. opuntiarum reared in Florida containment was found to be identical to its Argentine founders, and distinctly different from the CO1 sequences of all other reported Apanteles species in the NCBI GenBank. Additionally, the AoF1 and AoR1 primer pair developed in this study specifically amplified the CO1 gene of A. opuntiarum and did not amplify the CO1 gene of the host C. cactorum. Therefore, the CO1 gene fragment identified in this study has the potential to be utilized as a DNA barcode specific for A. opuntiarum that can aid in tracking and identifying this parasitoid inside hosts.