Analysis of biological traits of Anagyrus cachamai and Anagyrus lapachosus to assess their potential as biological control candidate agents against Harrisia cactus mealybug pest in Puerto Rico

Authors: AGUIRRE, MARIA - Fuedei; LOGARZO, GUILLERMO - Fuedei; TRIAPITSYN, SERGUEI - University Of California; DIAZ-SOLTERO, HILDA - Animal And Plant Health Inspection Service (APHIS); Hight, Stephen; BRUZZONE, OCTAVIO - Instituto Nacional De Tecnologia Agropecuaria

Submitted to: BioControl
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/11/2019
Publication Date: 7/30/2019
Citation: Aguirre, M.B., Logarzo, G.A., Triapitsyn, S.V., Diaz-Soltero, H., Hight, S.D., Bruzzone, O.A. 2019. Analysis of biological traits of Anagyrus cachamai and Anagyrus lapachosus to assess their potential as biological control candidate agents against Harrisia cactus mealybug pest in Puerto Rico. Biocontrol. 64:1-13. https://doi.org/10.1007/s10526-019-09956-y.
DOI: https://doi.org/10.1007/s10526-019-09956-y

Interpretive Summary: The Harrisia cactus mealybug is native to South America and attacks several species of cacti. Unfortunately, the mealybug was introduced into Puerto Rico and has established as an invasive species where it is attacking and destroying similar species of cacti. The reaction of native Puerto Rican cacti to attacks by the mealybug is substantially greater leading to failure of flowering and eventual death of both small and large plants of all species. Scientists with USDA, Agricultural Research Service, Center for Medical, Agricultural and Veterinary Entomology, Tallahassee, Florida, in collaboration with USDA-APHIS, the Argentine Foundation for the Study of Invasive Species, and Universities of California and Argentina conducted insect surveys and biological studies in South American and identified two species of wasps as the most promising candidates for biological control of the mealybug in Puerto Rico. These two wasps are being assessed further with additional studies to confirm that the wasps attack only the targeted mealybugs. After confirmation and approved permitting, the two wasps could be released into Puerto Rico together to generate better mealybug control than that produced by establishing just one parasitoid species.

Technical Abstract: The Harrisia cactus mealybug (HCM), Hypogeococcus sp. (Hemiptera: Pseudococcidae), is a serious pest in Puerto Rico, also threatening native cacti on many Caribbean islands, Mexico, Central and North America. In South America, its native area, various natural enemies keep HCM under control. A survey conducted in South America of Hypogeococcus sp. feeding on several species of Amaranthaceae, Portulacaceae and Cactaceae, revealed the presence of two parasitoids, Anagyrus cachamai and A. lapachosus (Hymenoptera: Encyrtidae), as prospective biological control agents for this pest. Rearing protocol to conduct mass production, specificity studies and several aspects of the biology of these species were studied under laboratory conditions in Argentina. Anagyrus cachamai and A. lapachosus successfully attacked early instars of Hypogeococcus sp., have a balanced sex ratio, exhibited a development time synchronized with that of the host, and presented differences in their reproductive biology (egg load at birth, ovigeny index, and sex ratio) and time of development. All these characteristics make these parasitoids promising candidates for introduction as biological control agents against the HCM pest in Puerto Rico.