Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: February 28, 2012
Publication Date: N/A
Harrisia cactus mealybug (HCM), Hypogeococcus pungens (Hemiptera: Pseudoccidae) Granara de Willink (1981) is infesting and killing cacti in the southern coast of Puerto Rico, covering an area of about 1,400 km2. The 13 species of cacti occurring in Puerto Rico are threatened by this new pest; three of which are endemic, and two endangered. HCM may also be threatening Florida and Barbados. A biological control program has been initiated in Puerto Rico to search for natural enemies of HCM native to South America. Beyond its native range, HCM has been reported in Australia, the Caribbean, Europe, and North America. HCM were first described on the host family plant, Amaranthaceae, and its host range includes species from Portulacaceae and Cactacea. In collecting HCM in South America, we noticed biological differences when rearing HCM on the different host plants, and therefore we suspected that HCM may be part of a species complex. We must first clarify this situation in order to import the correct natural enemies. We asked the following questions: 1) Did HCM originate from Argentina? 2) Is HCM part of a species complex? 3) Are HCM populations plant-host specific? The mitochondrial cytochrome oxidase subunit I gene (COI) and the nuclear D2 Loop of the 28S gene were sequenced. Neighbor-joining and maximum parsimony phylograms of the COI sequence data clustered the various populations into 5-6 clades, most of them with strong bootstrap support values. A haplotype match was found in Florida, but not in Puerto Rico. With the exception of Florida, an association with host plant was also identified. The D2 sequence phylograms confirmed the presence of at least five mealybug species.