Natural Enemies of the Harrisia Cactus Mealybug and Other Hypogeococcus Species (Hemiptera: Pseudococcidae) in Puerto Rico: Identification and Taxonomic Notes on Primary and Secondary Parasitoids.

Primary and secondary parasitoids of Hypogeococcus spp. (Hemiptera: Pseudococcidae) on Cactaceae, Amaranthaceae, and Portulacaceae were reported from field surveys conducted in Puerto Rico, USA, since 2009. Resident natural enemies of the Harrisia cactus mealybug (HCM), Hypogeococcus sp., which is devastating native cacti in Puerto Rico and threatening cacti in the adjacent Caribbean islands, were documented prior to the planned introductions of non-native biological control agents from South America against this pest. Two species of Encyrtidae (Hymenoptera: Chalcidoidea) were recorded as primary parasitoids of the HCM on Cactaceae: Leptomastidea hypogeococci Triapitsyn, which was the most common, and Anagyrus quilmes Triapitsyn, Logarzo & Aguirre. Another primary parasitoid, Acerophagus sp. near nubilipennis Dozier (Encyrtidae), was also reared from a different Hypogeococcus sp. on Amaranthaceae and Portulacaceae. Hyperparasitoids, usually via L. hypogeococci, included Prochiloneurus narendrani Noyes & Triapitsyn (Encyrtidae), Pachyneuron sp. (Hymenoptera: Pteromalidae), Chartocerus elongatus (Girault), and Chartocerus niger (Ashmead) (Hymenoptera: Signiphoridae). Cheiloneurus chrisiantorresi Triapitsyn sp. n. (Encyrtidae) is newly described and illustrated; its status as a suspect hyperparasitoid of Hypogeococcus sp. on Amaranthaceae and Portulacaceae, along with that of Cheiloneurus sp., will need to be verified. The recorded HCM predators include one species of Chamaemyiidae (Diptera), Leucopina bella (Loew), and three species of Coccinellidae (Coleoptera): Cryptolaemus montrouzieri Mulsant, Decadiomus austrinus (Gordon), and Scymnobius flavifrons (Melsheimer).

Studies on the Biology of Hypogeococcus pungens (sensu stricto) (Hemiptera: Pseudococcidae) in Argentina to Aid the Identification of the Mealybug Pest of Cactaceae in Puerto Rico.

Hypogeococcus pungens Granara de Willink, sensu stricto, is a serious pest of cacti in Puerto Rico threating many Caribbean islands. A classical biological control program for H. pungens was initiated for Puerto Rico in 2010 with a survey for natural enemies of H. pungens in its native range of Argentina. Biological differences were observed between populations of H. pungens sampled on Amaranthaceae and Cactaceae. Molecular studies suggested that H. pungens populations from different host plant families are likely a complex of species. Our objective was to study the biology of H. pungens sensu stricto on specimens collected in the same locality and host plant as the holotype [Tucumán Province, Argentina; Alternanthera pungens Kunth (Amaranthaceae)]. We were interested in the reproductive biology of females, longevity and survival of adults, the effect of temperature on the development, and nymph performance (survival and development) on five Cactaceae species. We found that H. pungens s.s showed marked biological differences from the populations collected on Cactaceae and exported to Australia for the biological control of the cactus Harrisia spp. The main differences were the presence of deuterotoky parthenogenesis and the fact that H. pungens did not attack Cactaceae in the laboratory. Our results provide biological evidence that H. pungens is a species complex. We propose that the population introduced to Australia is neither Hypogeococcus festerianus Lizer y Trelles nor H. pungens, but an undescribed species with three circuli, and that the Hypogeococcus pest of cacti in Puerto Rico is not H. pungens.