Monday, December 10, 2007 - 9:29 AM

Mealybug (Hemiptera: Pseudococcidae) phylogeny and classification revisited

Nate B Hardy,, University of California, Entomology Department, One Shields Avenue, Davis, CA, P. J. Gullan, University of California - Davis, Entomology, One Shields Ave, Davis, CA, and Chris J Hodgson, The National Museum of Wales, Department of Biodiversity and Biological Systematics, Cathay's Park, Cardiff, United Kingdom.

The mealybugs (Hemiptera: Coccoidea: Pseudococcidae) are a speciose and ubiquitous group of sap-sucking plant parasites, many of which are very serious agricultural pests. There has been much work on the alpha-level taxonomy, amounting to the description of more than 2000 species, but suprageneric relationships remain poorly known. Downie & Gullan reviewed proposed schemes for a mealybug subfamily-level classification and used DNA sequence data from three nuclear genes to infer the mealybug phylogeny. They recognized 3 subfamilies: the Rhizoecinae, the Phenacoccinae, and the Pseudococcinae. Within the Pseudococcinae, they recognized the tribes Pseudococcinae, Trabutinini, and Planococcini. With the exception of the Trabutinini, none of these groupings were well-supported. We improve our estimation of the mealybug phylogeny by: (1) increasing the taxon sampling by ca. 50%; (2) adding a morphological character matrix; and (3) performing mixed model Bayesian and Maximum Likelihood inference procedures. We recover two primary clades within the Pseudococcidae, and to these we apply the subfamily names Phenacoccinae and Pseudococcinae. Within the Phenacoccinae, we recover support for the monophyly of the hypogeal mealybugs (Rhizoecini), and within the Pseudococccinae, we find support for the tribes Pseudococcini, Trabutinini, and Planococcini.

Species 1: Hemiptera Pseudococcidae Pseudococcus longispinus (long-tailed mealybug)
Species 2: Hemiptera Pseudococcidae Maconellicoccus hirsutus (pink hibiscus mealybug)
Species 3: Hemiptera Pseudococcidae Phenacoccus aceris (apple mealybug)