Molecular Phylogenetic Placement of the Recently Described Armored Scale Insect Abgrallaspis aguacatae and Several Congeners (Hemiptera: Diaspididae)

ÔHassÕ avocado, Persea americana Miller, fruit being imported into California from Mexico are infested with high levels of a previously unknown species of armored scale insect (Hemiptera: Diaspididae). This species has recently been described and given the name Abgrallaspis aguacataeEvans,Watson&Miller.However, the validity ofmorphological characters used todiagnose genera within the tribe Aspidiotini (Diaspididae) is the subject of continued debate. Here, we seek to circumnavigate the inherent problems associated with interpretation of somewhat plastic phenotypic characters.Weuse two different nuclear gene regions (28S andElongation Factor 1 ) and three different analysismethods(maximumparsimony,maximumlikelihood, andBayesiananalyses) to infer phylogeny from DNA sequence data for 35 aspidiotine species. Our analyses suggest that the new species is misplaced in the genus Abgrallaspis Balachowsky and that this genus and several closely allied genera are paraphyletic or polyphyletic. The Þndings of our analyses are discussed speciÞcally in relation to the current placement of A. aguacatae and more broadly in relation to the longrecognized problem of deÞning generic boundaries between Abgrallaspis, Diaspidiotus Berlese, and Hemiberlesia Cockerell.