Armored Scales and Their Parasitoids on Commercial Avocados Grown in California or Imported from Mexico.

Levels of armored scales (Hemiptera: Diaspididae) on Mexican Hass avocados imported into California over May 2008-June 2009 were monitored on 135 trucks entering the state via the Blythe border station, the entry point receiving the highest volume of fruit. Levels of live sessile scales were 3.9-fold higher than indicated in a previous survey (September 2007-April 2008) although levels of live eggs and crawlers were similar to previous levels. A survey of avocado fruit in California infested with armored scales detected four species known to be endemic but failed to find any of the seven exotic Diaspididae entering the state on Mexican fruit. Monitoring of Mexican armored scales on imported avocados from September 2007 to December 2010 recovered 10 species of parasitoids predominated by two species of Signiphora Ashmead (Hymenoptera: Signiphoridae). One of these species, Signiphora flavopalliata Ashmead, comprised 36% of all collected Mexican parasitoids and is a known hyperparasitoid. A survey of armored scale parasitoids present on commercial California avocados detected 17 genetic signatures, with only four of these in common with those detected on imported Mexican fruit. The implications of these findings are discussed.

Subforaminal bridges in Hymenoptera (Insecta), with a focus on Chalcidoidea.

Variation in structures of the posterior surface of the head in Hymenoptera is compared and interpreted according to theories of head capsule evolution, with focus on understanding previously baffling conditions in the superfamily Chalcidoidea. Features are investigated separately without first classifying subforaminal bridges into subcategories. In Proctotrupomorpha (including Chalcidoidea), Ceraphronoidea and some Ichneumonoidea, there are multiple posterior pits associated with the tentorium. In most examined Hymenoptera with a subforaminal bridge, there was a differentiated median area, typically with highly variable microtrichia. This area is elevated in Cephoidea and Pamphilioidea, but is not elevated in other Hymenoptera. Subforaminal bridges in Apocrita previously classified as hypostomal bridges are discussed in the context of A.P. Rasnitsyn's hypothesis that relative importance of adult feeding drives subforaminal bridge evolution.

Phylogeographic structure, outbreeding depression, and reluctant virgin oviposition in the bean thrips, Caliothrips fasciatus (Pergande) (Thysanoptera: Thripidae), in California.

Bean thrips, Caliothrips fasciatus, is native to western North America. Once considered a pest of several crops in its native area, its pest status has waned over recent decades. However, due to its habit of aggregating in the navel of navel oranges, bean thrips remains economically important because some countries importing oranges from California have designated it a quarantine pest. Despite continued propagule pressure, bean thrips has never established outside North America. We examined genetic variation in mitochondrial DNA among Californian populations of C. fasciatus and found that potentially two cryptic species are present (supported by Kimura 2-P distances): a common widespread form B and a rarer form A with a very limited distribution. Form B showed strong phylogeographic structure, with many haplotypes having a limited geographic distribution. Inter-population crossing experiments between three geographically isolated populations of form B resulted in the production of some female offspring, indicating a degree of compatibility between these populations of this haplodiploid species. However, substantial outbreeding depression was also detected. A low frequency of offspring production by hetero-population pairs was evidence of pre-mating isolation, while post-mating isolation was also evident in the elevated mortality of fertilized eggs in successful hetero-population crosses. One surprising finding was the total lack of offspring production by virgin females when isolated individually. However, virgin females did produce sons in the presence of other virgin females. A test for the presence of Wolbachia showed that form B was not infected, but that some populations of the rarer form A were.

Preliminary phylogeny of Encarsia Förster (Hymenoptera: Aphelinidae) based on morphology and 28S rDNA.

Species of Encarsia Förster (Hymenoptera: Aphelinidae, Coccophaginae) are economically important for the biological control of whitefly and armored scale pests (Hemiptera: Aleyrodidae, Diaspididae). Whereas some regional keys for identification of Encarsia species are now available, few studies have addressed relationships within this diverse and cosmopolitan genus because of unreliable morphological data. Nuclear sequences of the D2 expansion region of 28S rDNA were determined from 67 strains of 24 species representing 10 species groups of Encarsia, 2 strains of Encarsiella noyesi Hayat, and 1 strain of Coccophagoides fuscipennis Girault. Analysis of molecular data alone and combined with morphological data resolves many nodes not resolved by morphology alone and offer insights into which morphological characters are useful for supporting group relationships. All analyses that include molecular data reveal Encarsia to be paraphyletic with respect to Encarsiella. If monophyly of Encarsia is constrained, the relationships are the same but with a different root within Encarsia, and these trees are presented as an alternate hypothesis. The luteola and strenua species groups are shown by both morphological and molecular data to be monophyletic, whereas the inaron group, the E. nigricephala + luteola group, and the E. quericola + strenua group are supported only by molecular data. The aurantii and parvella species groups are not supported in any of the analyses. The utility of morphological characters for defining species group relationships is discussed.