Skip to main content
ARS Home » Research » Publications at this Location » Publication #240960
Title: Molecular markers discriminate closely related Encarsia spp. (E. diaspidicola and E. berlesei): candidate biocontrol agents for white peach scale in Hawaii

Author
item De Leon, Jesus
item NEUMANN, GABOR - US Department Of Agriculture (USDA)
item Follett, Peter
item Hollingsworth, Robert

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2009
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The white peach scale (WPS), Pseudaulacaspis pentagona Targioni-Tozetti (Hemiptera: Diaspididae) is a serious economic pest of papaya in Hawaii. In 2006, Encarsia diaspidicola Silvestri (Hymenoptera: Aphelinidae) was imported from Samoa to perform host-range studies. Another potential future candidate for WPS includes E. berlesei Howard, which closely resembles E. diaspidicola and these species have at times been confused. The objectives of our work were to 1) genetically characterize both Encarsia spp. by implementing a phylogenetic approach inferred by the cytochrome oxidase subunit I gene (COI) and ISSR-PCR DNA fingerprinting (ISSR-PCR) and 2) develop species-specific COI molecular markers that discriminate the two Encarsia spp., in addition to using the markers to detect parasitism of WPS. The COI sequence data readily discriminated the two Encarsia spp. as 46 base pair differences were observed between the two; of the 46 base pairs, eight led to amino acid substitutions. The levels of COI genetic divergence between the two species was 9.7%. ISSR-PCR discriminated the two Encarsia spp. as each was observed with fixed species-specific DNA banding patterns, making ISSR-PCR a diagnostic tool to discriminate the two species. The Encarsia-specific COI molecular markers were highly specific toward the species that they were designed for as cross-reactivity was not observed with non-target species. The E. diaspidicola-specific markers were successful at detecting parasitism of WPS by E. diaspidicola, conversely, E. diaspidicola was not detected in a non-target host, the native palm scale (Colobopyga pritchardiae). These molecular markers are important to the biocontrol program of WPS in Hawaii.