Molecular Markers Discriminate Closely Related Species <I>Encarsia diaspidicola</I> and <I>Encarsia berlesei</I> (Hymenoptera: Aphelinidae): Biocontrol Candidate Agents for White Peach Scale in Hawaii

Abstract

We genetically characterized Encarsia diapsidicola Silvestri and Encarsia berlesei Howard (Hymenoptera: Aphelinidae) by two molecular methods: phylogenetic analysis of the cytochrome oxidase subunit I gene (COI) and intersimple sequence repeat-polymerase chain reaction (ISSR-PCR) DNA fingerprinting. These two closely related endoparasitoids are candidate biological control agents for the white peach scale, Pseudaulacaspis pentagona Targioni-Tozetti (Hemiptera: Diaspididae), in Hawaii. We developed species-specific COI molecular markers that discriminated the two species, and we tested the utility of the E. diaspidicola-specific COI marker to detect parasitism of white peach scale. The COI sequence data uncovered 46-bp differences between the two Encarsia spp. The level of COI genetic divergence between the two species was 9.7%, and the two clustered into their own clade on a parismonious phylogram. ISSR-PCR readily discriminated the two Encarsia spp. because each was observed with fixed species-specific banding patterns. The COI molecular markers were specific for each species because cross-reactivity was not observed with nontarget species. The E. diaspidicola-specific COI markers were successful at detecting parasitism of white peach scale by E. diaspidicola by 24 h. Both molecular marker types successfully discriminated the two Encarsia spp., whereas the COI markers will be useful as tools to assess levels of parasitism in the field and to study competitive interactions between parasitoids.

A revision of the Encarsia pergandiella species complex (Hymenoptera: Aphelinidae) shows cryptic diversity in parasitoids of whitefly pests

“…Integrative taxonomy provides a practical framework for species delimitation by integrating molecular, morphological, morphometric, biological, ecological and behavioural data as independent lines of evidence (Dayrat, 2005;Chesters et al, 2012;Gebiola et al, 2012). The taxonomy and systematics of Encarsia have greatly benefited from the use of molecular markers, such as the expansion region D2 of the ribosomal gene 28S (Babcock & Heraty, 2000;Babcock et al, 2001;Manzari et al, 2002) and the mitochondrial gene cytochrome c oxidase subunit I (COI) (de León et al, 2010). However, the problem of genetically identifying cryptic species of Encarsia has been tackled only twice, using COI alone (Monti et al, 2005) or in combination with 28S-D2 (Gebiola et al, 2016).…”

Isolation and Characterization of Nine Microsatellite Loci for a Parasitoid Wasp, Encarsia smithi (Silvestri) (Hymenoptera: Aphelinidae)

“…This is the first report on the isolation of microsatellite loci in Encarsia species, with the exception of the use of ISSR-PCR in E. diaspidicola and E. berlesei [12]. The characterized microsatellite markers are well suited to estimate the genetic diversity of E. smithi populations and will improve the classical biological control of orange spiny whitefly and tea spiny whitefly using E. smithi .…”

Primary parasitoids of red scale (Aonidiella aurantii) in Australia and a review of their introductions from Asia

“…For the ITS region, the cycling conditions of de León et al . () were followed. For the 28S rRNA gene from the Aphytis and Encarsia species, the same thermocycling conditions as for CO I were used but with an annealing temperature of 50 °C.…”

“…For COI, the cycling parameters were: an initial denaturation for 5 min at 95°C; 33 cycles of 45 s at 95°C for denaturation, 90 s at 50°C (scale insects) or 58°C (parasitoids) for annealing, and 120 s at 72°C for extension; and a final extension of 5 min at 72°C. For the ITS region, the cycling conditions of de León et al (2010) were followed. For the 28S rRNA gene from the Aphytis and Encarsia species, the same thermocycling conditions as for COI were used but with an annealing temperature of 50°C.…”