Molecular markers discriminate closely related species Encarsia diaspidicola and Encarsia berlesei (Hymenoptera: Aphelinidae): biocontrol candidate agents for white peach scale in Hawaii

Immune Gene Repertoire of Soft Scale Insects (Hemiptera: Coccidae)

Insects possess an effective immune system, which has been extensively characterized in several model species, revealing a plethora of conserved genes involved in recognition, signaling, and responses to pathogens and parasites. However, some taxonomic groups, characterized by peculiar trophic niches, such as plant-sap feeders, which are often important pests of crops and forestry ecosystems, have been largely overlooked regarding their immune gene repertoire. Here we annotated the immune genes of soft scale insects (Hemiptera: Coccidae) for which omics data are publicly available. By using immune genes of aphids and Drosophila to query the genome of Ericerus pela, as well as the transcriptomes of Ceroplastes cirripediformis and Coccus sp., we highlight the lack of peptidoglycan recognition proteins, galectins, thaumatins, and antimicrobial peptides in Coccidae. This work contributes to expanding our knowledge about the evolutionary trajectories of immune genes and offers a list of promising candidates for developing new control strategies based on the suppression of pests' immunity through RNAi technologies.

Natural enemies of armored scales (Hemiptera: Diaspididae) and soft scales (Hemiptera: Coccidae) in Chile: Molecular and morphological identification

Scale insects (Hemiptera: Sternorrhyncha: Coccomorpha) are key pests of agricultural crops and ornamental plants worldwide. Their populations are difficult to control, even with insecticides, due to their cryptic habits. Moreover, there is growing concern over the use of synthetic pesticides for their control, due to deleterious environmental effects and the emergence of resistant populations of target pests. In this context, biological control may be an effective and sustainable approach. Hymenoptera Chalcidoidea includes natural enemies of scale insects that have been successfully used in many biological control programs. However, the correct identification of pest scale species and their natural enemies is particularly challenging because these insects are very small and highly specialized. Integrative taxonomy, coupling DNA barcoding and morphological analysis, has been successfully used to characterize pests and natural enemy species. In this study, we performed a survey of parasitoids and predators of armored and soft scales in Chile, based on 28S and COI barcodes. Fifty-three populations of Diaspididae and 79 populations of Coccidae were sampled over the entire length of the country, from Arica (18°S) to Frutillar (41°S), between January 2015 and February 2016. The phylogenetic relationships obtained by Bayesian inference from multilocus haplotypes revealed 41 putative species of Chalcidoidea, five Coccinellidae and three Neuroptera. Species delimitation was confirmed using ABGD, GMYC and PTP model. In Chalcidoidea, 23 species were identified morphologically, resulting in new COI barcodes for 12 species and new 28S barcodes for 14 species. Two predator species (Rhyzobius lophantae and Coccidophilus transandinus) were identified morphologically, and two parasitoid species, Chartocerus niger and Signiphora bifasciata, were recorded for the first time in Chile.

Molecular Characterization of the Indigenous Stingless Bees (Tetragonula spp. Complex) Using ISSR Marker from Southern Peninsular India

India is a country bestowed enormously with stingless bees, but genetic information about them is extremely minimal. This study focused to tap the geographic allocation, genetic variability, and differentiation among Tetragonula species complexes from natural and semi-urban habitats. Genetic analyses were assessed among 36 contrasting genotypes utilizing 20 ISSR primers. The dual combination exquisitely and productively amplified 245 DNA fragments at the loci, of which 240 bands were polymorphic (97.95%). Low to moderate level of genetic differentiation was detected from different estimators (Ht 0.29, G' _STest 0.16, D _est 0.072, F _ST 0.14, and Nm 2.68). Hierarchical clustering analysis aided to partition the individual genotypes into its respective five species group formed, aided by substantial bootstrap support values, but differing under morphological identification. It also provided valuable insight into the moderate eco-genetic diversity (H 0.39) prevailing from geographically scattered inhabitants. Potential exploitation of hyper-variable ISSR marker turned out fairly as a promising technique for finding valid polymorphisms and infers relevant variations. This baseline information enhances our understanding of the genetic status of the indigenous species from the country.

Molecular evidence for multiple phylogenetic groups within two species of invasive spiny whiteflies and their parasitoid wasp

The invasive orange spiny whitefly (OSW) Aleurocanthus spiniferus has extended its distribution to non-native areas since the early 20th century. In a similar manner, the invasive tea spiny whitefly (TSW) A. camelliae has been expanding over East Asia in recent decades. In this study, the genetic diversity of OSW and TSW and of their important parasitoid wasp Encarsia smithi was investigated in China and Japan to enable more efficient biological control policies. We detected two phylogenetic groups (haplogroups A1 and A2) in OSW and three phylogenetic groups (haplotypes B1 and B2, and haplogroup B3) in TSW in China; however, only a single haplotype was detected in each whitefly species in Japan. Based on historical records and molecular data, OSW was considered to be native to China whereas TSW has probably expanded to China from a more southern location in the last 50 years; China appears to be the source region for OSW and TSW invading Japan. In E. smithi, two phylogenetic groups were detected in Japan: haplotype I, associated with OSW, and haplogroup II mostly associated with TSW, except in two locations. These data support the hypothesis that E. smithi parasitizing TSW in Japan did not originate from the existent population parasitizing OSW but was newly imported into Japan following the invasion of its host.

Molecular Markers Detect Cryptic Predation on Coffee Berry Borer (Coleoptera: Curculionidae) by Silvanid and Laemophloeid Flat Bark Beetles (Coleoptera: Silvanidae, Laemophloeidae) in Coffee Beans

The coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae), is a serious pest of coffee worldwide. It was first detected in Hawai'i in 2010. Two predatory beetles, Cathartus quadricollis (Coleoptera: Silvanidae) and Leptophloeus sp. (Coleoptera: Laemophloeidae), have been observed in H. hampei-infested coffee. Under laboratory conditions, colony-reared C. quadricollis and Leptophloeus sp. prey upon all life stages of H. hampei. However, the H. hampei life cycle occurs almost exclusively within a coffee bean obscured from direct observation. Thus, it is unknown if C. quadricollis and Leptophloeus sp. consume H. hampei as prey in the wild. To demonstrate predation of H. hampei by C. quadricollis and Leptophloeus sp., a molecular assay was developed utilizing species-specific primers targeting short regions of the mitochondrial COI gene to determine species presence. Using these primers, wild C. quadricollis and Leptophloeus sp. were collected and screened for the presence of H. hampei DNA using PCR. Analysis of collections from five coffee farms revealed predation of C. quadricollis and Leptophloeus sp. on H. hampei. Further laboratory testing showed that H. hampei DNA could be detected in predators for as long as 48 h after feeding, indicating the farm-caught predators had preyed on H. hampei within 2 d of sampling. This study demonstrates the utility of molecular markers for the study of the ecology of predators and prey with cryptic behavior, and suggests C. quadricollis and Leptophloeus sp. might be useful biocontrol agents against H. hampei.

Isolation and characterization of nine microsatellite loci for a parasitoid wasp, Encarsia smithi (Silvestri) (Hymenoptera: Aphelinidae)

The parasitoid wasp Encarsia smithi is an important agent in the classical biological control of two species of invasive spiny whiteflies, Aleurocanthus spiniferus and Aleurocanthus camelliae. To evaluate the performance of parasitism indexed by genetic diversity, a highly polymorphic genetic marker is required. In this report, nine microsatellite loci are described for E. smithi. The microsatellite loci were obtained through the construction of an enriched library and exhibited polymorphisms (2–6 alleles per locus) and high levels of expected heterozygosities (0.203–0.780, average 0.537). Linkage disequilibrium and null alleles were not detected in these microsatellite loci. The isolated microsatellite markers may be useful to estimate the genetic diversity of E. smithi.