Reproductive arrest and stress resistance in winter-acclimated Drosophila suzukii.

Overwintering insects must survive the multiple-stress environment of winter, which includes low temperatures, reduced food and water availability, and cold-active pathogens. Many insects overwinter in diapause, a developmental arrest associated with high stress tolerance. Drosophila suzukii (Diptera: Drosophilidae), spotted wing drosophila, is an invasive agricultural pest worldwide. Its ability to overwinter and therefore establish in temperate regions could have severe implications for fruit crop industries. We demonstrate here that laboratory populations of Canadian D. suzukii larvae reared under short-day, low temperature, conditions develop into dark \u27winter morph\u27 adults similar to those reported globally from field captures, and observed by us in southern Ontario, Canada. These winter-acclimated adults have delayed reproductive maturity, enhanced cold tolerance, and can remain active at low temperatures, although they do not have the increased desiccation tolerance or survival of fungal pathogen challenges that might be expected from a more heavily melanised cuticle. Winter-acclimated female D. suzukii have underdeveloped ovaries and altered transcript levels of several genes associated with reproduction and stress. While superficially indicative of reproductive diapause, the delayed reproductive maturity of winter-acclimated D. suzukii appears to be temperature-dependent, not regulated by photoperiod, and is thus unlikely to be \u27true\u27 diapause. The traits of this \u27winter morph\u27, however, likely facilitate overwintering in southern Canada, and have probably contributed to the global success of this fly as an invasive species

Evidence of established brown marmorated stink bug populations in British Columbia, Canada

We report four new detections of invasive agricultural pest Halyomorpha halys (Stål) (Hempitera: Pentatomidae), the brown marmorated stink bug, in the Lower Mainland and Okanagan Valley regions of British Columbia (BC), Canada, in 2015 and 2016. These finds include two confirmed breeding populations, as well as homeowner collections at the same residence in two consecutive years. Preliminary comparisons of mitochondrial DNA haplotypes from these collections suggest that H. halys populations in BC are the result of movement and spread of existing populations in North America, likely from the Pacific Northwest USA

Diversity and distribution of cytochrome oxidase I (COI) haplotypes of the brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera, Pentatomidae), along the eastern front of its invasive range in Eurasia

The arrival, establishment and pest status of Halyomorpha halys in Europe and non-native countries in Asia have been well-documented, with thorough characterisation of the genetic diversity and occurrence of cytochrome oxidase I (COI) haplotypes in Switzerland, France, Hungary, Italy and Greece. However, a number of gaps exist in terms of the characterisation of the haplotype diversity and occurrence of H. halys along the invasion front that covers eastern Europe, western and central Asia. To contribute towards filling this gap, the COI haplotype diversity and distribution were investigated for H. halys collected in Serbia, Ukraine, Russia, Georgia and Kazakhstan. A total of 646 specimens were analysed and five haplotypes were found (H1, H3, H8, H33 and H80). Haplotype H1 was present in all five countries investigated and was the only haplotype detected amongst > 500 specimens collected from Ukraine, Russia and Georgia. H1 (82%) was the dominant haplotype found in Kazakhstan, alongside H3 (18%). In contrast to the low or no diversity observed in these four countries, Serbia had higher haplotype diversity and was represented by five haplotypes. Although H3 was dominant (47%) in Serbia, H1 was also prevalent (40%); the remaining haplotypes (H8, H33 and H80) were minor contributors (1–11%) to the haplotype composition. The results are discussed in context with other known populations in neighbouring countries and patterns of haplotype diversity indicate the movement of successful invasive populations in Europe to generate secondary invasions along the eastern front of the invasion in Eurasia. Possible scenarios regarding the spread of particular haplotypes in these regions are discussed, along with suggestions for future research to fill existing gaps

Alignment of COI barcode sequences for Trissolcus spp. (Hymenoptera: Scelionidae)

Alignment of sequences for the DNA barcoding region of the COI gene for species of Trissolcus collected in the field in Canada, Switzerland, and China. Alignment was performed in MegAlign (DNASTAR Lasergene) using ClustalW. BOLD Sequence ID number and Genus name provided for each specimen

Data from: A molecular diagnostic tool for the preliminary assessment of host-parasitoid associations in biological control programmes for a new invasive pest

Evaluation of host-parasitoid associations can be tenuous using conventional methods. Molecular techniques are well-placed to identify trophic links and resolve host-parasitoid associations. Establishment of the highly invasive Brown Marmorated Stink Bug, Halyomorpha halys (Hemiptera: Pentatomidae) outside Asia has prompted interest in the use of egg parasitoids (Hymenoptera: Scelionidae) as biological control agents. However, little is known regarding their host ranges. To address this, a DNA barcoding approach was taken wherein general PCR primers for Scelionidae and Pentatomidae were developed to amplify and sequence >500-bp products within the DNA barcoding region of the Cytochrome Oxidase I (COI) gene that would permit identification of key players in this association. Amplification of DNA from Pentatomidae and Scelionidae was consistent across a broad range of taxa within these families, and permitted detection of Scelionidae eggs within H. halys 1h following oviposition. In laboratory assays, amplification and sequencing of DNA from empty, parasitized eggs was successful for both host (100% success) and parasitoid (50% success). When applied to field-collected, empty egg masses the primers permitted host identification in 50 – 100% of the eggs analyzed, and yielded species-level identifications. Parasitoid identification success ranged from 33 – 67% among field-collected eggs, with genus-level identification for most specimens. The inability to obtain species-level identities for these individuals is due to the lack of coverage of this taxonomic group in public DNA sequence databases; this situation is likely to improve as more species are sequenced and recorded in these databases. These primers were able to detect and identify both pentatomid host and scelionid parasitoid in a hyperparasitized egg mass, thereby clarifying trophic links otherwise unresolved by conventional methodology

in silico testing of primers for Scelionidae and Pentatomidae

Output for in silico testing of Scel_F1, PENT_F2, HCO-2198 on Scelionidae, Telenomus, Trissolcus, and Pentatomidae consensus sequences. Results generated using FastPCR v6.4 (Kalendar et al. 2011; http://primerdigital.com/fastpcr.html) to screen target sequences to determine primer location, orientation, efficiency of binding, and complementarity

Alignment of public sequences for the COI gene for the Scelionidae

Alignment of public sequences available on the Barcode of Life Datasystems (BOLD) for the DNA barcoding region of the COI gene for the Scelionidae. Alignment was performed in MegAlign (DNASTAR Lasergene) using ClustalW. BOLD Sequence ID number and Genus name provided for each specimen

Primer Picking Results for Scelionidae

Location, direction, suitability, and amplification parameters for primers designed to amplify Scelionidae. Primer stats generated using Primer3 v0.4.0 (Untergrasser et al. 2012; http://bioinfo.ut.ee/primer3-0.4.0/)