Biodiversity Data Journal :
Taxonomic Paper
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Corresponding author: Rammohan R Balusu (balusrr@auburn.edu)
Academic editor: Jose Fernandez-Triana
Received: 19 Aug 2019 | Accepted: 24 Sep 2019 | Published: 28 Oct 2019
This is an open access article distributed under the terms of the CC0 Public Domain Dedication.
Citation:
Balusu RR, Talamas EJ, Cottrell TE, Toews MD, Blaauw BR, Sial AA, Buntin DG, Fadamiro HY, Tillman G (2019) First record of Trissolcus basalis (Hymenoptera: Scelionidae) parasitizing Halyomorpha halys (Hemiptera: Pentatomidae) in the United States. Biodiversity Data Journal 7: e39247. https://doi.org/10.3897/BDJ.7.e39247
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A parasitoid wasp, Trissolcus basalis (Wollaston), was recorded parasitizing eggs of the invasive stink bug Halyomorpha halys (Stål) in the United States. This is the first record of this species parasitizing fresh and frozen eggs of H. halys in the United States.
First record of Trissolcus basalis parasitizing Halyomorpha halys eggs in the United States.
Parasitoid wasp, endoparasitoid, brown marmorated stink bug
The brown marmorated stink bug, Halyomorpha halys (Stål), 1855 (Hemiptera: Pentatomidae) (BMSB) is a native of China, Taiwan, South Korea and Japan. Unfortunately, this invasive insect pest has spread to the United States (
In the south-eastern U.S., populations of H. halys are continuing to expand into the Piedmont and Coastal Plains regions of Georgia and Alabama. Halyomorpha halys was first detected in Alabama in 2010. One year later, urban pest management professionals began reporting overwintering brown marmorated stink bugs in homes in the metropolitan Atlanta area. Currently, the brown marmorated stink bug threatens peaches, plums, blueberries, apples, wine grapes, kiwifruit, soybean, cotton, pecan and tomatoes in both states. The tree of heaven, Ailanthus altissima (Mill.) Swingle, a tree with seed pods that are a favourite non-crop food source for H. halys, also occurs in both states.
Presently, 18 species of hymenopteran endoparasitoids in the genera Anastatus Motchulsky (Eupelmidae), Trissolcus Ashmead, Telenomus Haliday and Gryon Haliday (Scelionidae) have been reported to parasitize eggs of H. halys in the U.S. (
Laboratory-reared H. halys egg masses were laid on knit cloth (97% cotton, 3% spandex). On 24 June 2018, 30 fresh egg masses (≤ 24 h old) were hung as sentinels on tomato plants for 72 h. Some egg masses (≤ 12 h old) were frozen and held at -20ºC for 1–4 d. On 18 October, 30 frozen egg masses were hung as sentinels on plants in cotton and soybean for 72 h. In the laboratory, the collected egg masses were held for emergence of adult parasitoids and emergent wasps were identified using the key of
All egg masses were dissected for dead, immature parasitoids. Determination of T. basalis immature stages, mainly third instars, prepupae and pupae, were based on descriptions of T. basalis immatures in
Two dried point-mounted specimens were selected for DNA extraction and mitochondrial cytochrome c oxidase I (COI) fragment sequencing. Specimens were softened in 70% ethanol for two hours, then DNA was extracted using a DNeasy Blood and Tissue Kit (Qiagen). The DNA samples were quantified using a NanoDrop 2000 spectrophotometer (Thermo Scientific). At least 20 ng of genomic DNA was used per PCR. The 5’-COI region was PCR-amplified using the primers LCO1490 and HCO2198 (
Trissolcus basalis can be identified from Nearctic congeners by the combination of the following characters: vertex without hyperoccipal carina, netrion sulcus incomplete, mesopleuron with episternal foveae shallowly impressed, metapleuron without setation and without well-defined paracoxal sulcus; T2 striate (Figs
Trissolcus basalis is found worldwide (http://hol.osu.edu/map-large.html?id=3189).
At the Tuscaloosa site, T. basalis parasitised four of the 30 sentinel egg masses; at the other two sites, only one of the 30 egg masses was parasitised by T. basalis. Overall, percent parasitism per egg mass was moderately high (62.7%). In general, percent immature mortality was slightly higher for frozen egg masses (48.2%) than for fresh ones (35.4%). Overall, 38.0% of the parasitoids emerged as adults. A female biased sex ratio of 4F:1M was observed for emergent parasitoids.
Additional host associations of T. basalis, provided by
The CO1 sequences of the two specimens were identical to each other and to the 7 CO1 sequences of T. basalis in Genbank. These sequences derive from specimens collected in Italy, Japan and the United States and their invariance indicates that this gene is not informative for identifying populations within the species.
Multiple species of Trissolcus are known to oviposit into the eggs of H. halys despite a physiological inability to develop in them, creating an evolutionary trap (
This work was supported by Specialty Crop Research Initiative, award number 2016-51181-25409 from the USDA National Institute of Food and Agriculture, the USDA Farm Bill Identification, monitoring & redistribution of Trissolcus japonicus: Biological Control of Brown Marmorated Stink Bug, the Florida Department of Agriculture and Consumer Services Division of Plant Industry, the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2018-700006-27172 and the Alabama Agricultural Experiment Station (Auburn University). The authors appreciate excellent technical support from Kristie Graham, Merry Bacon, Rebekah Hartley (USDA, ARS), Sarah Hobby, Sriyanka Lahiri, Brian Little, Jordan Breedlove (University of Georgia) and Matthew Moore and Cheryl Roberts who performed the PCR and sequencing (FDACS/DPI).