Michael W. Gates

Model of Cryptolestes ferrugineus Flight Activity Outside Commercial Steel Grain Bins in Central Oklahoma

Abstract Unbaited sticky traps were placed on ropes in the four cardinal directions and at different heights on the outside of commercial steel bins containing stored wheat. Weekly trap catches of the rusty grain beetle, Cryptolestes ferrugineus (Stephens), were examined. The number of traps per steel bin varied due to differences in dimensions, and three height classes were established, but there was no significant difference in trap catches of C. ferrugineus among height classes. Significant yearly and between-steel bin variation was found, and these effects were removed before using a response surface regression analysis to determine how well two time variables (daylength and day number) and three weather variables (minimum and maximum temperature and precipitation) could explain the seasonal variation in C. ferrugineus flight activity. These variables were used in separate analyses of C. ferrugineus trap catches in the four cardinal directions and from the three height classes (12 separate analyses). The most robust model fit was obtained when using a subset representing 208 C. ferrugineus trap catches from the northern side at height class 3 (traps s placed at least three-quarters of bin height). The full model of the two time variables and three weather variables explained 48% of the variance in this subset of trap catches, whereas a model based on weekly means of daylength and minimum and maximum air temperatures explained 40% of the total variance in C. ferrugineus trap catches. The relative trap catch response to daylength and minimum and maximum air temperatures was evaluated. High beetle flight activity around grain bins may indicate a high risk of insect infestation of stored wheat, and the presented model can therefore be used to determine time periods with high risk of beetle immigration into commercial steel bins.

A New Species of Oobius Trjapitzin (Hymenoptera: Encyrtidae) From the Russian Far East That Parasitizes Eggs of Emerald Ash Borer (Coleoptera: Buprestidae)

Abstract We describe a new species of egg parasitoid, Oobius primorskyensis Yao & Duan n. sp., collected from the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) near Vladivostok, Russia. Morphological and molecular analyses indicate that this taxon is sufficiently distinct from Oobius agrili Zhang & Huang 2005 to merit species status. Furthermore, DNA sequence divergence between O. primorskyensis and specimens in culture of Chinese origin suggest that O. primorskyensis is molecularly distinct from Oobius previously imported into the United Stated and released as biological control agents of emerald ash borer. Laboratory observations showed that O. primorskyensis also differs from O. agrili in diapause pattern. When reared with A. planipennis eggs at 25 ± 1.5° C, 65 ± 10% relative humidity, and a photoperiod of 16:8 (L:D) h, nearly 100% of O. primorskyensis diapaused at the second and third generations after their parents had diapaused, whereas a majority (60–96%) of O. agrili did not diapauses for 11 sequential generations. Diagnosis of the species with respect to O. agrili is provided. The new species is a natural enemy of A. planipennis in its native range and may be considered for introduction against A. planipennis in North America.

Description of Camponotophilus delvarei, gen. n. and sp. n. (Hymenoptera: Chalcidoidea: Eurytomidae), with Discussion of Diagnostic Characters

Abstract. The new genus Camponotophilus Gates is described, and characters of phylogenetic, diagnostic, and myrmecophilic importance are discussed. Camponotophilus delvarei Gates, new species is described. This is the first report of myrmecophily in Eurytomidae, and a discussion of morphological trends in myrmecophilic parasitic Hymenoptera is provided.

Parasitoids Attacking Larvae of a Recently Introduced Weed Biological Control Agent, Neomusotima conspurcatalis (Lepidoptera: Crambidae): Key to Species, Natural History, and Integrative Taxonomy

ABSTRACT The extent to which introduced weed biocontrol agents are subject to attack by generalist natural enemies within the area of introduction is believed to be an important determinant of program success. We monitored larval populations of a recently introduced weed biocontrol agent, Neomusotima conspurcatalis Warren, at field sites in Florida to investigate parasitism by native parasitoids and to assess the overall rate of parasitism. Of six native parasitoid species reared from wild larvae of N. conspurcatalis, five, Rhygoplitis choreuti (Viereck), Stantonia pallida (Ashmead), Elasmus apanteli Gahan, Hyphantrophaga sellersi (Sabrosky), and an unidentified Cotesia sp. were primary parasitoids of the biocontrol agent. The sixth species, Mesochorus apantelis Dasch, is likely a hyperparasitoid of R. choreuti. From 1,100 N. conspurcatalis larvae collected from three sites, adult parasitoids emerged from 6.8% of those larvae and 73.6% of the N. conspurcatalis developed to adulthood. R. choreuti was the most common parasitoid, accounting for 81% of adults reared. Photographs of parasitoid species are provided, aspects of their natural histories and host ranges are described, and accumulation of native parasitoids on introduced weed biocontrol agents is discussed.

Impact of the Egg Parasitoid, Gryon pennsylvanicum (Hymenoptera: Scelionidae), on Sentinel and Wild Egg Masses of the Squash Bug (Hemiptera: Coreidae) in Maryland.

Abstract Seasonal changes in egg parasitism and predation rates on sentinel (laboratory-reared) and wild (naturally occurring) egg masses of the squash bug, Anasa tristis (De Geer), were evaluated in squash fields in Maryland from June through September in 2013 and 2014. Rates of egg parasitism were significantly higher on wild egg masses than on sentinel egg masses. Squash bug nymphal emergence was significantly higher on sentinel egg masses than on wild egg masses. Between the first week of July and the first week of September of both survey years, squash bug nymphs emerged from 24.2% of wild eggs compared with 46.2% of sentinel eggs and parasitoids emerged from 55.7% of wild eggs compared with only 21.8% of sentinel eggs. Sentinel egg masses significantly underestimated the rate of natural egg parasitism. The egg parasitoid, Gryon pennsylvanicum (Ashmead), was responsible for over 99% of parasitism of squash bug eggs. There was a significant negative correlation between parasitoid emergence and nymphal emergence, suggesting that parasitoids were able to suppress squash bug populations. The average rate of parasitoid emergence peaked on wild egg masses on the fifth week of July at 72.8%, whereas the average rate of nymphal emergence from wild egg masses was <20% from the fifth week of July until the first week of September. These results demonstrate that G. pennsylvanicum was able to efficiently track wild squash bug eggs throughout the season and that it has the potential to be an effective biological control agent of the squash bug in Maryland.

Phylogenomic Analysis of Ants, Bees and Stinging Wasps: Improved Taxon Sampling Enhances Understanding of Hymenopteran Evolution

The importance of taxon sampling in phylogenetic accuracy is a topic of active debate. We investigated the role of taxon sampling in causing incongruent results between two recent phylogenomic studies of stinging wasps (Hymenoptera: Aculeata), a diverse lineage that includes ants, bees and the majority of eusocial insects. Using target enrichment of ultraconserved element (UCE) loci, we assembled the largest aculeate phylogenomic data set to date, sampling 854 loci from 187 taxa, including 30 out of 31 aculeate families, and a diversity of parasitoid outgroups. We analyzed the complete matrix using multiple analytical approaches, and also performed a series of taxon inclusion/exclusion experiments, in which we analyzed taxon sets identical to and slightly modified from the previous phylogenomic studies. Our results provide a highly supported phylogeny for virtually all aculeate lineages sampled, supporting ants as sister to Apoidea (bees+apoid wasps), bees as sister to Philanthinae+Pemphredoninae (lineages within a paraphyletic Crabronidae), Melittidae as sister to remaining bees, and paraphyly of cuckoo wasps (Chrysidoidea). Our divergence dating analyses estimate ages for aculeate lineages in close concordance with the fossil record. Our analyses also demonstrate that outgroup choice and taxon evenness can fundamentally impact topology and clade support in phylogenomic inference.

Two new species of Oobius Trjapitzin (Hymenoptera, Encyrtidae) egg parasitoids of Agrilus spp. (Coleoptera, Buprestidae) from the USA, including a key and taxonomic notes on other congeneric Nearctic taxa.

Abstract Oobius Trjapitzin (Hymenoptera, Encyrtidae) species are egg parasitoids that are important for the biological control of some Buprestidae and Cerambycidae (Coleoptera). Two species, Oobius agrili Zhang & Huang and Oobius longoi (Siscaro), were introduced into North America for classical biocontrol and have successfully established. Two new native North American species that parasitize eggs of Agrilus spp. (Buprestidae) are described and illustrated from the USA: Oobius minusculus Triapitsyn & Petrice, sp. n. (Michigan), an egg parasitoid of both Agrilus subcinctus Gory on ash (Fraxinus spp.) and Agrilus egenus Gory on black locust (Robinia pseudoacacia L.) trees, and Oobius whiteorum Triapitsyn, sp. n. (Pennsylvania), an egg parasitoid of Agrilus anxius Gory on European white birch (Betula pendula Roth). A taxonomic key and notes on the Nearctic native and introduced Oobius species are also included.

Relationship Between Flight Activity Outside Grain Bins and Probe Trap Catches Inside Grain Bins of Cryptolestes Ferrugineus

Abstract Insect sampling/monitoring inside grain bins is time consuming, cumbersome during the summer heat in the headspace of grain bins, may require investment in costly sampling devices for sampling of grain, and involves a certain risk to employees. Thus, it is important to explore unbaited sticky traps on the outside of grain elevators as decision support tools for improved management of stored grain. In this study, we analyzed seven trap catch data sets of unbaited sticky trap catches on the outside of grain bins and corresponding probe trap catches in the upper level of the grain mass at three farm bins in 1991, with capacities ranging from 68 to 141 metric tons, and at two commercial steel bins in 1993 and 1994, with capacities of 5,400 and 6,800 metric tons. We used response surface regression analysis to analyze standardized trap catches of the rusty grain beetle, Cryptolestes ferrugineus, and showed that (1) from late June to late July, catches on unbaited sticky traps placed on the outside of grain bins preceded probe traps inside the bins by ≈3 d, which suggested immigration into bins; and (2) in late August, unbaited sticky trap catches on the outside of bins started to decrease, while probe trap catches inside the bins continued to increase until mid-September. We concluded that, from late June to mid-August, immigration of C. ferrugineus individuals into grain bins influences abundance in the upper grain layer, whereas later in the season, the two types of trap catches were only loosely associated. This study is consistent with results published elsewhere that immigration of C. ferrugineus into grain bins initiated shortly after wheat was loaded into the bins.

New Host Record for Camponotophilus delvarei (Hymenoptera: Eurytomidae), a Parasitoid of Microdontine Larvae (Diptera: Syrphidae), Associated with the Ant Camponotus sp. aff. textor

Microdontine syrphid flies are obligate social parasites of ants. Larvae prey on ant brood whereas adults live outside the nests. Knowledge of their interaction with their host is often scarce, as it is information about their natural enemies. Here we report the first case of parasitism of a species of microdontine fly by a myrmecophilous eurytomid wasp. This is also the first host record for Camponotophilus delvarei Gates, a recently described parasitic wasp discovered in Chiapas, Mexico, within the nests of the weaver ant, Camponotus sp. aff. textor Forel. Eleven pupal cases of a microdontine fly were found within a single nest of this ant, five of them being parasitized. Five adult C. delvarei females were reared from a puparium and 29 female and 2 male pupae were obtained from another one. The eurytomid is a gregarious, primary ectoparasitoid of larvae and pupae of Microdontinae, its immature stages developing within the protective puparium of the fly. The species is synovigenic. Adult females likely locate and parasitize their hosts within the ant nest. As some species of Microdontinae are considered endangered, their parasitoids are likewise threatened and in need of accurate and urgent surveys in the future.

First report of an egg parasitoid reared from Neomusotima conspurcatalis (Lepidoptera: Crambidae), a biological control agent of Lygodium microphyllum (Schizaeales: Lygodiaceae)

Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae) was first released in Florida, USA, as a biological control agent of Lygodium microphyllum (Cavanilles) R. Brown (Schizaeales: Lygodiaceae), Old World climbing fern, in 2008. The first egg parasitoid, a Trichogramma sp. (Hymenoptera: Trichogrammatidae), was reared from N. conspurcatalis in 2013. The parasitoid is widely distributed in south Florida, where its egg mass parasitism rates can reach 100%. Sumario Neomusotima conspurcatalis Warren (Lepidoptera: Crambidae) fue liberado por primera vez en la Florida, EE.UU., como un agente de control biologico de Lygodium microphyllum (Cavanilles) R. Brown (Polypodiales: Lygodiaceae), el helecho trepador del Viejo Mundo, en 2008. El primer parasitoide de huevos, un Trichogramma sp., fue criadocriado de N. conspurcatalis en 2013. El parasitoide se distribuye ampliamente en el sur de Florida, donde sus tasas de parasitismo de masas de huevos pueden llegar al 100%. View this article in BioOne