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Elkton, MD, United States

Hrabar M.,Simon Fraser University | Zhai H.,Simon Fraser University | Gries R.,Simon Fraser University | Schaefer P.W.,4 Dare Drive | And 3 more authors.
Journal of Chemical Ecology | Year: 2015

Xenos peckii is a strepsipteran parasitoid of the common North American paper wasp, Polistes fuscatus. Mate-seeking X. peckii males respond to a long-range sex pheromone emitted by the female, which remains permanently embedded within the abdomen of a mobile host wasp. During peak pheromone signalling, we excised the female from her host, severed the cephalothorax containing the pheromone gland, extracted it in hexane, and analyzed aliquots of combined extracts by coupled gas chromatographic-electroantennographic detection (GC-EAD). These analyses revealed a candidate pheromone component (CPC) that consistently elicited strong responses from male antennae. We identified the CPC as (7E,11E)-3,5,9,11-tetramethyltridecadienal based on its retention indices (RI) on three GC-columns, RI inter-column differentials, mass and NMR spectra, and synthesis of an authentic standard that matched the GC-retention and spectrometric characteristics of the CPC. For a field experiment, we prepared (7E,11E)-3,5,9R,11-tetramethyltridecadienal and (7E,11E)-3,5,9S,11-tetramethyltridecadienal. Xenos peckii males were caught in traps baited with either compound singly or a 1:1 mixture of the two but not in unbaited control traps. The sex pheromone of X. peckii resembles that reported for the strepsipterans Stylops mellittae and S. muelleri, (R,R,R)-3,5,9-trimethyldodecanal, suggesting a common biosynthetic pathway across taxonomic genera. © 2015, Springer Science+Business Media New York.

Hrabar M.,Simon Fraser University | Danci A.,Simon Fraser University | McCann S.,Simon Fraser University | Schaefer P.W.,4 Dare Drive | Gries G.,Simon Fraser University
Canadian Entomologist | Year: 2014

We studied life history traits of Xenos peckii Kirby (Strepsiptera: Xenidae), a little-known parasite of the paper wasp Polistes fuscatus (Fabricus) (Hymenoptera: Vespidae) in North America. We field-collected 24 wasp nests in early July 2012, isolated parasitised wasps, tracked life history events of X. peckii, and recorded such behaviour as emergence of males and mating by normal-speed and high-speed cinematography. To emerge, males first cut the puparium with their mandibles along an ecdysial suture line, and then push aside the pupal cap during emergence. The endoparasitic females engage in active calling (pheromone release) behaviour by slowly inflating their cephalothorax, and then extruding it even farther out of, and tilting it away from, the host wasp abdomen. Seasonal and diel (afternoon) emergence periods of males coincide with seasonal and diel receptivity and calling periods of females. Males approach calling females in a swaying flight with smooth turns. They typically land on the anterior portion of the host wasp's abdomen, and then step backward until they make contact with the cephalothorax of the female. As soon as their mesothoracic legs contact the female's cephalothorax, they curl around it, and the male initiates mating. Thereafter, the female fully retreats and never re-mates. Copyright © Entomological Society of Canada 2014 Â.

Danci A.,Simon Fraser University | Hrabar M.,Simon Fraser University | Ikoma S.,Simon Fraser University | Schaefer P.W.,4 Dare Drive | Gries G.,Simon Fraser University
Entomologia Experimentalis et Applicata | Year: 2013

The ability of insects to learn locations of future resources has rarely been studied. Here, we show that males of the solitary parasitoid wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae) learn locations of future mates. Male P. disparis reportedly arrest on parasitized pupae of wax moth, Galleria mellonella L. (Lepidoptera: Pyralidae), and gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae), when mate emergence is imminent. We tested the hypothesis that male P. disparis identify, memorize, and revisit the location(s) of parasitized host pupae as a strategy to attain mates. We colour-coded P. disparis males in the field and noticed that they revisit parasitized moth pupae on consecutive days, and arrest on those pupae with a near-emergence P. disparis parasitoid. In a laboratory experiment with two large corrugated cardboard cylinders (CCCs) as surrogate trees, each CCC bearing two parasitized moth pupae with a near-emergence P. disparis parasitoid or two pupae not parasitized, males on day 1 of the experiment visited parasitized pupae more often than pupae not parasitized. On day 2, when each CCC had been replaced and now carried pupae that were not parasitized, males returned to the same CCC, or the same micro-location on that CCC, which on day 1 had carried parasitized pupae. Field and laboratory data combined indicate that male P. disparis learn the location of future mates. With female P. disparis being haplodiploid and capable of reproducing without mating experience, the onus to find a mate is on males. They accomplish this by detecting parasitized pupae, learning their location, revisiting them frequently, and then arresting on them when the prospective mate nears emergence, taking a 50% chance that it is indeed a female. © 2013 The Netherlands Entomological Society.

Lymantria (Lymantria) lucescens (Butler) collections and observations were made at Toyota and Azumino, Honshu, Japan. Larvae are now recorded to feed on Fagaceae (Quercus, four species); Ulmaceae (Ulmus and Zelkova) and Moraceae (Morus). During the moth flight (July in Toyota), both sexes (but only 15% females) were attracted to commercial lighting and settled on lit surfaces such as storefronts. Females (wingspan av. 72 mm) carried on average 758 eggs each. Periodicity of male moths responding to either synthetic sex pheromone or to visible lights showed that flight activity peaked between 2000 and 2100 h. Three different larval parasitoids from L. lucescens were recovered. L. lucescens is discussed in light of attributes favoring its potential invasiveness.

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