Identification of major component of male-produced aggregation pheromone of larger grain borer,Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae)

Abstract

Male beetles of the larger grain borer,Prostephanus truncatus Horn (Coleoptera: Bostrichidae) were shown to produce material causing an electroantennographic (EAG) response from both male and female beetles. Volatiles from mixed sex cultures were collected on Porapak Q and fractionated by liquid chromatography (LC) with gradient elution. The total volatiles and the fractions were analyzed by gas chromatography (GC) linked to EAG, and two compounds eluting in the same LC fraction elicited EAG responses from male and female beetles. These were assumed to be components of the male-produced aggregation pheromone. Amounts of these compounds obtained were very low and less than 10(-3) times the amounts of the aggregation pheromone components produced by the related species,Rhyzopertha dominica, under similar conditions. The most abundant of these EAG-active compounds was identified as 1-methyiethyl (2E)-2-methyl-2-pentenoate by comparison of its GC retention times and mass spectrum with those of synthetic analogs. The synthetic compound elicited electrophysiological and behavioral responses in both male and female beetles significantly greater than those to structural analogs. This compound is attractive toP. truncatus beetles in the field, and has been given the trivial name of "trunc-call 1".

Flight initiation and flight activity in Prostephanus truncatus (Coleoptera: Bostrichidae)

“…Obeng-Ofori & Coaker, *Fax: 49511 762 3015 E-mail: scholz@mbox.ipp.uni-hannover.de 1990). The two main components of the pheromone have been identified (Cork et al, 1991), synthesized, and used to determine the beetle's spread and flight activity (Richter & Biliwa, 1991;Borgemeister et al, 1997). Studies in Kenya (Giles et al, 1995;Nang'ayo, 1996), Benin and Mexico (Tigar et al, 1994) showed strong seasonal fluctuations in the numbers of P. truncatus caught with pheromone-baited traps.…”

Trees or stores? The origin of migrating Prostephanus truncatus collected in different ecological habitats in southern Benin

“…Funnel traps, baited with the synthetic aggregation pheromone of P. truncatus [1 mg T1 and 1 mg T2; AgriSense-BCS Ltd., Pontypridd, UK; developed by the Natural Resource Institute, UK (NRI) (Cork et al, 1991)] were set up at three sites in different agro-ecological zones of Benin. Funnel traps, baited with the synthetic aggregation pheromone of P. truncatus [1 mg T1 and 1 mg T2; AgriSense-BCS Ltd., Pontypridd, UK; developed by the Natural Resource Institute, UK (NRI) (Cork et al, 1991)] were set up at three sites in different agro-ecological zones of Benin.…”

“…P. truncatus belongs to a family of principally wood-boring beetles (Freude et al, 1969). Trap data, using the synthetic aggregation pheromone of P. truncatus as bait (Dendy et al, 1989;Cork et al, 1991), revealed a high level of flight activity in forest habitats of Mexico (Rees et al, 1990), andKenya (Nang'ayo, 1996). Laboratory experiments showed that the beetle can reproduce on a wide variety of woody plant species (Nang'ayo et al, 1993;Nang'ayo, 1996).…”

Biorational Approaches to Managing Stored-Product Insects

“…Release and perhaps production of the pheromones by males is closely tied to feeding or contact with food: Males locate food, produce pheromones, attract females and other males, and mate; females oviposit at that site, where larvae ultimately develop. Aggregation pheromone systems have been described for stored-product pests in the families Bostrichidae (20,24), Curculionidae (86,122), Cucujidae and Silvanidae (76), and Tenebrionidae (46,106). Pheromones provide highly sensitive tools for insect detection, because a pheromone trap may detect the presence of an insect while numerous traditional samples would detect none, and pheromones are highly specific to a target species.…”