RESUMEN
Recent research has shown that several species in the genus Monochamus, including Monochamus scutellatus scutellatus (Say) and Monochamus notatus (Drury), a close congener, are attracted to an aggregation pheromone, monochamol, but only M. s. scutellatus produces it. Investigations were conducted to determine if there is a diel rhythm in production of monochamol or response to monochamol + host attractants in field trials by M. s. scutellatus and M. notatus to prevent cross attraction with each other. Volatiles were collected from males and females of M. s. scutellatus and M. notatus every 8 h and analyzed by coupled gas chromatography-mass spectrometry. Traps baited with monochamol and the host volatiles α-pinene and ethanol were checked every 8 h in field tests. Only male M. s. scutellatus produced the pheromone, and did so in similar quantities during each 8-h time interval assessed, suggesting there is no diel rhythm in pheromone production. In field tests conducted in early to mid-July, significantly more M. s. scutellatus were captured during morning hours, and significantly more M. notatus were caught during afternoon or early evening hours, suggesting temporal partitioning of flight or in their response to the pheromone lures when both species are present. A temporal switch occurred later in the seasonal flight period (mid-August) when densities of M. s. scutellatus were low; all M. notatus and only one M. s. scutellatus were caught during morning hours. This suggests a temporal separation in mate location behavior when both species are abundant and using the same host to avoid interspecific mating.
Asunto(s)
Quimiotaxis , Escarabajos/efectos de los fármacos , Escarabajos/fisiología , Feromonas/metabolismo , Feromonas/farmacología , Animales , Monoterpenos Bicíclicos , Ritmo Circadiano , Etanol/farmacología , Femenino , Masculino , Monoterpenos/farmacología , New York , Distribución Aleatoria , Estaciones del Año , Conducta Sexual Animal , Especificidad de la EspecieRESUMEN
Monochamus scutellatus scutellatus (Say) and Monochamus notatus (Drury) are pests of pines due to their ability to vector pinewood nematode, the causal agent of pine wilt disease. Several species of the genus Monochamus use the male-produced aggregation pheromone monochamol, which could potentially be an important component of lures for monitoring these species. In this study, investigations were conducted to determine if traps baited with monochamol were more attractive to male and female M. s. scutellatus and M. notatus with addition of two host volatiles, α-pinene and ethanol. In field tests, traps baited with monochamol + α-pinene or monochamol + α-pinene + ethanol caught significantly more M. s. scutellatus and M. notatus than either controls or monochamol alone. The mean female to male sex ratios of captured beetles increased with the addition of monochamol to α-pinene or α-pinene + ethanol for M. s. scutellatus , but only increased for M. notatus when added to α-pinene + ethanol. These results indicate monochamol can be utilized in formulating highly attractive lures with host volatiles for detection and monitoring of these species.
RESUMEN
We report identification and field testing of 2-(undecyloxy)-ethanol (monochamol) as a sex-specific, aggregation pheromone component produced by males of Monochamus scutellatus scutellatus (Say) (Coleoptera: Cerambycidae), a longhorned beetle native to North America. A congener, Monochamus notatus (Drury), which uses the same hosts as M. s. scutellatus, also was attracted to this compound in field trials, suggesting it may be a pheromone component for this species as well. Panel traps were deployed along transects at each of five field sites in May 2010 to test attraction of native beetle species to a suite of cerambycid pheromone components, including monochamol, 3-hydroxyhexan-2-one, (2R*,3R*)- and (2R*, 3S*)-2,3-hexanediol, racemic (E/Z)-fuscumol, and (E/Z)-fuscumol acetate. In total, 209 adult M. s. scutellatus (136 females, 73 males) and 20 M. notatus (16 females, four males) were captured, of which 86 and 70%, respectively, were captured in traps baited with monochamol (means significantly different). Analysis of headspace volatiles from adult M. s. scutellatus by coupled gas chromatography-mass spectrometry and gas chromatography-electroantennogram detection confirmed that monochamol was produced only by males. Monochamol was not found in headspace extracts from adult M. notatus. This study provides further evidence that monochamol is a pheromone component common to several species in the genus Monochamus. The pheromone component should prove useful for monitoring native species for management purposes or conservation efforts, and for quarantine monitoring for exotic species.