Hormonal Control of Adult Diapause in the Brown-Winged Green Bug, Plautia stali SCOTT (Heteroptera : Pentatomidae)

To improve the procedures for estimating the abundance of the rice bug, Leptocorisa chinensis Dallas (Heteroptera: Alydidae), field monitoring using traps baited with synthetic attractant was conducted in Tsukuba, central Japan from 2002 to 2006. A mixture of (E)-2-octenyl acetate and 1-octanol, in a ratio of 5 : 1 and incorporated into a plastic pellet, was used as bait on sticky boards and placed at study sites from early June to the end of October. The attractantbaited traps were able to detect the starting of the migration period of the overwintered generation and the population increase of the first generation. The number of trapped insects decreased rapidly after early September, while the number of insects in second generation increased in the grassy weeds field. The decreased temperatures and shorter daylength of autumn (which will have induced reproductive diapause) may have affected the attractiveness of the baited traps. The ratio of males to all captured L. chinensis was 0.88-0.96. Most captured adults had no food in their stomachs, and most males were sexually mature. These results indicate that the males trapped had actively moved for two possible reasons: to search for food and/or to search for females. Based on comparisons between the results of baited trap monitoring and sweep-net surveys, it was considered that immigrant period and density of L. chinenis in the poaceous plants fields depend on the density of dispersal individuals and the heading period of the plants.

Section: Methodsmentioning

confidence: 99%

Seasonal attraction of the rice bug, Leptocorisa chinensis Dallas (Heteroptera: Alydidae), to synthetic attractant

Watanabe

Takeuchi

Ishizaki

et al. 2009

“…In some heteropteran species, diapause and nondiapause males can be discriminated by the degree of development of the ectodermal accessory gland (Kotaki and Yagi, 1989;Numata and Kobayashi, 1989). Male accessory glands are involved in reproduction in many insect species (Chen, 1984;Gillott, 2003) and the secretion produced by male accessory glands is transferred to the female during copulation.…”

Section: Introductionmentioning

confidence: 99%

Possible function of Piezodorus hybneri (Heteroptera: Pentatomidae) male pheromone: Effects of adult age and diapause on sexual maturity and pheromone production

Endo

Yasuda

Matsukur

et al. 2007

To estimate the biological function of the male-produced pheromone of Piezodorus hybneri, we investigated the relationship between sexual maturity and pheromone production. Copulation was first observed at day 4 after emergence of males. The males showed high mating activity between days 5 and 15. Development of the ectodermal accessory gland (EAG) was also investigated as an indicator of male sexual maturity. The EAG, which was entirely immature at adult emergence, developed gradually between days 3 and 10. Males started to produce pheromones at days 3 to 5 after adult emergence, and production became maximal at days 5 to 10, remaining at a high level until day 30. No pheromone components were detected in any diapause males, which showed neither mating behavior nor EAG development. These results indicate that P. hybneri males produce their pheromone simultaneously with the development of sexual maturity, and thus the function of this pheromone seems to be related to sexual behavior.

“…In some bug species, including R. pedestris (Numata and Kobayashi, 1989), P. crossota stali (ϭP. stali) (Kotaki and Yagi, 1989) and Leptocorisa chinensis (Heteroptera: Alydidae) (Tachibana and Watanabe, 2007), the size of the EFR can be used as an index for the diapause status of the male. The present study clarified that diapausing males of R. pedestris with immature EFRs did not have pheromone components at all, while non-diapausing males with mature EFRs had pheromone components.…”

Section: Discussionmentioning

confidence: 99%

Influence of photoperiod on attractiveness and pheromone contents of the bean bug, Riptortus pedestris (Heteroptera: Alydidae)

Mizutani

Wada

Yasuda

et al. 2008

The attractiveness of Riptortus pedestris males reared in short (10L14D) and long (16L8D) photoperiods to field adults was examined in field trap experiments in autumn. Simultaneously, the pheromone component occurrences and the condition of the internal organs of bait males were clarified by GC-MS analysis and dissection, respectively. In two field experiments, male baits reared in the short photoperiod did not attract any conspecific adults, while males reared in the long photoperiod did. Tetradecyl isobutyrate (14:iBu), which is an essential component of the R. pedestris pheromone, was not detected in any of the extracts of male baits reared in the short photoperiod, while the component was often detected in the extracts of male baits reared in the long photoperiod. In the extracts of 0-to 12-day-old males reared in the short photoperiod in a laboratory, 14:iBu was not detected at all. Males reared in the short photoperiod in the field and laboratory experiments had an immature erection fluid reservoir, indicating that the males entered a reproductive diapause. The present results indicate that photoperiod greatly influences the sexual maturation and pheromone emission of males in R. pedestris.