Effect of Feeding on the Attractiveness of Riptortus clavatus (Thunberg) (Heteroptera: Alydidae) Males to Conspecific Individuals.

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: Effects Of Temperaturementioning

confidence: 99%

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

Watanabe

Takeuchi

Ishizaki

et al. 2009

“…In R. pedestris, feeding and attraction to conspecific individuals are closely related (Morishima et al, 2005), suggesting that the pheromone system of R. pedestris plays a key role in food exploitation (Yasuda et al, 2007b). A similar strategy was proposed in the pheromone system of the brownwinged green bug, Plautia crossota stali (P. stali) (Heteroptera: Pentatomidae) (Shiga and Moriya, 1989) and the predatory spined soldier bug, Podisus maculiventris (Heteroptera: Pentatomidae) (Aldrich et al, 1984;Sant'Ana et al, 1997;Shetty and Hough-Goldstein, 1998).…”

Section: Introductionmentioning

confidence: 83%

Pheromone contents and physiological conditions of adult bean bugs, Riptortus pedestris (Heteroptera: Alydidae), attracted to conspecific males during non-diapause and diapause periods in fields

Mizutani

Yasuda

Yamaguchi

et al. 2008

Self Cite

The contents of five pheromone components and the physiological conditions of wild male and female Riptortus pedestris attracted to bait males during non-diapause (from early July to early September) and diapause (from midSeptember to mid-October) periods in the field were examined. Although tetradecyl isobutyrate (14:iBu), an essential pheromone component, was detected in males attracting conspecific individuals, this component was not detected in almost all males attracted to bait males. This indicated that the attracted males are not attractive to conspecific individuals unlike bait males. During non-diapause, (E)-2-hexenyl (E)-2-hexenoate and (E)-2-hexenyl (Z)-3-hexenoate, which are synergistic components of the pheromone, were detected in most males. On the other hand, these components were not detected in most of the males during diapause, indicating that the function of these two components in the attractiveness of males might be related with the sexual communication mechanism. (E)-2-hexenyl hexanoate was detected in almost all males and females attracted to bait males. The physiological conditions were similar between adults attracted to bait males during non-diapause and diapause. Most of the attracted adults had little or no food in their stomachs. This suggested that male-attracted adults of R. pedestris are starved and are searching for suitable host plants.

“…In R. pedestris, males provided with food only released three pheromone components (14:iBu, E2-6:E2Hx and E2-6:Z3Hx) (Leal et al, 1995) and such males attracted adults and nymphs (Morishima et al, 2005). Morishima et al (2005) suggested that pheromone release in males was affected by their fat-body development. These results suggest that the production of 14:iBu is closely related to fat-body development.…”

Section: Discussionmentioning

confidence: 99%

Individual variation in the amounts of pheromone components in the male bean bug, Riptortus pedestris (Heteroptera: Alydidae) and its attractiveness to the same species

Mizutani

Yasuda

Yamaguchi

et al. 2007

Self Cite

The individual variation of R. pedestris males and females in their attractiveness to the same species and the amounts of five pheromone components were examined in field experiments and GC-MS analysis, respectively. The number of adults attracted by a single male varied greatly among the individuals tested. The number of adults attracted was 0.92Ϯ0.12 (meanϮSE/day). Of 64 males examined individually, four attracted three or more adults per day, while 12 males attracted only 0.5 adults or fewer per day and 14 individuals attracted no adults. The five pheromone components also differed greatly among those males. As for tetradecyl isobutyrate (14:iBu), which is thought to be an essential component of the pheromone, it was apparently detected from 46 males while eight had only a low amount of 14:iBu and ten had no 14:iBu. Some of the males had 14:iBu without having (E)-2-hexenyl (E)-2-hexenoate (E2-6:E2Hx) and (E)-2-hexenyl (Z)-3-hexenoate (E2-6:Z3Hx), which are synergistic components of the pheromone, and the rest had E2-6:E2Hx and/or E2-6:Z3Hx without having 14:iBu. The amount of 14:iBu or octadecyl isobutyrate (the fourth pheromone component) showed a positive and significant co-relationship with the number of attracted adults. Males with a well-developed fat-body tended to have more 14:iBu and to attract more adults than those with an undeveloped fat-body. Most of the females tested individually did not attract conspecific adults, and had only (E)-2-hexenyl hexanoate, the fifth component of the pheromone.