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

Abstract

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.

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

“…Mizutani et al (2007) showed that there was individual variation in R. pedestris males in their attractiveness to the same species, and in the amount of pheromone produced. Endo et al (2007) revealed that adult age and reproductive diapause affect the production of pheromone components in P. hybneri males.…”

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

“…Males attracting conspecific adults and nymphs contained 14:iBu (Mizutani et al, 2007). In the present study, males used as attractants were determined to contain 14:iBu by GC-MS analysis; however, most of the males attracted to bait males during non-diapause and all males attracted to bait males during diapause did not contain 14:iBu, which is an essential component of the R. pedestris pheromone.…”

“…In males used as attractants in field experiments, males having well-developed fat-bodies showed a tendency to have more 14:iBu than those with undeveloped fat-bodies (Mizutani et al, 2007). These results indicate that the production of pheromone components including 14:iBu and the nutritional condition of males are closely related in R. pedestris.…”

“…The cage was fixed in front of a plastic plate (18ϫ25.5 cm) at a height of ca. 1 m from the ground (see Mizutani et al, 2007). Ten or twelve traps were placed at approximately 10 m intervals in a grassy field containing rows of coniferous trees at the National Agricultural Research Center (NARC) in Tsukuba, Japan.…”

“…Females of R. pedestris used as attractants do not have any pheromone components except for E2-6:Hx, and they are not attractive to conspecific individuals by themselves (Mizutani et al, 2007). However, it has not been clarified whether attracted adults have the four pheromone components except for E2-6:Hx.…”