2nd Place: Enhancement of feeding and dispersal ability in the bean bug, Riptortus pedestris (Hemiptera: Alydidae) mediated by environmentally-transmitted gut symbionts
Monday, November 14, 2022
11:18 AM – 11:30 AM PT
Location: Vancouver Convention Centre, Meeting Room 304/305
Gachon University Goyang, Kyonggi-do, Republic of Korea
The bean bug, Riptortus pedestris, is a polyphagous insect pest which forms mutualistic symbiosis with Caballeronia insecticola. It has been revealed that C. insecticola provides enhancement in the fitness of R. pedestris such as development and fecundity indicating the evolution of physiological links between the two organisms. However, potential effect of symbionts on the behavioral traits of the host is currently unknown. In this study, we evaluated the effect of symbiosis on behavioral traits of insects with regard to feeding and dispersal by comparing them between symbiotic and apo-symbiotic adults under laboratory conditions. Feeding behavior was evaluated over 10 days by measuring food consumption rates and body weights of adults. Also, the frequency of feeding attempt was evaluated. Dispersal behaviors including horizontal walking and flight were evaluated using EthoVision and tethered flight mill systems over 4 hours. Symbiotic insects consumed significantly less amount of soybean per body weight than apo-symbiotic ones (P < 0.05). However, there was no significant difference in daily weight gain by adults between the two groups, suggesting that symbiotic adults could maintain assimilation efficacy at levels comparable to that of apo-symbiotic ones while consuming less food per body weight. Indeed, symbiotic insects displayed significantly less feeding attempt (P < 0.05). Finally, symbiotic adults displayed greater horizontal walking ability (P < 0.05) and also flight distance (P < 0.05) compared to apo-symbiotic ones. Our results provide the effect of symbiosis on behavioral traits of host insects at individual level, which may contribute to increase in the population growth of symbiotic insects.