Monday, December 11, 2006

The mechanism for transmission and acquisition of symbiotic bacteria in the bean bug Riptortus clavatus (Heteroptera: Alydidae)

Yoshitomo Kikuchi, yoshitomo.kikuchi@uconn.edu1, Takahiro Hosokawa2, and Takema Fukatsu2. (1) University of Connecticut, Molecular and Cell Biology, 91 N Eagleville, Storrs, CT, (2) Advanced Industrial Science and Technology (AIST), Biological Resouces and Functions, 1-1-1 Higashi, Tsukuba, Ibaraki, Japan

Almost all phytophagous stinkbugs (Heteroptera) possess symbiotic bacteria in their midgut ceca. Here we report the mechanism for transmission and acquisition of the symbiont in the Japanese bean bug Riptortus clavatus (Alydidae). The results of diagnostic PCR and rearing experiments rejected the possibility of vertical transmission. In contrast, almost all nymphs reared on soil-grown soybean plants acquired the symbiont, and only nymphs placed in the sterile bottles inoculated with the cultured symbiont acquired the symbiont. Body size and dry weight of the infected adults was significantly larger than that of the uninfected ones. From these results, we conclude that the bean bug acquires the benevolent symbiont not through vertical transmission but from the surrounding environment.

Species 1: Hemiptera Alydidae Riptortus clavatus (broad-headed bug, bean bug)
Species 2: Hemiptera Alydidae Leptocorisa chinensis (broad-headed bug, rice bug)