Effect of temperature on the maintenance of pentatomid gut-associated symbionts
Simone Prado, email@example.com, University of Hawaii - Manoa, Plant and Environmental Protection Sciences, 3050 Maile Way, Room 310, Honolulu, HI, Kim Hung, firstname.lastname@example.org, University of California at Berkeley, ESPM, 137 Mulford Hall, Berkeley, CA, and Rodrigo Almeida, email@example.com, University of California - Berkeley, Environmental Science, Policy and Management, 137 Mulford Hall, Berkeley, CA.
Acrosternum hilare (Say) and Murgantia histrionica (Hahn) (Hemiptera, Pentatomidae) have vertically transmitted Erwinia-like bacterial symbionts in the posterior region of their midgut. We determined the impact of temperature (25°C and 30°C) on the biology of both insects and their symbionts. A. hilare showed higher mortality in the 1st and 5th instars at 30°C (26% and 6%, respectively) when compared with 1st and 5th at 25°C (12% and 2%, respectively); its developmental time was not affected by the temperature. Egg masses, 5th instars and adults of A. hilare were symbiont-positive at 25°C, but those at 30°C were symbiont-negative from the 2nd instar on. M. histrionica had similar developmental time at both temperatures, but 2nd instar's mortality at 25°C (14%) was higher than at 30°C (8.7%). M. histrionica had 73.3% of 5th instars positive for their gut symbiont at 25°C, but all were negative at 30°C. Our results show that 30°C affected the maintenance of this symbiosis in both insects. M. histrionica increased mortality at 25°C suggests that this association may be pathogenic and have a fitness cost. In summary, our data show that increased temperature cleared two pentatomid species of gut-associated symbionts and differentially affected their fitness.
Species 1: Hemiptera Pentatomidae Acrosternumhilare (green stink bug) Species 2: Hemiptera Pentatomidae Murgantiahistrionica (harlequin bug)