Survival and reproduction of lesser grain borer, Rhyzopertha dominica (F.)(Coleoptera: Bostrichidae) on flora associated with native habitats in Kansas

Authors: JIA, FENGYOU - KANSAS STATE UNIV; TOEWS, MICHAEL - UNIVERSITY OF GEORGIA; Campbell, James - Jim; RAMASWAMY, SONNY - PURDUE UNIVERSITY

Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/5/2008
Publication Date: 9/30/2008
Citation: Jia, F., Toews, M.D., Campbell, J.F., Ramaswamy, S.B. 2008. Survival and reproduction of lesser grain borer, Rhyzopertha dominica (F.)(Coleoptera: Bostrichidae) on flora associated with native habitats in Kansas. Journal of Stored Products Research. 44(4): 366-372. Doi: http://dx.doi.org/10.1016/j.jspr.2008.06.001.

Interpretive Summary: This paper reports results of experiments to determine the survival of a major stored grain pest, the lesser grain borer, on alternative foods found in prairie landscapes. This pest insect has a relatively broad host range and is often trapped at locations far from grain storage and at times of year when stored grain is not as readily available, which suggests that they may be exploiting other food resources to persist. We examined the ability of lesser grain borer to feed and survive on wood and seeds of trees, and seeds of grasses, forbs, and shrubs, that are commonly found growing on Kansan prairie landscapes. We found adult survival was generally poor on the tested whole grass and forb seeds, and that, although beetles readily tunneled, survival was generally poor on twigs from a wide range of tree species. In contrast, survival and reproduction on damaged acorns of several species of oak was high, although they were unable to feed on whole acorns. From a field site where lesser grain borer had been captured, we found that the majority of the acorns on the ground were damaged, and some adult lesser grain borer were recovered from acorns collected off the ground. The use of alternative food sources may be important in enabling populations to persist in landscapes and thus contribute to the colonization of new harvested wheat.

Technical Abstract: Capture of Rhyzopertha dominica in pheromone-baited traps located many kilometers away from grain storage suggests that this species may be reproducing in these areas. To investigate the potential for survival of this species on alternative hosts in the absence of grain, we conducted no-choice feeding assays with twigs and seeds of trees, and seeds of grasses, forbs, and shrubs, commonly encountered on Kansas prairie landscapes where R. dominica has been captured. In addition, R. dominica development and progeny production were assessed on seeds that adults were able to survive on for at least two weeks. Adult survival was poor on grass and forb seeds, although 13.4% of individuals survived on Canada wildrye, Elymus canadensis, seeds after two weeks, compared with 80.3% on wheat, Triticum aestivum, and 0.0% survival in the absence of food. Beetles readily tunneled into twigs from a wide range of tree species, but survival was generally low. A few individuals survived up to 4 weeks on honey locust, Gleditsia triacanthos. In contrast, bioassays showed that R. dominica could survive and reproduce on damaged seeds (acorns) of six species of oak, but not on undamaged seeds. For example, survival was 95.8% on damaged chinquapin oak, Quercus muehlenbergii. A survey of acorns at the original field collection site showed that the majority of the acorns on the ground had been cracked or bored by insects and small mammals. Furthermore, we recovered three R. dominica adults from acorns collected in the field and held in sealed containers in the laboratory. These findings suggest that R. dominica populations in Kansas can persist on wild acorns when grain is not available.