Turns out the kudzu bug, a recently discovered East Asian agronomic pest, and two invasive Asian thrips may have the potential to control another invasive pest from the Far East. All three insects appear to have a dietary preference for the invasive plant, kudzu.
“Kudzu’s ability to take over landscapes in the southeast has been enhanced by the absence of herbivores which limit its growth,” said Dr. Joe Funderburk, Pest Management Specialist at the University of Florida/IFAS North Florida Research and Education Center (NFREC) in Quincy, Florida. “In its native Asia, kudzu is host to numerous species of insects which help make it a good member of the plant community,” he said.
Funderburk is in the process of summarizing a replicated field experiment at the UF/IFAS NFREC in which several bean species, with different cultivars from each species, were evaluated. Legumes, like beans, soybeans, and kudzu, are especially attractive to the two invasive Asian thrips (Salpingothrips aimotofus and Megalurothrips distalis) and kudzu bugs.
The purpose of the field experiment was to determine the preferred plant hosts of the Asian thrips, Megalurothrips, and to evaluate the potential for damage from this pest. In 2012 it was determined both sexes of Megalurothrips distalis and their larvae congregate on kudzu flowers.
To measure the population, bean flowers from each cultivar were put in alcohol weekly for over a month and the thrips counted. The study’s conclusions are expected in the near future, but it is known this species is a serious pest to Asian bean production.
Additionally, kudzu bugs, likely from a nearby heavy kudzu infestation, moved into the beans. Observations of the beans indicated the kudzu bug numbers were very low with little potential for damage, including the soybeans which were part of this trial.
In a separate study, various legumes were sampled to determine the population and host preferences of the Asian thrips Salpingothrips aimotofus. This species, first detected on kudzu in Georgia, produces multiple generations each year in northern Florida, feeding and reproducing in very large numbers on the shoots of kudzu.
Soybeans are a host for these thrips but, to-date, populations remain small and non-damaging. Only thrips specialists are aware of their presence.
“Asian thrips and kudzu bugs are considered pests on legumes, such as soybean, and can cause quarantines, but they are beneficial when feeding on kudzu,” said Funderburk. “There may yet be control in the southeast for this century old plant pest,” he said.