Sampling method
Pillbugs are crustaceans and have become serious early-season problems in no-till fields, especially in south central KS. They must have a moist environment, which no-till often creates, and thus has allowed pillbug populations to greatly increase in some areas. Pillbugs usually feed on dead and decaying organic matter, but seem to relish feeding on young succulent soybean seedlings. Pillbugs are relatively easy to control except in no-till situations since they are under the residue and thus protected from any contact insecticide which may be applied as a foliar rescue treatment. They also have to bite the plant to get the toxin from a seed treatment, and this often kills the plant even though it also kills the pillbug. Early or late planting seems to be the best (only) option for notillers in pillbug infested areas. For more information see MF2855, Pillbugs: ksre.ksu. edu/bookstore/pubs/MF2855.pdf .
Non-chemical controls
Foliar application of labeled insecticides also has not proven effective. Pillbugs, like many crustaceans, are susceptible to insecticides. But crop residue under which these pests exist often intercepts the spray, protecting the pillbugs and allowing them to continue feeding on seedling plants. No-till soybeans are the crop most often affected because of the timing of the planting, the presence of damp residue, and the susceptibility of young plants to feeding injury. Pillbug problems have not been apparent in conventional tilled fields because there is less soil moisture and cover available and pillbugs need a moist environment. Avoiding pillbug feeding damage, especially to no-till soybeans, has proven difficult. One management practice that has proven successful is to plant a few weeks earlier or later than usual. But this may not be acceptable from an agronomic standpoint and can be greatly affected by weather. Another practice that has worked is to till fields every other year. Tillage reduces pillbug populations. Alternating between till and no-till reduces the amount of time for pillbug populations to reach damaging levels. Beneficials, i.e. predators, parasites, and pathogens, have not been a factor in any of the pillbug populations examined to date and few have been noted in the literature. Thus, biological control will probably not provide much relief in the near future.
Content authors
Disclaimers
This content may not be suitable for states other than Kansas.
