Research Needs and Potential Effects of Biomass Crops on Pest Management

Projected demand for one billion or more tons of plant biomass for ethanol and other uses may be partially met using crop residues, but >10 million ha of perennial grass and tree crops also may be needed. Limited research has been conducted on management of insects in biomass crops, but agricultural change on a scale of several million hectares indicates established or emerging pests will have impacts on management in both perennial and annual crops. For crops without significant food or feed uses (primary-use biomass crops), immediate research needs are general because little is known regarding their insect herbivores and insect-transmitted pathogens or their effects on biomass. Recent work in perennial grasses has revealed species that were undescribed previously, described but without known host associations or other general biological information, or well-known pests of food or feed crops. Conversely, in food or feed crops modified for biomass production (secondary use), information on pest biology and management should overlap with their close-relatives (e.g., corn for food or feed versus tropical maize for biomass), with some changes needed in economic thresholds or management strategies. To the degree that biomass crops and food crops share insects and insect-transmitted pathogens, insects provide an avenue for interactions between biomass and food crops. Some possible effects of biomass crops are positive, such as providing refugia from insecticides and acting as sources for natural enemies or pollinators. Unfortunately, broad conclusions about the effects of biomass crops are difficult to make because the outcomes depend on which biomass crops are planted, where they are planted, and how they are managed. Additional investment and interdisciplinary research are needed to address new pest management challenges posed by the expansion of biomass crops.