Leveraging the ecology of invertebrate pathogens in microbial control

Authors: DARA, SURENDRA - University Of California - Cooperative Extension Service; GOBLE, TARRYN - Cornell University; Shapiro Ilan, David

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 9/30/2017
Publication Date: 1/1/2018
Citation: Dara, S. K., Goble, T. A., and Shapiro-Ilan, D. I. 2018. Leveraging the ecology of invertebrate pathogens in microbial control. In: Hajek, A. E. & Shapiro-Ilan, D.I., editors. Ecology of Invertebrate Diseases. Hoboken, NJ: John Wiley & Sons. p. 469-494.
DOI: https://doi.org/10.1002/9781119256106.ch13

Interpretive Summary: The overuse or misuse of broad spectrum chemical insecticides is harmful to humans and the environment. In contrast, application of biological control agents (natural insect predators, parasites and pathogens) offers an environmentally sound approach to insect pest suppression. Microbial control is a special branch of biological control that focuses on the use of insect diseases (microbes) to kill the target insect pests. The objective of this chapter is to review the factors that affect microbial control success and suggest approaches for improvement. Generally, the microbial agents that infect and cause disease in insects are not harmful to humans or the environment. Disease causing agents such as virus, fungi, bacteria and nematodes can be applied for short or long-term insect pest control. Success in microbial depends on various factors. The pathogen (disease causing agent) is ideally highly virulent (potent), persistent in the environment, and easy to mass produce, formulate and apply in the field. Consequently, to improve microbial control, approaches include improving the pathogen (its virulence or environmental tolerance) or enhancing methods of production and application. Improving microbial control and incorporating microbial control tactics into a pest management program leads to reduced impact on the environment and enhances food safety.

Technical Abstract: Microbial control is the management of pests with beneficial microorganisms, which may include bacteria, fungi, nematodes, protists, and viruses. This chapter reviews the approaches to microbial control, factors that affect efficacy, and methods of improvement. There are four basic approaches that include the release of microbial control agents through classical, inoculative, or inundative approaches to introduce organisms in either concentrated or large areas, and environmental manipulation which helps to conserve the released or existing organisms. Inoculative and inundative approaches are considered for augmentation of microbial control agents that may already exist, but at low levels. A diverse array of microbial control agents have been commercialized, each is effective against certain pests depending on their feeding habits and habitat. Abiotic factors (such as UV, moisture, temperature) and biotic factors (such as antagonists and synergists) impact the success of microbial control. Microbial control success can be achieved by aiming toward induction of epizootics within the agroecosystem. Microbial control programs can be improved via strain enhancement, or development of superior production, formulation, and application methods. Incorporation of microbial control into integrated pest management systems promises to enhance sustainability.