|Reagan, Thomas -|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: May 10, 2012
Publication Date: September 7, 2012
Citation: Showler, A.T., Reagan, T.E. 2012. Ecology and tactics of control for three sugarcane stalkboring species in the Western Hemisphere and Africa. In: Goncalves, J.F., Correia, K.D., editors. Sugarcane: Production, Cultivation and Uses. Nova Science Publishers. p. 1-39. Interpretive Summary: Of many stalk-boring lepidopterous pests that attack sugarcane, this chapter focuses on three species, the sugarcane borer, Diatraea saccharalis (F.); the Mexican rice borer, Eoreuma loftini (Dyar); and the eldana borer, Eldana saccharina Walker, because among them are examples of interspecific competition, similarities between species of different continents and differences between co-existing species, behavioral impacts on efficacy of different control tactics, variation in relationships with host plant species, and disparity in responses to environmental effects on the nutritional value of sugarcane plants. Each species is considered economically important, reaching the status of “key pest” in parts of their distributions. While chemical and biological control tactics have been successful against the sugarcane borer in areas of its New World distribution owing to relatively exposed life stages, the Mexican rice borer has been difficult to suppress with those tactics because of its cryptic habits (i.e., ovipositioning in tight leaf folds and curls and blocking tunnels with frass); hence, after invading south Texas, it supplanted the sugarcane borer as the key pest of sugarcane. The eldana borer of Africa is also cryptic and difficult to control, but it differs from the Mexican rice borer in some important ways, including its relationships with indigenous noncrop and cultivated host plants. Recent research has demonstrated that, despite discontinuation of insecticides against Mexican rice borers in south Texas, a new monitoring method combined with an insect growth regulator can hold populations below the economic threshold with only one application per season. Development of sugarcane resistance to each of the pests is underway, identifying desirable physical and biochemical traits, including the possibility of transgenic Bt defenses. Cultural practices for sugarcane borer control largely involve conservation of predators. Mexican rice borers and eldana borers both respond to stress- or fertilizer-enhanced nutritional quality of sugarcane plants; hence, irrigation and modest nitrogen application are recommended, as well as trap cropping and early planting. Control of all three stalkboring pests using integrated multiple tactics, particularly in combination with resistant sugarcane cultivars, is discussed.
Technical Abstract: This chapter focuses on three species, the sugarcane borer, the Mexican rice borer, and the eldana borer, because they are economically important in their ranges and because among them are examples of interspecific competition, similarities between species of different continents and differences between co-existing species, behavioral impacts on efficacy of different control tactics, variation in relationships with host plant species, and disparity in responses to environmental effects on the nutritional value of sugarcane plants. The biology and ecology of each of the species, and chemical, cultural, host plant resistance, and biological control tactics are described, and where possible, integrated pest management strategies are indicated.