The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used

Are banana weevil borers a vector in spreading Fusarium oxysporum f. sp cubense tropical race 4 in banana plantations?

Fusarium wilt of banana is a destructive plant disease, caused by the soilborne pathogen Fusarium oxysporum f. sp. cubense (Foc). Once established, it spreads rapidly, destroys the banana plants and builds up inoculum in the soil. To improve control and containment strategies, this study examined the pattern and possible methods of Foc tropical race 4 (Foc TR4) spread on a plantation. To date, root-to-root dispersal within the soil has been the presumed means of spread, but the fact that the spread of Foc TR4 occurred beyond neighbouring plants on the four fields assessed inferred that this is not the only mechanism. The banana weevil, Cosmopolites sordidus, is widespread in banana plantations and viable spores were found on the exoskeletons of ten per cent of the weevils, which infers that they may be a vector. Controlling vectors such as C. sordidus in banana plantations may therefore help minimise the spread of Foc TR4