Global impact of the moth

Helicoverpa armigera is a major pest of agriculture and horticulture in Australia, Asia, Africa and Southern Europe. This moth attacks more than 100 different commercial crops including cotton, maize, wheat, sorghum, sunflower, chickpeas, lucerne, lupins, soybeans, tobacco, tomato , lettuce, sweet corn, capsicum and beans and flowers including chrysanthemums, gladioli and roses. A closely related pest, Helicoverpa zea, is a major pest of many agricultural crop plants in North and South America.

The proposition that Helicoverpa armigera and Helicoverpa zea are different species is called into serious question by published data that shows high DNA sequence similarity. Crosses between these species have produced fertile offspring. Therefore there can be no doubt that a genome sequence for H. armigera would underpin research that could curb both armigera and zea, reducing the $5 billion annual bill for control costs and production losses.

Impact in the developing world

H. armigera has a devastating impact in the developing world. 50% of all insecticides used in India and China are used to control this pest. Farmers spend up to 40% of their annual income to buy chemicals to curb H. armigera. However, the moth is resistant to all classes of chemical insecticides leading to control failures. Facing total financial losses some farmers have committed suicide by drinking insecticides.

The evolution of resistance has lead to an increase in the amount of insecticides used. Crops may be sprayed by hand up to 20 times in a growing season. Farmers are regularly exposed to toxic chemicals in the process. The health impact of this exposure has not been precisely quantified. It has been suggested that one by-product of the liberal use of insecticides is that mosquitoes that carry malaria have become resistant and more difficult to control.

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