Researchers develop ‘sex pheromone’ insecticide

Insect traps containing “sex pheromones” for 19 pests have been developed by the Taiwan Agricultural Chemicals and Toxic Substances Research Institute, part of the Council of Agriculture, after it experimented on the “fragrance” emitted by insects during reproduction.
   
These pheromone traps are applicable to crops spanning groves, sweet potatoes, vegetables, corns, sugarcanes, rice and stock medicine herbs, offering an alternative to chemical pesticides.

The institute said the sex pheromones cause no side effects, but effectively reduce the number of pests.

It encourages farmers to combine their use with other pesticides for the best results, both to establish a pest prevention system and reduce the damage that conventional pesticides have on the environment.
   
Citing the carambola fruit borer (Eucosma notanthes Meyrick) as an example, Hung Chiao-chen, a researcher at the institute, said that if the bug traps capture less than 10 of these borers a week, it means no pesticide is needed for starfruit groves.
   
A sweet potato garden employed four pheromone traps to lure and exterminate sweet potato weevils (Cylas formicarius) since the sowing period and posted a success rate of between 55 and 60 percent.
   
Cauliflower fields tested have each saved up to NT$5,000 with the help of 20 pheromone traps set up to kill diamondback moths.

Hung said sex pheromones, which are emitted during reproduction, have the same alluring effect on insects as perfume on humans.
   
They are species-specific and effective in decreasing the density of any one pest, while being non-lethal to other organisms, she said.
   
Each trap contains 0.1mg to 5mg of sex pheromones, which can last anywhere between one and six months. These pheromones evaporate easily, enticing pests through scents and leaving no residue, she said, adding that they are also a useful indicator of pest population sizes.
   
The 19 sex pheromone traps developed by the institute include ones targeting fruit-eating pests, such as the litchi fruit borer (Conopomorpha sinensis), the carambola fruit borer, the macadamia nut borer (Cryptophlebia ombrodelta), the peach moth (Grapholita molista), the guava mealybug (Planococcus minor), the citrus mealybug (Planococcus citri), the casuarina moth (Lymantria xylina) and the cocoa Tussock Moth (Orgyia Postica).
   
Others aimed at grain-and-special-crops-eating pests, including the Asian corn borer (Ostrinia furnacalis), the sweet potato weevil, the Asiatic rice borer (Chilo suppressalis), the tea tortrix (Homona coffearia), the almond moth (Cadra cautella) and the Indian meal moth (Plodia interpunctella).
   
Four dry pheromone traps have also been made available to farmers by the institute. They are made to counter sweet potato weevils, carambola fruit borers, casuarina moths and lepidopterans in general, the institute said.