Nov. 6, 2013
The sustained view that agricultural crops could be made to produce more by increasing usage of synthetic chemicals is now outdated. Of the 2.4 billion kilograms of pesticides used in 2007, the United States accounted for about 20 percent of the total. It was noticeable that American farmers are relatively sparing in their use of pesticides — using just 2.2 kilograms per hectare of arable land. Comparatively, in China farmers used close to 10.3 kilograms per hectare. The reason could be due to lesser training in farm sectors and also unavailability and popularity of alternatives technologies. The scenario in China may be not much different from other developing countries of the world.
Disintegration of idea in developed countries has allowed the concept of IPM (Integrated Pest Management) to play a vital role in modern agriculture. Integrated pest management is more of intelligent pest management with meeting of ideas and implementation. Until recent times, the chemical control of insect pests relied almost exclusively on the use of artificial, laboratory based chemicals. Modern management of insect pests has however partly shifted to the use of naturally occurring chemicals, some produced by insects themselves.
Today scientific identification is far simpler and enormous data have accumulated on insect and their pheromones. Pheromones are often classified according to their effect on the target animal. For instance, the causing of alarm is a function of the alarm pheromone; trail pheromone if the function is to set up a trail and if it is for aggregate it is aggregation pheromone. But it is the sex pheromones which has come useful for exploitation in agriculture.
Usage of sex pheromones and pheromone based technology had made possible the shift from spraying heavily to a softer approach in which the insect pests are lured by the vapors and volatile from the pheromone formulations to designated sites. The insects are either caught up in custom designed traps, or are lured to a site “killing site” where chemical control can take over. The popularity also comes from the fact that they are compatible with other control techniques such as the use of resistant cultivars, microbial other biological agents, and conventional insecticides.
Pheromone lures have been developed for many pest species around the world and used extensively for population monitoring and mass trapping. Pheromone baited traps reduce the abundance of one or both sexes of the species targeted. Traps are placed at regular distances from each other; the density of traps employed however will greatly depend on factors that vary with each species and each situation. Pheromone usage has developed in three main ways such as for pest monitoring, mating disruption and mass-trapping.
Pheromones in Philippines Market
Recent understanding on the adverse effects of large scale usage of pesticides has brought in a number of new approaches in managing pests in crops such as mango, sweet corn, rice, coconut and oil palm in Philippines. Trials conducted have shown excellent efficacy of the test products. Pheromones were used to provide a picture of pest population at a particular time and space, and also used to guide pest control. All the initial information collected was extrapolated, and the population information obtained was used for assessment of the infestation and redirecting necessary control measures. However the most popular application of pheromones remained to be in population monitoring. Disruption of mating by saturating the environment with pheromone vapors is possibly the next test to be undertaken.
Recently a new generation of formulation called SPLAT® (Specialized Pheromone & Lure Application Technology) which consists of a biologically inert matrix for the release of semiochemicals with or without pesticides was tested. The product is developed and manufactured by ISCA Technologies USA. Due to its amorphous and flowable quality, SPLAT offers the most flexible method of applying pheromone with attract & kill formulations. The long lasting formulation mixed is laced with an insecticide which when touched killed the insect pest. This design is suitable for crops which are hard to spray and monitor frequently such as fruit trees. In addition the formulation easily accommodates a variety of application methods such as manual, mechanical and automated.
SPLAT was tested in a number of crops such as mango against fruit flies (Bactocerous dorsalis) and oil palm against Rhinocerous beetle (Oryctus rhinocerous) in the Philippines. The product a lure-and–kill formulation was applied in a 2 gm dollop using a conventional caulking gun on areas of trees to attract the pest and kill them when they come in contact. The product proved to be efficacious in all the field trials conducted, and long term trials are being planned for evaluating the economics of product in relation to productivity.
The opportunities and potential for pest management using pheromones are abundant in SE Asia. With growing investment of overseas business houses in agriculture in this region solely for tapping the export market, pheromones could be crucial. Pheromones could reduce insecticide usage, residue counts and can assist phytosanitary clearances. However the difficulty of using pheromones comes from unclear registration procedures currently in effect in all SE Asian countries including Philippines. In the recently concluded International Chemical Ecology Conference (ICEC 2013) in Melbourne, issues on registration where discussed by experts from various developed and developing countries. It was evident that only a few products are registered for actual use around the world, in spite of proof that the pheromones are safe. The need for easing out the registration could be expedited by categorizing actual usage by crop and non-crops and other determinant factors. This could see the use of the product sooner in countries like Philippines.