The earwig insect, a revolutionary method of controlling pests

An insect that used to be thought of as harmful may very well pave the way for a revolutionary method of controlling insects in rice and vegetables at a very low cost and without endangering the health of farmers and consumers. Some people believe the earwig (Dermaptera spp.) transmits diseases and harms people as well as animals. The name originates from the superstition that earwigs crawl into the ears of sleeping persons and bore into the brain.

Dante Sabacan, an agriculture technologist in the Philippines has proven that earwigs, after all, have some beneficial uses. For one, they could drastically cut down the cost of production, as farmers no longer need to apply insecticides.

In onion production in the Philippines, farmers spend at least 70,000 peso ($1475) a hectare for insect control using chemical insecticides, which endanger their health and consumers as well. What’s worse is that the use of chemical insecticides does not provide full guarantee for insect control.

Sabacan has been growing earwigs in his house since 2004 after undergoing a refresher course on integrated pest management conducted by the Philippine Rice Research Institute. At first, his wife, Anali, wanted to throw his cultures away but she has learned to appreciate the insects as well as her husband’s dedication after learning of their benefits to farmers. Using his own money and on his initiative, Sabacan produces around 50,000 earwigs a week using corn cobs as the culture medium. Corn cobs entail no cost since these are simply thrown away by corn growers. This earwig population can protect around five hectares a week or 80 hectares a season. He believes that earwigs are ideal for insect control in vegetables.

To grow earwig successfully, he sterilizes the soil by "frying" it to prevent the accumulation of fungus. He also uses corn cobs as nests for the insects. He covers his culture containers with a net to protect the earwigs from lizards and flying insects. He sprays the surroundings with an ant repellent to prevent ants from eating the earwigs. He also gives water and crushed dog food to the insects twice a week. Most of all, he checks on the insects daily – in the morning, after work and before bed time. Compared to other insects that can be used for pest control such as spider, dragonfly or trichogramma, the earwig is the easiest to culture. It can produce 300 off spring in 14 days, which are enough for easy application in one square meter. Earwigs paralyze and feed on the bodies of their prey, usually armyworms, thus preventing them from damaging crops before they can feed on them.

Already, farmers in Sto. Domingo, Nueva Ecija are benefiting from Sabacan’s efforts. For instance, farmer Romulo Salamanca, who used to lose at least 25 percent of his expected yield despite using different insecticides, now loses only five percent, with insect-damage now confined to the tips of corn ears. He also uses earwigs in his 1.2-hectare rice farm. Without using insecticides, his yields have been increasing and he has been saved from spending more than P2,000 ($42) for insecticides alone.

Mario Domingo, who has been farming for more than 30 years, has become a firm believer of Sabacan’s "earwig technology." He started to use it in 2006 in his three-hectare farm planted with rice, tomatoes, water gourd and squash, saving at least P15,000 on chemical insecticides. He also used earwigs on his onion crop.

Domingo said the use of earwigs is well worth repeating. For this year’s onion crop, he did not use any chemical insecticide and saved around P70,000 per hectare by using earwigs and the PhilRice vesicular ambuscular mychorrizae (VAM). His wife, Neneng Domingo, said their neighbouring farmers were amazed at their onion plants, which grew fast and healthy without spending so much money. As a result, they are now eager to use earwigs in the next cropping season.

The Philippine Star