Reported by Arif Maulana
[unpad.ac.id, 9/11/2020] Fruit fly is a major pest to horticulture commodity. Its attack can cause significant damage. Many horticulture products need better quality or fail to export because of fruit flies.
As stated by a Professor of the Department of Plant Pests and Diseases in the Faculty of Agriculture Universitas Padjadjaran, Dr. Agus Susanto, S.P., M.Si., the attack of fruit fly led the fruit to be rotten because it contained larva or maggots. Larva hatches from an egg, which is injected through the ovipositor of the female fruit fly.
“It is the cause in which many fruits appear smooth on the outside, but when split open, there are maggots inside,” said Agus.
This fruit’s condition led to an export rejection of many Indonesian horticulture products. One country that rejected “Gedong Gincu” mangoes with that condition was Japan. It resulted in a loss of up to 100% because of fruit fly attacks on fruits.
According to a field observation by Agus, there was no effective and efficient pest control yet, particularly to reduce female flies laying eggs inside the fruit.
“If it is not under control, fruit flies will cause damage in both quantity and quality. In terms of quality, many fruits will fall and rot. However, in terms of quantity, fruits cannot be sold or eaten because they contain maggots,” explained Agus.
Based on the field observation, Agus developed an attractant or fly lure made from natural materials. The attractant was required to attract male fruit flies with a particular compound. It would decrease the population of male flies and disturb the mating behaviour of the fruit flies.
“Later, if the population is decreasing, female fruit flies will not do the mating and egg-laying process,” he mentioned.
The main attractant compound developed by Agus was the methyl eugenol (ME) compound. This compound was used to attract male fruit flies. They needed the compound as pheromones, or attraction substances, which could make male fruit flies more superior or chosen by female fruit flies as mating partners.
By the ME compound, male fruit flies would be attracted and automatically hovered around the product or trap set with attractant.
It was quite easy to use the product. It could be applied to cotton and then hung on the trap. To kill fruit flies, the trap could be filled with water. After the fruit flies swarmed the cotton, they were immediately trapped in the water. For the straightforward method, Agus also developed Block ME, which already contained the ME compound, so it could be used conveniently and practically. The user did not have to apply the product to cotton.
They only had to hang the block, and male fruit flies would crowd around at any minute.
Based on the research result, the attractant by Agus was more effective than another product. It trapped more flies of the Bactrocera dorsalis complex species. This was also proven by the results of the trial conducted by BP3Iptek of West Java. The attractant developed by Agus Susanto could lower the damage level on fruits to 80 percent. The Block ME Attractant trial was carried out outside.
Natural Materials
The methyl eugenol on the attractant is from natural materials. The compound is usually gained from basil directly. However, Agus did not take it from basil because it had to be cultivated first and needed higher production costs.
Alternatively, the compound is obtained from clove leaf waste. The fall clove leaves are gathered and then go through the distillation process to produce an eugenol compound. Then, it is demethylated until methyl eugenol is generated. The degree of purity can be above 90 percent.
“So, the raw material can be gained easily at a cheap price. We have already cooperated with several farmers. Many farmers sell eugenol oil from clove leaf distillation,” added AGus.
Attractant was not only purely made from natural ingredients but also very safe. The product would not kill nontarget beings. Attractant was developed under the research grant, RAPID Dikti Grant 2015-2017, and Pusnas Dikti Grant for 2018-2020. As the beginning step, the product sample had been liked by many farmers in West Java and Sumatra.
It also cooperated with industry parties and was ready to be commercialized after permission from the Pesticide Commission was issued.
The product was expected to be beneficial in protecting horticulture products from fruit fly attacks. “I hope it can be accepted by farmers at a reasonable price, safer, more efficient, and easier to use,” mentioned Agus. (arm/SA)*
