Caterpillars that attack trees in several regions in Indonesia are considered as a normal cycle. However, the high population of caterpillars is currently a concern for many people. According to Deputy Minister of Agriculture, Dr. Ir. Bayu Krisnamurthi, the high population of caterpillars occured due to climate change in 2010. This change caused the caterpillar’s food abundant while the natural enemies are pressured and decreased. "So, there is the caterpillar booming," said Bayu at the UGM Faculty of Agriculture on Thursday (14/4), responding to the phenomenon of caterpillar attacks in Indonesia.
Archetornis sp. caterpillar species that attacks Probolinggo and some other areas, in Bayu’s observation are considered as the type of caterpillar that causes most harm. As for other types of caterpillars are considered harmless. "However, we can understand the concerns of society. After all this caterpillar, in the Javanese term, is always nggilani(disgusting)," he said.
Bayu admitted that the observations conducted by UGM, Ministry of Agriculture and several other colleges have not been completed up until now. In Probolinggo, which is considered as the most affected area, actually the attack area was not as bad as we imagined. "It’s relatively small, only 1.5% of the total mango trees. It means that from 1.8 million trees, the affected is only approximately 14,500 trees," he explained.
Of the 14 ,500 trees, 40% -50% or approximately 7,000 mango trees are predicted not to bear fruit for this year. Even so, many people still have difficulty to predict the amount of losses suffered by the community. "However, once again I emphasize that the plants did not die. Hopefully, next year these mango trees will recover and produce fruit again," he added.
In general, this caterpillars attack is starting from 2 branches, 3 branches, 5 branches, and so on. Luckily, in Probolinggo district the natural parasites are starting to grow as natural enemies in form of mold and bacteria from the worm itself. "In this Probolinggo area the parasitation rates (the amount of caterpillars attacked by its natural parasites) has been 80% so that by simple calculations in the next few weeks these caterpillars are expected to disappear naturally because it is part of ecological processes. That way, if they are not dead, the living ones would become moths," he explained.
Related to the issue, UGM experts are currently helping the process of forming these natural parasites. By managing the parasites, the prevention is expected to be completed quickly. After all, biological prevention is the most appropriate step of a series of choices. "That way the prevention using the insecticide becomes the last choice even though the government, in this case the Ministry of Agriculture, has prepared insecticides to eradicate the attack," said Bayu.
Furthermore, Bayu explains that these caterpillars have actually been found since 1879 or more than 100 years ago. Meanwhile, the population boom occurs seasonally. Caterpillars that attacks in Yogyakarta are different from that those in Probolinggo. "Of course, we will continue to study it; this caterpillar certainly is a nocturnal. While in the daytime, it is shy in the sun hence it likes to hide in trees, and in the daytime that's when the right time to exercise control," said Bayu.