The caterpillar pest attacks that hit eight regions in Indonesia such as Probolinggo, Kendal, Payakumbuh, Yogyakarta, Banten, Batu, Bali and Subang are not entirely resulting in adverse economic impacts on agriculture. Based on research by UGM agricultural team, Probolinggo region is the only region that became the most severely affected area while in other areas the attacks are still under the normal threshold limit.
The information was raised in the Forum Discussion Group of caterpillar pest outbreak response, Thursday (5/5), in the UGM Central Office. The discussion organized by the UGM’s Research and Development of Agriculture Educational Garden (KP4) presents a variety of caterpillar pest experts, including Dr. Suputa, agricultural pest expert, Prof. Dr. Ir. Bambang Hendro Sunarminto, SU, Entomology expert, Hidayat Soesilohadi and cultural observer, Prof. Dr. Sumijati Atmosudiro.
Suputa said that from eight caterpillar pests affected regions that he observed, only Probolinggo that experienced the worst outbreak. It is recorded that caterpillars attacked 14 thousand mango crop of farmers. His observations in Probolinggo with UGM agriculture team has produced an evaluation of caterpillar populations and natural enemies through socialization of PENDAMA tube utilization as a means of natural enemy conservation and performed UV installation to catch the caterpillars’ moth.
The field observation continued after the schools socialization. Observations were conducted on mango plantation. The observations include the physical condition of mango plants, the number of caterpillar population per mango tree, and the parasitation level either by parasitoids or pathogens. "The temporary result shows that the population of caterpillars in Probolinggo is very low, only 2 to 5 caterpillar instars 1 and 2 per plant, and some mango plants even did not have any caterpillar at all. Meanwhile, the parasitation level of caterpillar’s pupa especially Arctornis sp. reached 85.15 percent.
He added the complex role of natural enemies (parasitoids and pathogens) in the field that was assisted with the wise application of pesticides conducted only once by the Department of Agriculture in East Java using deltamethrin active chemical in several places and Lamda sihalotrin in other places has proven able to reduce caterpillar population to the secure threshold.
"The complex of natural enemies that play a role in the decrease of caterpillar population in Probolinggo is an insect pathogen Paecilomyces sp., larva-pupa Parasitoid Compsilura concinnata, and Brachymeria lasus," he said.
According to Suputa, caterpillar outbreaks in Probolinggo have been resolved properly and no longer a serious problem. This condition is expected to support for the flowering phase and the formation of perfect mango fruit since the mango fruit is very dependent on climate, especially on the dry and rainy seasons because if the flower season has arrived and it was raining, flowers will fall out, not producing any fruit.
To anticipate the outbreak of caterpillars in the future, Prof. Sumijati stressed the importance to gives the community the understanding that some kind of worm-eating birds, such as birds of Sri Gunting, sikatan, finches, glatik and prenjak, are prohibited to be hunted. The ngangrang ants and other insects that consume caterpillars are also forbidden to be hunted and traded.
Meanwhile, Head of KP4 Dr. Agus Cahyono said the caterpillar population increase is due to climate change, which damaged the food chain due to absence of many predators because of hunting and trading.