Insect attack-A Warning Signal of Environmental Disruption.
There is a phenomenon which has been happening for some weeks in East Java when thousand of caterpillars (Desiciria inclusa) attack some villages in Probolinggo. Probolinggo is a city which is also known as the country's center of mango production. People in Probolinggo are mostly make a living from growing mango trees and sell the fruits to all parts of the country including for export.
Thousand of caterpillars belong to species Desiciria inclusa, have heavily widespread in 7 sub districts of Probolinggo city, gnawing all kinds of trees they manage to crawl. Since growing mangoes is the main source of income, the villagers at those villages suffer a lot for not being able to harvest their mangoes. Around 9000 mango trees have been reported got damage and fail to bloom, and not to mention other productive crops other than mangoes.
Local government of East Java Province make some efforts, tries to anticipate the attack to other plantations in the area like coffee and cacao.
What Has Caused Environmental Imbalance ?
There are some explanations given by entomologists and environmental experts about the causes of caterpillars attacks in East Java :
1. Extreme Weather :
Indonesia has two seasons: rainy and dry seasons. Those seasons determine animals life cycle in nature including the metamorphosis of insects. In 2010 until early 2011 rainy season has taken place much longer than it is supposed to happen. Rainy season dominated almost the whole 12 seasons in 2010. This prolonged rains have created some problems in nature like floods, interference in food chain and in caterpillars life cycle.
need dryer weather to able to molt from caterpillars into adult insect
but too much water in their surroundings will hinder them from making
The Effect of Weather Disruption.
As it's already been mentioned that extreme weather problem may interrupt insects life cycle. Entomologists (insect experts) say that prolonged rainy season in 2010 up to early 2011 has caused many insects to keep staying in their forms as larva and caterpillars. Those caterpillars naturally consume a lot of food to eat in preparation for the next step of their life cycle when they have to "sleep" as pupas inside cocoons. High food consumption also happens when they grow from larva into bigger caterpillars. The need of much food explains why they forage for food and invade farmers' cultivated plants and anything they can eat.
2. Interrupted Metamorphosis :
Caterpillar is one of the forms in the life cycle of insects or known as metamorphosis. Besides larval or caterpillar stage, there are other three following stages in metamorphosis which are know as pupa, butterfly, and eggs stages. Insects have their life cycle complete if they undergo those four steps in metamorphosis.
Unfortunately complete metamorphosis doesn't always take place successfully, interruption in our season is considered to be one of the factors which interfere the metamorphosis.
3. Interrupted Food Chain.
Birds are insect eaters. As insect predators, their role in natural food chains have controlled the insects population. Lacking or minimizing of bird population caused by bird hunting, vanishing bird habitats, and increasing bird predators, may lead to imbalanced food chain and bring consequence of explosion in caterpillar population like what happens in Probolinggo now days.
4. Insufficient Food Supply.
Prior to caterpillar attack in Probolinggo (latest news says it already spreads to Jombang,another city near Probolinggo), Bromo, a mountain in East Java, has been exploding and still shows its fluctuating activities until now.
Entomologists also give analysis that Bromo eruption has caused insects food supplies around the mountain much decreased and the eruption also brings effect pushing away those insects to migrate to other safer areas with abundant food supply around Bromo. Those creatures, with the help of direction of wind blows, happen to land in Probolinggo and its adjacent cities.
Location of Bromo to Probolinggo and other cities.
Those caterpillars do not stop at those economy plants only, they also invade people's houses and their social facilities like mosque, schools, and office buildings.
I think nobody likes to live closely to those ,annoying and loathing, creatures due to their appearance and effects. Besides economic disturbance, the attack also causes many village residents to suffer from itches,psychological tension, being reluctant to do activities inside homes, and in more serious effect is like a trauma so that they need to be evacuated to a safer place.
How They Solve The Problem.
- Although it's not a preferable method due to its negative impact, but many people including, Sub District Government use insecticide to expel those animals. The use of insecticide in emergency situation like this is understandable as long as it is stopped as soon as the problem is manageable.
- Supply the predators. Birds have been released in the areas which suffer caterpillar attacks.
- Use shaman. East Java people are close to spiritual life that's why they also counter this problem with spiritual approach. Some shamans have been invited to chant prayers which are believed to drive (not to kill) the insects out.
Caterpillar attacks in East Java can be considered as a warning addressed to all of us to treat our environment more wisely. This is a lesson teaching us not to ruin the balance of nature and to conserve the earth more lovingly.