The team from the Biodiversity, Coastal, Wetlands and Ecotourism Research Center–Department of Environment and Natural Resources Region VI (BCWERC-DENR 6) assessed the approximately 2 - hectare mangrove area which was detected to be infested by the larva of ‘tide watching mangrove moth’ last November 12, 2015 in Brgy. Loboc, La Paz, Iloilo City.
As observed, the worms were feeding on the Avicennia species’ leaves causing a considerable number of mangrove trees to dry up and turn brown. The pupa of ‘tide watching mangrove moth,’ Aucha velans were found on dried wrinkled leaves of the mangroves, particularly the Avicennia species.
The team gathered pupa samples to be observed and examined. It was found that this type of pest is of the same kind which infested the mangroves in the seven coastal towns of Capiz up to Batan, Aklan last 2008 and in the coastal towns of Negros Occidental in 2009. Similar infestations were also discovered in Anilao, Iloilo River and Brgy. Hinactacan, Lapaz Iloilo City in September 2010.
After five years, another infestation occurred in the city of Iloilo at Brgy. Loboc, La Paz. According to Neil G. Gigare, Science Research Specialist, these worms might spread in the mangrove areas in Iloilo River from Luna, Lapaz and Iloilo Esplanade. At present, infestations were already observed in the coastal areas of Banate, Barotac Viejo and Ajuy, Iloilo but were not yet assessed.
The adult moth has an average life span of seven days, and within three days it has to mate and reproduce. An hour after mating, the male moth dies while the female moth will lay eggs in a matter of hours. When the eggs hatch, the larva or worm feeds on the mangrove leaves. These pests will quickly spread and infest other mangroves especially in their larval stage. However, mangroves are tough enough to withstand these pests since they are only defoliators. There is a big chance that they can survive on their own that is why cutting down of affected trees are highly discouraged. The use of insecticides in eliminating these worms is also highly discouraged because the chemicals will affect other organisms thriving in the mangroves. Mangroves are trees and shrubs that grow in saline coastal habitats and serve as breeding grounds of marine life. They have been found to clean bodies of water, help in taking carbon out of the circulation and act as coastal shields in times of abnormal rise in sea level and powerful tides in times of typhoon. Lyn Florence B. Palma, BCWERC