Furry Moths Invade Northern Venezuela

An explosion in the population of a moth species, fomented by Hurricane Ivan last month, has triggered allergic reactions in at least 3,000 Venezuelans.

CARACAS - Thousands of residents in Venezuela's northeastern coastal villages seek refuge in their homes at nightfall. They close the doors and windows, turn off the lights, and even pray for salvation from a plague of hairy moths, the Hylesia metabus, which are attracted to light and leave a wake of allergic reactions.

Already some 3,000 people have been affected by allergic reactions to the tiny hairs -- or setae -- that come off the bodies of the moths, according to reports from health centers in Sucre, Delta, Amacuro and Monagas states.

''These are insects measuring about five centimeters, brown, whose adult life -- in which they actively release the harmful hairs -- lasts one week. Each female can produce up to 400 eggs,'' researcher Frances Osborn, of the Venezuelan Universidad de Oriente, told Tierramérica.

The Hylesia genre of moths ''is neotropical, native to the Americas, ranging from the United States to Argentina, while the metabus species is found in eastern Venezuela and the neighboring Guyanas. It inhabits mangroves, particularly the red mangrove,'' said Osborn.

Health reports for recent decades indicate numerous cases of epidemic dermatitis caused by the Hylesia in Argentina, Brazil, the southern United States, Mexico and Peru.

In Venezuela, the first reports of allergies to this furry moth date to the late 1930s, when the crews of oil tankers were affected and, when they received treatment, were diagnosed with ''papillonite'' (named for ''papillon'', or butterfly, in French). The name originated in French Guyana.

Strong winds generated by Hurricane Ivan, which passed near Venezuela's Caribbean coast in September, carried the moth larvae from isolated mangrove forests to populated areas.

The Hylesia metabus spread first through the towns of the Gulf of Paria, which separates Venezuela from Trinidad, and this month reached Caripito, 100 km from the coast and home to several thousand people.

With the spread of the moths came allergic reactions, including hives, conjunctivitis, headaches and other reactions, varying in intensity, depending on the individual's sensitivity. ''Children are the most vulnerable because of their sensitive skin,'' said Osborn.

''Not all of the moths hatch at the same time and their life cycle lasts three months, so the problem is prolonged,'' a health ministry official told Tierramérica.

Once the larval phase -- lasting some 58 days -- is complete, and the moth enters its adult phase, females begin to release hairs to protect their eggs.

The concentration of lights in towns and villages attracts more moths to populated areas.

''All socioeconomic activities have been affected, because as soon as night falls, people avoid turning on lights in their homes -- even opening refrigerators -- so they won't attract the moths. Businesses have been forced to close their doors earlier, and that has caused important economic losses,'' said the health official after visiting the area.

Health centers report allergic reactions such as severe inflammations that look like magnified mosquito bites, particularly on the neck and arms.

Medical treatment entails antihistamines to counteract the effects triggered by the moth setae, said Carlos Villalobos, director of environmental health for Fundasalud, an institute in Sucre.

Many villagers opt for home remedies, including compresses of vinegar and camphor to reduce the burning and itching sensation. This improvised remedy also creates a protective layer over the skin, protecting it from the allergic effects of the moth hairs.

''The hive-inducing proteins of the hairs are inhibited a bit upon contact with the acids of those substances, but we are still engaged in studies to determine concrete results,'' said Osborn.

While the experts continue their studies, officials are enacting health measures, such as installing ''light traps'' on town lampposts to attract the moths. The traps contain the moth hairs.

Other efforts include aerial fumigation, using organic substances, but also high-pressure gasoil spraying where there are heavy concentrations of the moths.

Every day, 9,000 liters of gasoil and 15,000 liters of insecticide are applied, at a cost estimated to reach ''some 260,000 dollars over the period of these operations,'' which could last three weeks, said Fundasalud's Villalobos.

* Yensi Rivero is a Tierramérica contributor.