Gypsy moth infestation to continue until September


The ongoing infestation of Lymantria dispar, commonly known as the gypsy moth, will continue until September 1, according to B.Ganzorig, the Head of Forest Protection, Breeding, and Restoration at the Forest Research and Development Center. The population of gypsy moth will reach peak around August 10. B.Ganzorig gave an interview regarding the movement of the gypsy moth.

You have said in the past that the gypsy moth is one of the most persistent pests in Mongolia. How damaging are they?

Yes, internationally they are recognized as gypsy moth. The species fly around looking for one another. It is a moth that particularly likes light during the night. Therefore, they are more likely to gather in a place with lights. Once they find one another, they mate, at which point they are not particularly harmful to humans.

There is, however, danger when they lay eggs in creases and crevices of homes.
If a moth has laid eggs, it is best to clean it up before they hatch. After laying their eggs, the gypsy moth dies a natural death.

Are there any steps being taken to exterminate gypsy moths?
We are conducting extermination with money delegated from the state budget. Due to the dry weather conditions, the spread of the moth has increased. In green zones of the city and at Nairamdal Children’s Camp, extermination companies are currently working. We will be conducting extermination near the summer houses in the outskirts of the city. However, it is hard to work in areas with a lot of summer houses. The reason is that there are many people living near mountain valleys and it would only be detrimental to their health, it would disturb their peace to start spraying pesticides on top of their houses with a plane.

In rural areas, there are a large number of gypsy moths in Sharyn Gol, Mandal and Eruu soum of Selenge Province and Batsumer soum of Tuv Province. Also in Khutag-Undur and Teshigt soums of Bulgan Province, and Khangal soum of Orkhon Province has reported outbreaks of gypsy moths.

In order to prevent the spread of gypsy moths, it is advisable to lure them with a bright light and trap them in a bag. Their mating season will intensify beginning in early August, continuing up until early September. Once the eggs are laid and they hatch the next year, they damage forests very dramatically.

Can you give us brief information about the life cycle of a gypsy moth? At what stage is the moth dangerous?
Researchers divide the pest into two categories, developed and underdeveloped. The gypsy moths that are flying right now are fully developed and have passed four stages of development. These four stages take about a year in total.

The first stage is getting through winter. They begin to hatch around late
May and become larvae. The larvae will first feed on leaf hairs and then move onto the leaf epidermis.

The larvae reach maturity between mid-June and early July, then enter the pupal stage, during which larvae change into adult moths.

The gypsy moth causes the most damage during its pupal stage. They do not only eat one type of tree, they consumer around 300 types of tree leaves. They can feed off of any plant if necessary.

How much damage did gypsy moths cause to the environment during its larvae stage?
There is around 560,000 hectares of land that need to be addressed. Around 50 percent or 300,000 hectares of land have been determined to be moth hotspots. If we are able to decrease their numbers significantly, the health of trees will improve by next year.

The moths lay their eggs everywhere. What is the success rate of their egg-hatching?
In a laboratory setting, the success rate of hatching is 100 percent. In the wild, their chances are around 80 to 90 percent, seeing as they are resilient animals as
products of nature.

Does that mean eggs laid indoors will hatch?
Yes, they will hatch. When found, eggs need to be buried immediately or burned. People do not realize that eggs have been laid the previous year and are hatch the following year. Homeowners need to take appropriate measures on their own to prevent outbreaks.

Say we are able to exterminate all the moths flying in the open; there are still millions in the forests. How will you exterminate the eggs in the forests?
We have drafted a plan. Even if we are not able to exterminate them completely, we will exterminate around 50 to 60 percent of them. We are taking every measure to prevent the movement of gypsy moths into Ulaanbaatar.

Is it true that gypsy moths release allergens?
When gypsy moths rub their bodies or wings, it releases allergens. It might cause coughing and sneezing similar to an allergy. I would advise people to turn off their lights at night in order to not attract any swarm of gypsy moths.

Can you quantify the spread of the moths?
The Forest Research and Development Center conducted a study in 73 soums of 12 provinces. Based on the study, in 1.4 million hectares of land, there are 158,100 hectares with gypsy moth outbreaks. Out of 150,000 hectares of land affected by the outbreaks, 60 percent has been addressed.


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