Southwestern Region

FOREST HEALTH: Tiger Moth Activity in the Region

If you are seeing tents like this in the forest trees for the second year in a row, they are formed by tiger moths. Tiger moths, (Lophocampa ingens (Edwards), also called Halisidota ingens) are medium sized tan moths with beige spots on their forewings. Populations are generally kept low by natural enemies and cold winters. Recently there has been more tiger moth activity observed in the region. The caterpillars mainly form their large silken webs in the upper branches of ponderosa and piñon pine, but can sometimes be found on other species when there is an outbreak.

There is only one generation per year. The eggs are laid in August, caterpillars hatch in September and October and they form webbing and begin to feed. These webs remain small and unnoticeable until feeding resumes in late winter or spring and their webs are expanded. Pupation occurs in June and adult moths emerge in August to restart the cycle.

Permanent damage to the tree rarely occurs. If you have a tent on a landscape tree, it can be removed by cutting the tent out of the tree and disposing of it. CAUTION: Some people are allergic to the caterpillar hairs. HANDLE WITH CARE!

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