Western Tussock Moth Caterpillars in Flood Park this Spring/Summer

Flood Park is currently experiencing an infestation of the Western Tussock Moth. These moths, in their caterpillar phase, eat large amounts of foliage and cause general nuisance.

The infestation is temporary. The caterpillars' presence will be most noticeable in late April/early May. While the caterpillars are feeding and for a time after, trees throughout the park may appear sick or dead with damaged or missing foliage. By July the caterpillars will have transformed into moths and cause less of a disruption. Some trees affected by the infestation may regrow foliage quickly while others remain dormant until next growing season. For the majority of Flood Park's healthy, established trees, there should be no major long-term damage.

Avoid touching Western Tussock Moth caterpillars, as their hairs may cause irritation to skin. Caterpillars and their droppings may fall from trees onto picnic sites and paths. The prevalence of this pest is unrelated to the recent park renovations.

For more information about this species see the University of California Pest Notes on the Western Tussock Moth.