Pacific Tent Caterpillar
Malacosoma constricta

Malacosoma constricta, also known as the Pacific tent caterpillar, is a species of moth endemic to North America. Malacosoma constricta is known from California, Oregon, and Washington and is reported only on oaks. In California, subspecies M. constrictum austrinum is found from Santa Barbara County southward; M. constrictum constrictum occurs from Los Angeles County northward. Source
Where it is now
No records in the last 8 weeks. It may be out of season where the observers and sensors are.
See the Pacific Tent Caterpillar on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| North America | 16 March 2026 | 16 March 2026 | 30 March 2026 | 1 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.