yearworm

A yearworm is a colloquial term used in some regions to describe a type of animal behavior, rather than a specific species. It generally refers to a caterpillar or larva that exhibits prolonged developmental stages, often appearing to "overwinter" or persist for an unusually long time before pupating or metamorphosing. This extended life cycle is typically an adaptation to environmental conditions, such as cold climates where the growing season is short, or areas with unpredictable food availability.

The term "yearworm" is not a scientifically recognized classification. Instead, it's a descriptive phrase used by observers to note the longevity of a particular larval stage. The actual species involved can vary widely, including moths, butterflies, or other insect groups that have adapted their life cycles to survive for an extended period, sometimes spanning over a year, in their larval form. This extended duration allows them to maximize feeding opportunities when conditions are favorable and endure unfavorable periods in a dormant or semi-dormant state. The visible presence of these "yearworms" often coincides with specific seasons when they are most active or emerging from their prolonged stage.