How are cankerworms most readily spread to other trees?

How are cankerworms most readily spread to other trees?

• A. Flying as adults
• B. Hitchhiking on birds
• C. As small larvae blown by the wind
• D. Migrating with the seasons

Answer: (C)

Cankerworms spread mainly because their very small larvae can be carried by air currents from tree to tree. When eggs hatch, these light inchworms crawl onto nearby foliage and twigs, and a breeze can lift or transport them to neighboring trees, leading to quick, local spread. Although adult moths can fly, their movement between trees isn’t as effective for rapid dispersal as wind-blown larvae. Hitchhiking on birds and seasonal migration aren’t typical spread mechanisms for these pests, so the wind-dispersed larvae is the most reliable way they move to new hosts.

Cankerworms spread mainly because their very small larvae can be carried by air currents from tree to tree. When eggs hatch, these light inchworms crawl onto nearby foliage and twigs, and a breeze can lift or transport them to neighboring trees, leading to quick, local spread. Although adult moths can fly, their movement between trees isn’t as effective for rapid dispersal as wind-blown larvae. Hitchhiking on birds and seasonal migration aren’t typical spread mechanisms for these pests, so the wind-dispersed larvae is the most reliable way they move to new hosts.