>But the tiny parasitic wasp H. horticola appears to have been able to fly or at least to be lifted by strong winds to move between islands on the Åland archipe

>But the tiny parasitic wasp H. horticola appears to have been able to fly or at least to be lifted by strong winds to move between islands on the Åland archipelago When I did agronomy work in Kansas, there were some pests like aphids (and fungal diseases) that are normally unable to overwinter. Somehow they get blown up high into the air and moved around by jet streams to be dropped hundreds of miles north, where they can become an economic pest but not technically able to complete their life cycle into the next year. This especially works well with aphids, as part of their lifecycle is making clones of themselves, so just one is needed to cause a local infestation. Often these carry viruses, and the initial effect is random spots of disease showing up in the middle of a field. For pests that migrate under wing power, they tend to initially establish on field edges first and slowly move in. https://www.sciencedirect.com/science/article/abs/pii/S0168192306001407 https://www.sciencedirect.com/science/article/abs/pii/S01681...