Nematodes that ride insects: Unforeseen consequences of arriving species

Abstract

Insects that arrive in new regions can be hosts for a variety of unseen metazoans, including microscopic nematodes, which are carried phoretically as dauer juveniles or as internal/ external parasites in various stages. This includes insects that arrived by natural means, were purposefully introduced for biological control before strict APHIS/PPQ provisions, were inadvertently introduced as hitchhikers or stowaways, or were brought in as part of the pet trade or for food. In some cases, the host associations are so specific that they may pose little threat, but in other cases where host specificity is relatively wide and/or host transfer opportunities exist, the nematode associates can expand, colonize and establish associations with native insects causing various downstream environmental effects. Because nematodes are mostly microscopic, the consequences of such introductions are usually not considered in the pet trade or as an added consequence as introduced or invasive insects arrive in the state and establish themselves. These arrival scenarios are discussed with real-world examples, including one with damage potential for Florida and the southeastern U.S., i.e. the red ring nematode that is associated with palm weevils.