Nature has a way of keeping things in order with checks and balances. When an organism dominates or overpopulates an area it will eventually be knocked back down through predation, resource imitations, or disease. Insects will readily explode their populations when conditions are favorable. In pest control we see this quite frequently with German cockroaches and bed bugs. These insects get into our houses which are protected, climate-controlled environments with almost no natural predators (save the occasional spider or house centipede). As long as they have plenty of available nutrients they will continue to reproduce and grow their numbers until something drastic happens, which is usually an extensive treatment by a pest professional.
We see this happen on a large scale as well when an insect is introduced (accidentally or purposely) into an area they have never been before. When this happens the balance of nature can be offset and, without the presence of their natural enemies, these insects can exploit the situation and cause lots of havoc. For the most part our border inspection agencies (like APHIS) do a good job in keeping invasive insects at bay but unfortunately some still manage to sneak by.
Not to single out a particular region, but it does seem like many of our problematic invasive insect pests have come from Asia as of late. The following is an incomplete list of some of the invasive insects from Asia that are currently causing problems in the U.S:
- Asian citrus psyllid: Damages citrus plants causing a decline in citrus production.
- Asian cockroach: Identical in appearance to the German cockroach but infests mulch and pine straw around structures and fly to lights at night causing a general
- Asian lady beetle: Beneficial insects that feed on crop pests, but are a nuisance when they overwinter inside structures.
- Asian long-horned beetle: Destructive wood boring pest of maple and other hardwood trees.
- Asian needle ant: Nuisance ant that has a painful sting.
- Asian tiger mosquito: A daytime biting species that vectors diseases such as West Nile Virus and Chickengunya.
- Brown marmorated stink bug: Feeds on fruits and vegetables and overwinters inside structures.
- Chili thrips: Attacks over 100 crops, including chili peppers, tea, strawberries, and tomatoes, resulting in defoliation and crop loss.
- Emerald Ash borer: Kills many tree species very quickly.
- Formosan subterranean termite: Very destructive structural pest.
- Hemlock woolly adelgid: Destroys Eastern Hemlock trees.
- Khapra beetle: Destructive pest of grain products and seeds.
- Kudzu bug: Damages soybeans and other legume crops, overwinters inside structures.
- Oriental fruit fly: Destructive pest of fruits and vegetables.
- Pink bollworm: Damages cotton plants.
- Pink Hibiscus mealybug: Destroys crops and ornamental plants.
Certainly not all of our problematic invasive insects have come from Asia. Two of the most difficult pest ants (Red Imported Fire Ants & Argentine Ants) we have to contend with are from Argentina in South America. But don’t fret, several countries in Asia in turn have to deal with invasive insects from North America so it goes both ways. Some of these are destructive plant pests such as the silverleaf whitefly, greenhouse whitefly, Western flower thrips, vegetable leaf miner, fall webworm, Florida mining fly, and ragweed beetle. We have also given them the Tropical fire ant which is indigenous to the Southern U.S.
As humans continue to travel around the world and increase international commerce, we will always have to deal with critters hitchhiking rides and ending up in foreign areas. As long as the climate is favorable and the resources are available, they will be able to proliferate especially without having what naturally keeps them in check. They can overpopulate areas, displace native species, and generally upset the natural balance of the ecosystem. Not unlike us!