Tramp species

The term was coined by William Morton Wheeler in the bulletin of the American Museum of Natural History in 1906, used to describe ants that “have made their way as well known tramps or stow-aways [sic] to many islands".

Tramp species have been noted in multiple phyla spanning both animal and plant kingdoms, including but not limited to arthropods, mollusca, bryophytes, and pteridophytes.

[6] For example, Anoplolepis gracilipes was able to invade undisturbed forest ecosystems in Australia after being introduced and having an established population in northeast Arnhem Land.

[5][10][11][12][8][13][6][4] As such, they are almost always present in urban or human-settled environments, and have colonizing mechanisms that are well adapted to human cohabitation,[13] referred to as possessing "anthropogenically reinforced dispersal biology".

[5] These often repeated introductions (as oftentimes shipments will come from the same place) contribute to fortifying the genetic variability and initial population sizes of newly transplanted tramp species, which facilitates their establishment in novel environments.

Anthropogenic forces (such as construction and agriculture) can dramatically impact local fauna and flora, weakening the environment and making the area more susceptible to the encroachment of tramp species.

[5] As many tramp species are well adapted to disturbances in their native habitat, they are particularly resilient to large-scale, unpredictable weather events (such as floods, wildfires and monsoons), which are set to increase in frequency as anthropogenic activity continues to affect global systems.

[9] Both of these venomous species have been known to bite humans, often times causing severe anaphylactic reactions; this has made them known public health hazards in the regions they are found.

[11] Direct pest management efforts have included baits with insect growth regulators to sterilize colonies to varying degrees of success.