Aliens among us!

Alien Ants in Northern Thailand

A new project QSBG Entomology has recently started is a project examining 'alien ants' (also know as 'tramp ants'), their impacts and some aspect of their management in national parks in Northern Thailand. These ants are not the sort of aliens from outer-space but are just ants that have been introduced to an area where they are not native -- alien to that area. Alien ants are one of the most important insect alien invasive species with many reported impacts on environments, agriculture and even human health.

One of the most well know cases of impacts from alien ants is the invasion of Christmas Island by "Yellow Crazy Ants" (Anoplolepis gracilipes). The invasion of these ants has had a large impact (death and displacement from habitat) of the iconic "Red Land Crab". These crabs have a key role in the ecology of Christmas Island where they are major consumers of seedlings and leaf litter, their displacement leading to dramatic changes in the vegetation structure. Besides these direct effects Yellow Crazy Ants have an association with Scale insects, such that in areas with hingh numbers of ants there are also high number of scale insects and this is in turn associated with 'Sooty Mold', these stresses leading to canopy dieback and invasion of weeds. As well as having a scary name these ants are exemplary of the dangers of alien ant species.

The well known dangers of alien ants lead to the Entomology unit of the the National Parks, Wildlife and Plant Conservation to conduct a widespread survey to document the incidence of alien ants in Thai National Parks. They found 8 species of alien ants in 21 of the 22 parks that they surveyed. Our project follows up on this issue with an examination of some additional national parks, looking at seasonal differences and examining the extent of the penetration of alien ants into 'undisturbed forest' and the impacts upon native species.

Below are see a few snapshots from some of our field work this year.

Mae Hong Son
Mae Hong Son has several of our field sites. Are there aliens in those mountains?
Wichai (project leader) anchoring a transect
Our project leader anchoring a transect for a trapline that will run into the forest
Raewat digging in a pitfall trap
Raewat digging in a pitfall trap
Start of a transect proceeding from an area with much human disturbance
Start of a transect proceeding from an area with much human disturbance
Even in the dry season or pitfalls have a roof-not so much to protect from the rain but as a good control
Even in the dry season our pitfalls have a roof-not so much to protect from the rain but as a good control