Insect sniffing the way of the future

Insect sniffing the way of the future

Ever since hearing about the potential to use insects as a form on chemical detection, like canines are used for, I have been fascinated by the potential. Imagine going to the airport as your about to go away on holiday, and there are bee’s flying around the place, or people walking around with some wasps in a bottle, trying to find the next terrorist bomb or drug run before it happens.

The article I have chosen to write this post about was “Using insect sniffing for detection” by Glen C. Rains, Jeffery K. Tomberlin and Don Kulasiri.

The first such studies into using insects as a means of detection were developed, like most technologies, in the United States Army in 1963. These studies were aimed at using the innate behaviour of insects to detect the presence of an enemy. Human feeding insects like mosquitos, ticks and lice. These insects have a hardwired behavioural response to changes in CO2 or lactic acid concentrations in the air, which could signal human presence, like an enemy.

Although most insects learn through their natural habitats, or from parents, some can be taught behaviours, or have they modified. A chemical or volatile that is unrecognizable to an insect can be taught to be recognizable by teaching the insect to associate it with food, or a host like for parasitoid wasps. The animals behavioural response when it senses the smell (thinks its sensing food or a host) can then be analysed to find out where or what the chemical is.

 

http://forensicentomology.tamu.edu/pdf/Final_draft_Grains_et_al2008.pdf

There are several different methods that can be used for detection using insects. Free-moving detectors use insects that have been trained to detect a specific substance. These insects will then move towards the source of the substance, and can be tracked using tiny antennae on the insect (usually honeybees).

 

http://forensicentomology.tamu.edu/pdf/Final_draft_Grains_et_al2008.pdf

Another method for using insects for detection is using restrained organisms. These devices use a number of insects trained to detect a specific chemical, and are sometimes combined with some control insects so that the trained insect’s changes in behaviour are more noticeable, and the validity of their detection is augmented. The changes in the insects behaviour are then observed and analysed by webcam, either by entomologists, or computer software currently being developed. There is also another type of detection device which used a voltmeter to detect spikes in the signal from feeding muscles of moths as they start to use these muscles more as they think they have sensed food.

There are numerous advantages for using insects as a bio detection method. Insects can be trained extremely quickly, from within minutes, to only a few days for some honeybees. They can also be trained to be chemical specific. They are extremely cheap to train, especially compared to sniffer dogs, and there is also less controversy towards using insect detectors in potentially toxic environments compared to using dogs. Insects have also been proven to be excellent at detecting chemicals in complex chemical rich environments, and are also more sensitive than dogs in some cases.

There are several problems with using insects for detection. Variability between individual insects could lead to false detections, or varied results. Artificial selection may help to eradicate these over time though. There are also several ethical problems. These detection devices starve the insects before using them as this makes them better at sensing what they think is food. The insects are also kept in restrained positions and in small containers. To the majority of people, these seem of no consequence, as they are ‘only insects’, but to some, myself included (I think), this is quite immoral.

More research is needed in order for these systems to become mainstream; however there is huge potential in them. Future applications for these bio detection systems include fire detection, medical diagnoses, aflatoxin detection in peanuts, grain and milk, illegal drugs, arson and explosives. There are some insects that can already be naturally utilized, such as blow flies and females hide beetles which are adapted in finding decomposing remains like humans. The Jewel beetle Melanophila acuminate can detect smouldering wood from over several miles, which would be a valuable device is detecting wild fires early.

I find this an exciting branch of entomology, and one that has a huge future. I hope you guys found this as interesting as I did.

 

LAND where you want to be,

 

Nick