By John Schepis
SIT and Public Perception
The Sterile Insect Technique (SIT) has received increased attention over the past year due to the expansion of SIT programs and its role in controlling insects of public health importance. The method uses laboratory-reared, sterilized male insects released into targeted areas to suppress or collapse local populations. The strategy is used in certain areas throughout the US, particularly in southern coastal states, to combat mosquitoes, especially where mosquito-borne illnesses are a concern. With the recent reinvasion of the New World screwworm into Texas, SIT has been selected as the principal strategy of control, and the United States Department of Agriculture (USDA) has committed to building a $750 million facility to produce sterile male insects. Google’s parent company Alphabet has even shifted attention towards SIT with plans to get EPA approval to release sterilized male mosquitoes to reduce disease-spreading mosquitoes. Talk and attention towards SIT is likely to continue as these programs expand.
To some members of the public, manipulating pest populations through SIT may raise safety concerns. Recent attention also has made SIT appear like a new, unvetted technology, but the truth is that SIT has been around for a long time. The process was first studied in the late 1930s, and government programs using the technology became established during the 1950s and 1960s. Once developed for a target species, sterilization protocols are highly effective. For certain species and in the right scenarios, SIT was found to be a highly effective non-chemical control method, and the strategy fits well into modern Integrated Pest Management (IPM) programs.
Advantages and Limitations of SIT
SIT uses ionizing radiation in the form of X-rays or gamma rays to sterilize male pupae or adults and is highly effective at appropriate doses. Irradiation causes insects to be more sluggish and less suitable mates, making mass production an important factor in SIT. Following sterilization, the insects are released from the ground or through aerial methods. Sterilizing and releasing females does not have a positive effect on control results. The method requires breeding/irradiating facilities to create the sterile insects for release, and it is only practical for species that are easily determined by sex, can be mass-reared, and irradiated easily. SIT is best for species that are monogamous, such as the New World screwworm.
Source : illinois.edu