There are some basic questions that must be answered to determine the probable effectiveness of the Sterile Insect Technique with a given species and in a given area before it is implemented. Those questions include: Read more... (458 words, estimated 1:50 mins reading time)
- Is there an effective and reasonable economic method of mass rearing the target insect?
- Can the released insect rapidly disperse through the wild population?
- Will sterilization affect mating competitiveness? (i.e., will sterile males be able to compete with native males and win mates?)
- Is it possible to achieve effective over-flooding ratios with sterile insects over the wild pest population?
One of most commonly asked questions is whether sterile insects used in the Sterile Insect Technique are radioactive. It’s a valid question.
It is important to note that there is a general misunderstanding of the difference between irradiation and radioactive contamination, or radioactivity. Insects used as part of the Sterile Insect Technique are irradiated. Irradiation occurs when something is exposed to energy such as microwaves, x-rays, gamma rays or light. Contamination occurs when a source of radiation is transferred. Microwaved food, a person who has had an x-ray, or a sterilized moth are not contaminated by radiation since they do not contain the ionizing radiation source. Insects sterilized with gamma rays (used with the SIT) are thus not made radioactive in a way that could be harmful to other organisms. Read more... (260 words, estimated 1:02 mins reading time)
Now that you’ve read a little about the Sterile Insect Technique itself, you may be wondering how it works. How does one rear and release thousands, or even millions, of sterile insects? What makes them sterile? How do we know the insects are doing their job?
Let’s start from the beginning. The Sterile Insect Technique involves three basic stages: mass rearing of the insect pest; sterilization of reared insects; and release of sterilized insects into infested areas. The Moss Landing facility has been set up to rear enough light brown apple moths to determine the best method of implementing the SIT: the best method to rear the moths, to evaluate them and see how the sterilized insects are performing. Read more... (502 words, estimated 2:00 mins reading time)
Sterile Medfly Quality Control. Photo courtesy Mike Arbogast, USDA.
I wrote a blog entry a few months ago about invasive pests in San Diego County, focusing on Medfly because quarantine was in place in the Mira Mesa area. Well, we recently had new Medfly detections in Fallbrook and now have an active treatment program underway.
Two adult male flies were detected in one trap on October 29 and a mated female fly in another trap on November 1. Fallbrook is in northern San Diego County, an area known for its agriculture. The treatment plan includes using the Sterile Insect Technique, fruit stripping from trees within 100 meters of the infested sites and applying an insecticide developed from naturally occurring bacteria to foliage within one-eighth mile of the infested sites so any adult Medflies will feed on it and die. Read more... (381 words, 2 images, estimated 1:31 mins reading time)
Many people hear “Sterile Insect Technique,” or SIT, and wonder what it is. It’s a good question—the name itself doesn’t explain what SIT is or its purpose. So allow me to explain…
But before I explain, some background on me: I am an entomologist and have spent my career conducting research on both biological control for agricultural pests and the SIT. I’ve worked on programs for several pest species of insects, including the silverleaf whitefly, pink bollworm moth, screwworm fly, glassy-winged sharpshooter and light brown apple moth. Read more... (517 words, estimated 2:04 mins reading time)
Author: Dr. Gregory Simmons, Light Brown Apple Moth Coordinator, USDA | Tags: