The study of forensic entomology has been popularized through television and media. Although the pests we encounter within commercial client facilities are not part of a typical criminal investigation, it is equally important to understand what pests are present and the impact they may have. While some pests may simply act as a nuisance, others may present a greater threat to food safety and public health. It is critical to identify the insects at hand to move forward.
Gathering Evidence. While some pests are easily recognizable, others may require analysis from an expert. Entomologists commonly specialize in one type of insect or insect group. Many who serve the food industry are urban entomologists and will concentrate their study on pests commonly found in and around urban environments, such as structurally invading cockroaches. If you cannot identify the pest in-house, it is important to ask your pest management professional or technical expert for help. The collection and gathering of pest evidence can make a difference in whether the entomologist can make the final, specific determination. Damaged specimens can impede proper pest identification. Pest management professionals rely on distinguishing physical features to make identifications, so if the insect is smashed or missing legs, antennae, wings or the head, it may not be possible to identify. To prevent damage, handle the specimen carefully when collecting and gently coax it into a vial or other container. A small paint brush or forceps can help. Insect aspirators are vacuum-like devices that are especially useful when collecting small insects. If possible, collect more than one specimen.
Submitting Evidence. To submit evidence for pest identification, the physical specimen may be mailed to the entomologist, or you can send a photo via email. When emailing a pest identification request, it is important to capture a high-quality image to make identification easier.
There are a few ways to ensure a high-quality photo is captured.
- Get a clear view. The insect must be removed from any bag or vial when taking a photo to enhance the picture quality. If the insect is alive, freeze it prior to photographing it.
- Fill the frame. Fill the photo with more of the insect and less of the background. The entomologist will need to see details, such as the number of legs or antennae segments, for proper identification.
- Keep the insect in focus. In addition to providing a close-up image of the insect, it is important that photos are in focus. If a tripod is not available, steady the camera on a small box or book. Though many smartphones are capable, a camera lens attachment may be beneficial for close-up photos. Camera lenses for cell phones can easily be purchased online through various vendors. There are also digital microscopes that can be purchased that attach to the USB port of your computer. These can be relatively inexpensive as microscopes go and provide superior picture quality. They also facilitate the sending of photos to an entomologist. The scope allows you to snap a picture and download onto your computer for sending. Celestron and Dino Lite are just two of the brands available.
- Add an object for reference. Size can be an important detail in identification. Adding a ruler, coin or pen tip in the photo can help the identifier perceive the pest’s size.
- Include all angles. Different features are used to identify various insects, so photos may need to be taken from multiple angles to capture all characteristics. If the initial photos do not allow for identification, the specimen may need to be mailed or more photos may be required, ultimately delaying the identification process.
- Consider contrast and lighting. Photograph the specimen in a well-lit area. The entomologist may need to look at select features that are dark in color like the veins on the wings, and photographing the insect on a light-colored surface can help features stand out. Use the camera flash or other supplemental lighting as needed.
- Include details with the photos. When sending in identification photos, include where the pest was captured, if any products were infested or damage was caused and any other information that may assist with the identification.
Retain the pest samples after the photos are submitted in case additional pictures are requested or the entomologist asks to see the physical specimen. In some cases, another specialist may be enlisted for identification assistance, and they must have access to the sample. If the insect is being mailed, package it properly to minimize damage. Except for butterflies and moths, placing the specimen in a vial with isopropyl alcohol (at least 70%) is recommended since it can help preserve it. Include the same information outlined above, including where the pest was found, any damage it caused and the contact person for the findings. It is also important to indicate whether the specimen must be returned.