Insect Identification


Insect and Other Pest Identification

A Madagascar hissing cockroach

Is something bugging you? Bring a sample by the District office anytime we’re open. The laboratory staff will attempt to identify your sample and, if possible, provide information on resolving your pest issue.

To increase the likelihood that our staff will be able to identify your sample, please:

  • contain your sample in a closed vial, jar, bag, or other container
  • avoid damaging the sample if possible
  • bring the sample to the office promptly before decomposition begins
  • note when and where you collected the sample, and whether it bit or stung anyone
  • samples on adhesive monitoring traps for mites, bedbugs, and fleas are also ok

In some cases, it may be possible to identify insects and arthropods from photos. You may email photos to For best results taking bug photos, please read this first. You may want to save the sample in case your specimen cannot be identified from your photo.


Specimen Submission Guidelines

The District laboratory staff will do their best to promptly identify resident-submitted samples promptly, but there may be delays during times of heavy workload or when there are multiple or frequent sample submissions.

San Mateo County Mosquito and Vector Control District is not a medical facility and does not accept the following items for insect identification: undergarments, diapers, skin or tissue samples, items containing or contaminated with bodily fluids (such as nasal excretions, ear wax, spit, semen, urine, vaginal excretions, blood, and others), excrement (animal or human), or hair samples. If you believe you have insects in your body and believe an evaluation of your bodily fluids is required, please contact your physician or other medical care personnel.


Special Instructions for Tick Identification

The District laboratory CANNOT test resident-submitted ticks for Lyme disease or other pathogens. If you are bitten by a tick and would like to have the tick tested, please make sure that the tick remains alive and is contained in a slightly humid environment like a small jar or a plastic bag containing a moist piece of paper towel.Ticks can be brought to the District office for identification only or submitted to the County Health Laboratory, located at 225 West 37th Street, Room 113, San Mateo, California for testing.


How to Collect Samples for Identification

Larger insect specimens can be collected in a jar or other container with a tight-fitting lid. If you prefer not to touch the insect, you can use a piece of cardboard and a container to capture your specimen. Specimens can also be submitted in plastic bags, but please be sure not to crush or squash your specimen. Please ensure that the container or bag is tightly sealed so that your insect, if alive, can’t escape.


How to Identify Insects Yourself

If you’re simply curious about an insect you’ve found, you may want to try to identify it yourself. Here are some things to look for:

  • Size
  • Habitat – was it outdoors or indoors? what time of day did you see it? what type of plants were nearby?
  • Behavior – did it walk, jump, or fly? did it move quickly or slowly? did it bite or sting someone? was it feeding on a plant or something else?
  • Appearance – how many legs did it have (hint: insects should always have six)? how was its body shaped? did it have wings? what color or pattern was it?
A dead mosquito on a white background.
Blog post

Tips for Taking Detailed Insect Photos

Since we started reaching out to the public about reporting suspected invasive Aedes mosquito sightings, we’ve gotten a lot of mosquito photos in our email! That’s great, but insects - especially mosquitoes – are pretty small and they can be hard to identify in photos.