Living in peace with stinging and biting insects

In Québec, stinging and biting insects like mosquitoes, midges, black flies and horseflies are impossible to avoid in the summer season. A lot of people would like to get rid of all them, but are there solutions for living in peace with them while having the least possible environmental impact?

Some discomforts not to be overlooked

First of all, let’s remember that stinging and biting insects are especially attracted by the carbon dioxide produced by our breathing, as well as by the smell of our sweat and the microbiome of our skin.1 Apart from the pathogens transmitted, some people have strong immune responses to arthropod stings or bites. That said, concern about stinging and biting insects also has to do with our individual comfort, not a factor to be underestimated...

A range of tools for escaping insects

An impressive range of tools has been invented for helping us avoid these insects. They can be divided into two categories: the ones that are installed in the environment, and those that we wear on our own selves. The environmental devices include insect killers that act as traps: they attract insects and eliminate them. The first patented design used light as the attractant, and a wire mesh on which unsuspecting insects electrocuted themselves. Are these “bug zappers” effective? Researchers have observed no significant difference between the bite rate in yards equipped with these devices and in yards that aren’t.2 In fact, stinging and biting insects aren’t especially attracted by light, and account for just a tiny fraction of the insects killed by those traps.3 And yet, despite their long-documented ineffectiveness, a number of devices using that technology are still being sold.

The other devices, conversely, seek to keep insects away – by releasing either smoke or natural or synthetic repellants. Those same molecules can be applied directly on the skin to help prevent bites and stings. However, they have to be applied at regular intervals for optimum protection. Those molecules act by blurring the olfactory reference points that stinging and biting insects use to find us. Here are two examples:

• diethyltoluamide (DEET)

DEET is the active ingredient in a number of commercial topical repellants. It’s got proven effectiveness, to the point that its use is recommended by Health Canada (information on human biomonitoring of DEET), and is safe when used as recommended. Serious side effects are extremely rare. Accidental ingestion (notably through food contamination) or excessive application on the skin may result in a range of symptoms. Applying the product on children younger than six months old is not recommended. For those between six months and two years old, use a product containing less than 10 percent DEET, in small quantities and no more than once a day.

• Essential oils

A number of plants naturally produce repellant compounds like alkaloids and terpenoids. Of these, essential oil of citronella (Cymbopogon citratus) and a combination of oils of eucalyptus (Eucalyptus spp.) and basil (Ocimum basilicum) have proved to be effective in repelling certain mosquito species when applied to the skin.4

Collateral damage

Like insect traps, repellant methods can also have negative consequences for other animals, and even on human health. Whether they’re released by some device on the patio or applied to our clothes or the fur of our companion animals, insect repellants wind up in the environment. And while most of them break down quickly, traces can still be found in certain habitats, particularly aquatic ones, as well as in more unexpected spots, like birds’ nests.5 As a precaution, should we maybe not confine their use to when they’re strictly necessary?

Low-impact but effective tips

Here’s some advice for better coexistence with stinging and biting insects:

• Slow down the development of life cycles

To reduce the reproduction of insects that feed on blood (hematophagous insects), their access to egg-laying sites has to be restricted. Many objects in our daily lives that contain stagnant water provide microhabitats for mosquito larvae: watering cans, children’s toys, tires and so on. Don’t forget to empty and store those accessories after using them.

• Install physical barriers

Even though it’s both impossible and undesirable to eliminate all egg-laying sites, some solutions make it possible to limit contact. Installing screens in different places (windows, gazebos, tents) is a good strategy. You can put a fan on the patio to keep insects away. Also, wear long, thick clothing to reduce insects’ direct access to the skin.

• Apply repellants properly

As mentioned earlier, applying certain essential oils protects against some mosquitos. And as for DEET, it can be used sparingly

Without trivializing the impact of blood-sucking insects on society, let’s not forget that they’re an important link in the food chain, in addition to being pollinators and in certain cases contributors to water quality.

Finally, the question arises: can we agree to share nature with insects...all insects?

References

1. V. Coutinho-Abreu, O. Jamshidi, R. Raban, K. Atabakhsh, J. A. Merriman and O. S. Akbari. 2024. Identification of human skin microbiome odorants that manipulate mosquito landing behavior. Scientific Reports 14, 1631. https://doi.org/10.1038/s41598-023-50182-5
2. S. Nasci, C. W. Harris and C. K. Porter. 1983. Failure of an insect electrocuting device to reduce mosquito biting. Mosquito News 43(2):180-184.
3. B. Frick and D. W. Tallamy. 1996. Density and diversity of nontarget insects killed by suburban electric insect traps. Entomological News 107(2):77-82.
4. Sritabutra, M. Soonwera, S. Waltanachanobon and S. Poungjai. 2011. Evaluation of herbal essential oil as repellents against Aedes aegypti (L.) and Anopheles dirus Peyton & Harrison. Asian Pacific Journal of Tropical Biomedicine S124-S128.
5. Tassin de Montaigu, G. Glauser, S. Guinchard and D. Goulson. 2025. High prevalence of veterinary drugs in bird’s nests. Science of the Total Environment 964(10):178439.