How Pests Survive Different Types of Weather

Changes in the weather affect all beings in the general area of that particular climate. This includes humans, pets, wildlife, birds, and insects. It is obvious how we as humans handle a sudden storm or heat wave: we put on the appropriate clothing, stay indoors, or use a manmade tool to regulate our body temperatures, like a fan or a space heater. But insects do not have these luxuries, so they have to handle the changes in their own specialized ways. 

Cold

Insects are cold-blooded, which means their body temperature is heavily influenced by the weather and environment they are currently in. This also affects their activity level, as colder weather slows them down. And since the typical food sources of plants and other bugs are gone, insects need to seek shelter where it is warm and they can survive without food for a while until it heats up again. Certain insects can survive the winter just by flying to safety and even reproducing in some cases. Aphids survive because the females have wings that allow them to fly even in the cold, and they reproduce in winter as well. Female aphids are born pregnant with a lot of babies, so their population booms very quickly.

Some insects hibernate, like many mammals do in the winter. Adult insects are the ones who hibernate, and they will stay in holes, under rocks, or in their homes. A hibernating insect will stay in a dormant sleep state inside their home, and not emerge until it is warmer. Yellowjackets, wasps, and hornets all hibernate by staying inside their hives and huddling together for warmth. Ants also hibernate, but they cheat by finding someone else’s home to hide in for warmth, such as our homes. They will eat a lot first, more than usual, then go into shelter and hibernate until spring when they can go out and forage for food again. Cluster flies similarly like to invade homes for the cold weather, and they remain in clusters (hence the name) for protection and warmth. Regular flies will somewhat hibernate within their larva or pupa state. They will find something warm to hide under, like a pile of manure or a log, and stay there until it warms up and they hatch. Mosquitoes also hibernate, and can even stay in the embryo state for extra protection. Ladybugs and honey bees hibernate as well to stay warm and keep their colony alive. 

Snow

The most severe part of winter in most of the country is when it snows, and many insects do not have the protection for that. But the ones that do make it through the winter victorious and emerge in the spring to immediately begin becoming pests. Pests who stay in their home area will either hibernate, as discussed earlier, or go into diapause. This is the dormant state where no growing, developing, or moving is occurring. An insect in diapause does not do any sort of physical activity, so it is very similar to hibernating except for one key fact: hibernating involves actually sleeping for a while, and diapause is more about simply not moving. Honey bees hibernate, but they are also constantly active within hollow trees. The heat from the honey they have keeps their bodies warm combined with the close proximity to one another, so they don’t have to stop moving in their home if they do not want to.

Overwintering, the process of surviving the winter, can happen in any stage of the insect’s life. Each stage has its own special way of surviving the winter and snow. While not every insect in its early stages survives the snow and winter, these are the ways that these stages survive the winter when they can:

• Egg: Not many insects in the egg stage survive the winter since they are so small and vulnerable. One insect’s eggs that do survive is the praying mantis’s eggs, even though the mother dies due to the harsh conditions. The eggs stay dormant until spring when they hatch and begin eating other insects. Most insects don’t actively reproduce in the winter because of the low survival rate, so they don’t have to worry about this stage in the coldest months.
• Larva: There are a couple different ways that this stage overwinters. One is by getting under heavier natural covers, like leaves, that keep them warm in the snow. Another method is by burrowing underneath a sturdier cover, like mulch or under a log, to get the most reliable covering against the elements. But perhaps the most effective method, and one that adult insects can use as well, is by producing glycerol instead of water in their bodies. Glycerol acts as an anti freezing component that keeps the insect’s body temperature up and prevents it from freezing as the ground does. 
• Pupa: This stage best protects itself from the snow and cold by attaching itself to branches of a tree. This allows it to be off of the snowy ground and have a sort of protection from the majority of the snowfall. One notable insect that does this is the silkworm moth, which detaches itself from the tree in warmer weather and can fly now that it is fully developed.
• Nymph: This stage is for the insects that experience metamorphosis. It is when the wings are not completely developed yet, but they are very close to being a fully grown insect. Insects in this stage, like dragonflies and mayflies, keep themselves below ice and frost to protect their partial wings from freezing over. They also continue to feed and grow below the ice, which is very different from the other insects that abstain from all eating and developing in the winter. 

While snow and the winter can be potentially dangerous for many pests, it is actually beneficial for the insects that can survive. The snow provides insulation and a constant temperature for the cold-blooded pests, even if that temperature is very cold.  

Rain

While rain is not as severe as snow in density and temperature, it can still be detrimental to insects that choose to fly when the drops are pouring from the sky. Some insects can fly during a rainstorm, but the success rate all depends on the size of the insect and the size of the rain drops. For insects that cannot fly in the rain, they choose to hide in places that stay relatively dry in order to protect their wings and bodies. These places are typically underneath a cover of some kind, like under leaves, cracks, logs, rocks, and eaves. Some eggs may suffer as a result of the moisture and temperature drop. Grasshopper eggs actually rot if the soil is too moist and cold, so a rainstorm is not beneficial at all for them. Conversely, some insects, like the leaf-cutter, choose to mate when it rains due to the moisture and difference in atmospheric pressure. 

One insect that has been extensively studied due to its ability to fly in the rain is the mosquito. There are a couple of reasons why they are able to do what so many other insects cannot. One is their small size and weight, which allows them to survive the force of a raindrop, provided they are far enough above the ground. If the mosquito is flying low, a rain drop that lands on it will drive it into the ground and squish it. But if the mosquito is flying high, the mass will just push them down a little ways and not keep them from flying altogether. Another advantage that mosquitoes have is the natural hydrophobic hairs that cover their bodies. These minuscule hairs repel water and allow the mosquito to quickly dry off if they are hit by water. This is also how they are able to keep flying if a raindrop lands on them. But most insects do not have the abilities and body of the mosquito, so they don’t dare to join the mosquito in a rainy flight.

Wind

Wind is notorious for being a terrible time for insects to try flying. This is because the sheer force of the wind is many times larger than the insect’s body weight, so they aren’t strong enough to fly against the breeze. The wind blowing toward the insect drags it back and blows them way off course. In order for an insect to fly successfully, it has to fly with the wind at its back and utilize its body and wing movements in order to keep in the air. Small insects can clap their wings and keep some kind of movement constantly going, while others might wiggle and twist their wings to create some resistance. Insects that migrate actually use the wind to their advantage. They choose the path to their winter home by a finding a certain wind direction, and going towards the one of their choosing. They can then fly higher than normal and stay in the wind path as long as they need to in order to quickly get to their destination. These insects can also slightly control their body and wing movements in the strong wind so that they don’t plummet in the event of the wind suddenly dying down. Wind can be a bug’s worst enemy, but it can also be a wonderfully convenient way to speedily travel for the winter. 

Heat

Since bugs are cold-blooded and thereby influenced by the surrounding climate and weather, the heat of summer also affects them. Cold may slow them down, but heat makes insects far more active in every way. Some species, like desert insects, love the heat and cause their populations to boom during a heat wave. Common backyard insects, like aphids, thrips, and spider mites, enjoy the heat and seem to come out in droves in the summer. Spider mites especially love temperatures over 95 degrees, so a hot summer is paradise for these pests. One way to cut down on the number of pests in the yard during the summer is to use the hose or a watering can on certain plants that these insects love. While many homeowners use a drip system for watering their landscaping, it can help to water by hand so you can be sure that the hungry pests are washed away.

Other insects are certainly active during a heat wave, but for the opposite reasons. Wasps and Yellowjackets get more aggressive during the hot summers because they are agitated. They need moisture to thrive, and dry heat zaps that from them very easily. Excessive, prolonged heat also kills mosquitos, who love moisture and need some form of standing water to survive and lay their eggs near. When water dries up, so do mosquitoes. So while a hot summer may be miserable for us, at least we can avoid it in the comfort of our homes until the heat becomes less intense, unlike many unhappy insects. 

Pest Control 

Whatever the weather, pest control is a great option if you are concerned about any potential infestations or current pest problems. It is worth looking into, especially in the changing of the seasons, so that you can be sure that your home will remain pest-free when the weather fluctuates and the seasons shift.

Citations

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Corney, C. (n.d.). How do butterflies manage to fly in the wind? Science Focus. Available at https://www.sciencefocus.com/nature/how-do-butterflies-manage-to-fly-in-the-wind/ (Accessed on March 9, 2022). 

Fang, J. (2010, February 4). Moths catch the wind to speed migration. Nature. Available at https://www.nature.com/articles/news.2010.54 (Accessed on March 9, 2022).

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Olson, E. (2012, June 4). How mosquitoes survive collisions with raindrops. Scientific American. Available at https://blogs.scientificamerican.com/observations/how-the-mosquito-survives-a-raindrop-collision/ (Accessed on March 9, 2022). 

Miorelli, N. (2015, April 20). What do bugs do when it rains? Ask an Entomologist. Available at https://askentomologists.com/2015/04/20/what-do-bugs-do-when-it-rains/ (Accessed on March 9, 2022). 

Roduner, M. (2019, February 14). Cool, wet weather affects insect populations. South Dakota State University Extension. Available at https://extension.sdstate.edu/cool-wet-weather-affects-insect-populations (Accessed on March 9, 2022). 

Schuh, M. (2021, June 10). How a heatwave affects garden pests. University of Minnesota Extension. Available at https://extension.umn.edu/yard-and-garden-news/how-heatwave-affects-garden-pests (Accessed on March 9, 2022). 

What do insects do in winter? (2019, December 20). Rescue. Retrieved on March 9, 2022, from https://www.rescue.com/latest-buzz/seasonal-bug-bulletin/what-do-insects-do-in-winter/ 

Where do insects go in the winter? (n.d.). Smithsonian. Retrieved on March 9, 2022, from https://www.si.edu/spotlight/buginfo/winter#:~:text=Insects%20that%20are%20inactive%20during,dormant%20condition%20is%20termed%20diapause