Whether you have encountered them in your garden, on a walk, or even as little intruders in your home, you might have wondered before: do ladybugs bite or sting?
Ladybugs bite their prey. They feed on other insects and as such have mandibles required for chewing. Their mouth is made for biting through the soft bodies of insects like aphids, though, so they are only rarely able to break human skin.
The person that has been bitten will only feel a slight sting and notice a small mark on their skin. Ladybugs bite when they feel threatened or in circumstances when they cannot find any food or water.
Does the Species Make a Difference?
Worldwide there exist more than 5000 different ladybug species with a great variety in their color as well as patterns and numbers of their spots. 24 of these ladybug species are known to appear in the United States.
The small, red, native species that most people immediately think of when they hear ladybug or lady beetle (or rather ladybird, if they are British), Harmonia axyridis is not very much into biting in general.
Since the 1910s, ladybugs have been imported mainly from Asia because of recommendations from scientists, so that they could be introduced into the native insect population of European and American countries because ladybugs are known to eat pests that would otherwise destroy crops.
This made these beetles beloved in the field of agriculture. Some of these species, though, turned out to be very invasive and be a threat to the native species of ladybugs.
One of these invasive species is also indeed a species of ladybug that is more likely to bite humans. The so-called Asian harlequin ladybug belongs to the same kingdom, phylom, class, and order as the native ladybug, so they can both be classified as different forms of Harmonia axyridis.
Their main difference is that the common native ladybug belongs to the Coccinellidae family and the harlequin is a member of the Scarabaeidae family – yes, just like the big Egyptian scarab beetles.
The harlequin ladybug is not only a bit bigger but also more aggressive and tenacious when it comes to finding nutrition than other species.
Harlequin ladybugs are also more likely to congregate in swarms. You can recognize this species by its color that goes more into the range of orange than red.
Often, Harlequin Ladybugs also leave behind an unpleasant odor and discolored stains. This is how you can recognize if they have been inside your home.
In 2014, a group of scientists conducted a study to find out if more brightly colored ladybugs are more aggressive or toxic, since in the animal kingdom bright colors often function as a warning of poisonous or venomous animals. Most ladybugs have indeed a small amount of toxins in their body.
The toxic chemicals ladybugs produce are often connected to the abundance of carotenoid that leads to the red and orange coloring of their shell, like in the harlequin ladybug mentioned above, or in the seven-spot ladybug, Coccinella septempunctata.
The researchers found out that the least toxic of the species are brown-colored ladybugs, which are usually larch ladybugs. This goes well with the idea that more muted colors indicate less danger.
Orange ladybugs like the harlequin ladybugs are the most toxic species and black ladybugs, like the pine ladybug, a black beetle with small red spots, come at a close second.
While red ladybugs can be predatory and are able to defend themselves, they are not as toxic as their orange-tinted cousins.
Bug Bites in Numbers
Entomologist J. Kovach performed a study on a sample of 641 ladybugs in 2002. To test their willingness to bite even unprovoked, the scholar placed the bugs in 11 plastic containers and, after washing, sterilizing, and air-drying his hands to get rid of any substances that could attract or repulse the insects, he offered them his hands for their delectation.
Whenever a bug bit him, it was removed from the container and counted.
It turned out that 26% of those 641 bit him when given the chance. As the study found, the bugs were more likely to bite into areas of skin that are not covered by hair, like the fingers of the insides of the wrists.
Once the first bug broke the skin, other bugs would be attracted to the same spot. In general, female ladybugs were a little bit more likely to bite than male ladybugs.
What Happens If You Get Bitten By a Ladybug?
Ladybug bites are mostly not very painful. Sometimes, though, they leave a small bump that can hurt for a few days.
Be aware that not every sting you feel when touching a ladybug has to be a bite – ladybugs can also pinch you with their legs!
This too can also leave a mark, and for people that are allergic to ladybugs, it does not make any difference whether they have been bitten or pinched.
According to David Goetz, M.D., Ph.D., ladybugs (together with cockroaches, cats, and house dust mites) are among the most common allergens to present as isolated single positive skin tests and he argues that ladybug should be a standard skin test allergen for allergy patients.
Dangers in Ladybug Bites
Unlike some other insects, like for example mosquitoes, ladybirds are not specialized in feeding on animals, so their saliva does not carry any venoms or toxins.
The toxins they carry are inside their body and blood, so you could argue that it is more dangerous to bite into a ladybug than getting bitten by one – do not worry, you would have to consume quite a large quantity of ladybugs to be in any danger!
Keep an eye on your pets, though, some dogs react badly to eating ladybugs.
Luckily, ladybugs do neither carry any parasites nor diseases that are dangerous to human beings.
However, there is a small chance that a bite might become infected. If you wash it out with soap or water immediately, though, this risk is nothing to worry about.
As mentioned above, there is also the possibility of an allergic reaction. Some species of ladybugs have proteins in their bodies that can cause swelling of the lips and airways in those people who are allergic to it.
If you notice unusual swelling around the area of the bite, rashes, have problems breathing, or notice any other symptoms that worry you, seek medical attention.
Better yet, take a preventive allergy test to find out if you have to be wary of the company of ladybugs.
Is There a Time of the Year When the Risk of Ladybug Bites Is Especially High?
During the time of the year in which their diapause, which is the term for hibernation, takes place, ladybugs tend to flock together in swarms to conserve resources and have a large selection of female and male bugs in one place so that they are ready for mating season.
Ladybugs do not like the cold, and in their search for a warm place to hibernate, they might even enter homes.
Therefore, in fall and winter, you have a bigger chance of encountering a large group of ladybugs than in the summer months, which increases the chances of being bitten.
To prevent ladybugs from entering your home, keep your windows and other entry points properly sealed for example by caulking them. Also, look for external cracks or openings that ladybugs could potentially crawl through. Install screens over roof vents and check current window screens for damage.
There are also plants that are known to deter ladybugs, like chrysanthemums and lavender. You can plant lavender around your home as a sort of protective barrier, or keep some stalks in a vase on your bedside table.
How to Avoid Getting Bitten?
Ladybugs are often considered to be symbols of good luck and as such, they do not elicit the typical shocked or grossed-out reaction that other insects tend to evoke.
Especially small children, who have not yet internalized to automatically categorize anything that creeps and crawls as ‘disgusting’ like taking those colorful and fascinating little beetles up in their hands.
Mostly, nothing bad will happen, so you do not need to worry too much for the safety of your little natural explorer; unless, of course, they have taken an allergy test, and are known to be allergic.
In any case, it is generally very easy to notice if a ladybug is not enjoying being handled and might get aggressive soon.
When ladybugs feel threatened, they do what is called joint-bleeding – they secrete a small amount of blood from their joints that contains the toxins mentioned above.
The reddish-brown fluid with the unpleasant smell is often mistaken for ladybug pee, but that is not the case. The appearance of such a stain on your skin is a sign that it is time to put the ladybug down and leave it alone.
If you want to learn more about various insects, then checkout our site categories, we have a bunch of articles there that are totally worth reading:
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