Nature Talks: Ladybeetle, Ladybeetle fly away home
The multicolored Asian ladybeetle looks like our native ladybeetles but it does not belong here. JEANNIE CARL/SPECIAL TO THE TIMES NEWS
Before working at the center I never gave invasive species a second thought but after answering questions about various species that aren’t native I realized what a huge problem invasive species are in the environment.
The multicolored Asian ladybeetle looks like our native ladybeetles but it does not belong here. Asian ladybeetles are also known as “Harlequin ladybirds” due to variations in their coloring. Today, these beetles have become a statewide pest. One may ask, “What could be so pesky about a ladybeetle?
Well, read on.
This ladybeetle species was introduced into the U.S. from Asia in the late 1900s by the U.S. Department of Agriculture to control agricultural pests. The USDA released the ladybeetles in Georgia, South Carolina, Louisiana, Mississippi, California, Washington, Pennsylvania, Connecticut and Maryland, and is found throughout most of the U.S.
Our native ladybeetles (nine-spotted, convergent, and parenthesis) are all gentle species that have been displaced by the Asian ladybeetle. The most common native species in North America is the convergent but its numbers have declined because of the invasive Asian beetle.
Twenty years ago, across North America, one could find thousands of ladybeetles. Now it´s a rare treat to spot (pardon the pun) natives. Although native ladybeetles are gentle and beneficial to one’s garden, the Asian ladybeetle can actually become a pest. Today, there are very few native ladybeetles; so much so, that there´s an actual website dedicated to “lost” ladybeetles!
The “Lost Ladybug Project” petitions help from the public to photograph native ladybeetles found throughout the country, such as the nine-spotted, parenthesis, and European seven-spotted ladybeetle.
At a quick glance, it can be hard to tell the difference between the Asian ladybeetle and beneficial natives. This is because the color of the Asian species can vary from light tan or orange to bright red with no spots or up to twenty-two spots. But if you look closely, you will see the Asian ladybeetle has a white marking behind its head resembling an “M.” The Asian species is also a bit larger than most native ladybeetles.
Several North American ladybeetle species have declined in numbers resulting in the native nine-spotted ladybeetle becoming an endangered species. First documented in the late ’80s, reasons for the decline include nonnative ladybeetles introducing diseases, stress caused by competing for the same food source and having the larvae eaten by the stronger and hardier Asian species.
Homeowners have reported sinus problems due to large infestations of these pests. Some people can have allergic reactions to the beetles including eye problems, such as conjunctivitis (or “pink eye”), asthma attacks, or hives. Reactions can be triggered by touching the lady beetles then touching your eyes, or just by being around a large or lengthy infestation. They may look cute but they can and will bite!
The beetle’s defense, when disturbed, is to emit a yellow, foul-smelling chemical which can stain walls and other surfaces. So what to do if you have an infestation? Sealing any cracks around doors and windows may deter them but if they do get inside the easiest method is to vacuum them up and destroy them. Sweeping them up with a dust broom is most likely going to result in the release of this chemical.
Asian ladybeetles can be aggressive and bite if they land on the skin. Although they do help rid gardens of plant pests, they are becoming a problem in vineyards, where they are being collected along with the grapes resulting in an “off” taste in the wine.
The next time I’m out hiking with my camera, I will be “hunting” for nine-spotted, convergent, and parenthesis ladybeetles.
Jeannie Carl is a naturalist at the Carbon County Environmental Center, located at 151 E. White Bear Drive, Summit Hill. Call 570-645-8597 for information or visit www.carboneec.org.