Identification of Lady Bugs – Asian Vs. Native Lady Beetle
Asians have been known to use lady bugs for centuries, but they were not native to North America until European settlers brought them here. They are now found all over the world including Australia, Asia, Africa and South America. However, the most common species in North America is the red imported from China (Amanita phalloides).
Red imported ladybug is commonly called “redback” because it is so beautiful.
Ladybugs in general are very small insects, less than 1/4 inch long with wingspans of only a few millimeters. Most ladybugs are dark brown or black, although some may be lighter colored like yellow or white. Some species have bright colors such as orange and greenish purple, while others have duller colors such as grayish blue.
The coloration varies among different species and even within the same species within the same genus.
The female ladybug lays her eggs inside a host plant, usually a citrus tree. After hatching, the young larvae feed on the leaves and stems of their hosts for several weeks before emerging from the plant to pupate into adults. Adults emerge in late summer or early fall and mate with one another, laying hundreds of eggs in batches.
These eggs hatch after two months into tiny maggots which develop rapidly and begin feeding within six months. There are four or five life cycles in one year.
Asians are usually found on the leaves, stems and roots of their host plants. Native ladybugs are usually found on the undersides of leaves where they feed on aphids and other insects. Asians also consume large quantities of pollen and nectar when available.
Asians usually release a foul smelling yellowish fluid when they feel threatened, but not always. Native ladybugs usually do not have this capability.
Asians tend to fly away when approached, but only for a short distance. Native ladybugs will either fly away or crawl away on their own, and rarely attack when approached. Of course, these are general rules that may not apply to all individuals within each group.
Asians tend to gather in large groups, sometimes hundreds or even thousands of individuals. Native ladybugs are usually found alone or in small groups.
Asians tend to hibernate in large groups during winter. Native ladybugs hibernate alone or in small groups. A ladybug that has come indoors is probably a native species if it is found hibernating alone.
Asians have a yellowish or orange line in the middle of their backs while the back of the ladybug is a solid color. Native ladybugs have no markings on their backs.
Asians are usually larger than native ladybugs. Native ladybugs are usually smaller than Asian ladybugs.
Asians are usually slow movers while native ladybugs tend to be very quick and active.
Asians have a rounder body shape while native ladybugs tend to be more slender in shape.
Asians usually have dark wings with prominent veins while native ladybugs have lighter colored wings with faint or no veins.
Asians are attracted to light colors such as yellow and white, while native ladybugs are not attracted to these shades.
Asians can sometimes be found on the ground but are usually only seen on plants. Native ladybugs are always found on the ground.
One of the most reliable ways to tell if you have an Asian or a native is by looking at the spots where eggs were laid. Native ladybugs lay their eggs in groups, usually all in a small area. The eggs are immobile and attached to the surface where they were laid.
Asians lay their eggs individually in random locations. The eggs are sticky and can be easily moved around with your finger.
Asians tend to come indoors more often than native species.
If you believe you have found an Asian ladybug, there are many things you can do. On the positive side, asians eat a lot of other insects and can be very beneficial if allowed to stay. On the negative side, asians will eat the fruit off your trees and flowers off your plants.
Native ladybugs will not do this.
If you must get rid of your asian ladybugs, you might try introducing native predatory insects to get rid of the asians. You’ll have to experiment with what will work in your area. Another option is to introduce a second batch of asians that will mate with the first group, producing infertile eggs.
You can also just wait a few weeks for them to leave on their own. Most asians are only active for a few weeks each year. They over-wintered in your home and started to breed.
After a few weeks they will be ready to mate again and the males will venture out in search of mates. The females will soon follow, leaving your home to look for other places to hibernate for the winter.
There are many things you can do to prevent this from happening again. Check your windows and doors to make sure they are completely sealed. Check the screens on your vents and fans to make sure they are secure.
Check around your roofline and make sure there are no holes or gaps where ladybugs can enter your home.
If you have a bird feeder, make sure it is kept clean as dirty feeders will attract multiple insects including insects that ladybugs like to eat.
Try to avoid using pesticides and other chemicals around your home. Many of these are harmful to ladybugs and the native species will be no match for the asian invaders that have built up a tolerance for these chemicals.
There is no way to get rid of all of the asians in the area, but their numbers can be kept low. Getting rid of a few each year keeps their numbers low enough that they cannot take over the native species.
After a few years you should have a large population of native ladybugs that keep the asian numbers low. There will always be the odd asian hanging around, but they will no longer be able to take over.
If you would like to help out even more, you can start looking for the native egg clutches during the spring and summer and moving them to a safe location. This takes a lot of time and effort but can be very beneficial to the local ecosystem.
You can also try to spread the word and get others involved in helping native species. You might also try to come up with other solutions that can be shared on the internet.
Just remember, each area is different and will require different efforts to control the asians. Some places may be so overrun that nothing can be done to save the natives. Each person can only do so much.
But together we can Save our Native Ladybugs!
You decide to take a more active approach in helping save your local ladybugs.
Sources & references used in this article:
Identification of (−)-β-caryophyllene as a gender-specific terpene produced by the multicolored Asian lady beetle by AE Brown, EW Riddick, JR Aldrich… – Journal of chemical …, 2006 – Springer
Invasions by Harmonia axyridis (Pallas)(Coleoptera: Coccinellidae) in the western hemisphere: implications for South America by RL Koch, RC Venette, WD Hutchison – Neotropical Entomology, 2006 – SciELO Brasil
Citizen scientist rediscovers rare nine-spotted lady beetle, Coccinella novemnotata, in eastern North America by JE Losey, JE Perlman, ER Hoebeke – Journal of Insect Conservation, 2007 – Springer