From there, it quickly expanded to the Midwest over the next 5 to 7 years
The eyes staring back at you in this photo come from an Asian lady beetle. This species of ladybug was introduced artificially to the United States to control aphids and scale. Insects is now found throughout North America and Europe, which is outside of its native lands of eastern Asia. The first introduction into the United States was as early as 1916. Until 1988 it was only found in agricultural settings, but in that year it established a wild population near New Orleans Louisiana. From there, it quickly expanded to the Midwest over the next 5 to 7 years.
The Asian lady beetle goes by many names: Harlequin lady beetle, multicolored Asian lady beetle, Halloween beetle, and its scientific name Harmonia axyridis. The pronotum of the Asian lady beetle is distinct in that there will be a black M or W. The pronotum is the portion of the thorax that is immediately behind the head. On ladybugs, this often appears like a head with eyes. It is used to distinguish many species of ladybugs from one another.
In the supporting photo above, you can see the larva stage of the Asian lady beetle. At this stage, they are black and orange with spikes all over their body. The larva emerges from the egg of a ladybug at around the 2 to 10 day mark. At this stage, they are already beneficial for agriculture, because they will eat aphids and other soft bodied plant pests. One lady beetle larva can eat up to 400 aphids in three weeks before it pupates. From the 7 to 15 day mark, they will stay entirely still on a leaf as it transforms from a pupa into an adult.
The Asian lady beetle like other ladybugs has hardened elytra. What is an elytron you may ask? This is a pair of wings on beetles that is hardened to protect the hind wings. The hind wings are kept underneath the elytra. Asian lady beetles can be distinguished from other species by the pattern on the elytra. They have 0 to 22 black spots on a background of orange or red.
The hind wings are kept underneath the elytra
Did you know?
- This species is widely, considered the world’s most invasive insect in part due to its tendency to over winter indoors.
- They were congregate and significant numbers inside walls. They secrete a pheromone in the winter that signals them to join together to overwinter.
- Asian lady beetles will release a hemolymph from their legs when startled, which has a foul odor and a bitter taste.
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