Subject: Another reason to hate Asian Lady Beetles
Location: Central MN
August 14, 2012 8:21 am
Hello bug nuts!
I found this (presumed) native lady beetle larva in our garden last night, and then another on a different milkweed. But the second was being consumed by a much larger lady beetle larva, (presumably) of the Asian Lady Beetle variety.
Our milkweeds are being bombarded by another exotic species, the Oleander Aphid, so this ladybug on ladybug violence just seems unnecessary.
Thanks again for your exceptional site! I visit it everyday.
Signature: Don J. Dinndorf
Thank you for submitting this heartbreaking documentation. We doubt there is little that can be done regarding the invasion of the exotic Asian Multicolored Lady Beetles as they have already become established coast to coast in North America. It has long been known that native Lady Beetles are becoming scarcer, but the reasons are not fully understood. The Agricultural Landscape Ecology Lab at Ohio State University is conducting a study. We don’t know if this cannibalism is documented elsewhere, but we will try to find out additional information. We did locate this article entitled Predation and cannibalism of lady beetle eggs by adult lady beetles by Ted E. Cottrell. We have long thought that the Oleander Aphids are seriously compromising our native Indian Milkweed here in Mount Washington, Los Angeles, CA. When the Oleander Aphids are plentiful, the milkweed gets a type of mildew. The problem is further exacerbated because the Argentine Ants protect and disperse the Aphids because they want the honeydew. Plants with dense Aphid populations are not producing seeds. We will try to figure out what species your native Lady Beetle Larva belongs to. Here is information from the USDA fact sheet on the Multicolored Asian Lady Beetle: “Multicolored Asian lady beetles have become a problem in some regions of the United States. It is probable that their introduction into new habitats in the United States freed these lady beetles from some natural population checks and balances that occur within their native Asian range. It is likely that these natural controls will catch up to the lady beetles in time and curtail their booming population. Additionally, a period of time may be required for checks and balances of our native lady beetles to adapt to this newcomer.” The Multicolored Asian Lady Beetle is still considered to be a beneficial insect and it is expected that its population will eventually stabilize and it is unknown if its presence is responsible for the decline of native species.