When it comes to the topic of what eats oleander aphids, one particular creature that stands out is the multicolored Asian lady beetle, also known as MALB (Harmonia axyridis). These insects, both in their adult and larval stages, have been observed to consume early instar monarch caterpillars. However, a study conducted in 2005 revealed that the feeding preference of MALB is density-dependent, meaning it is influenced by the availability and abundance of food sources.
In this study, researchers found that when given a choice, MALB exhibited a strong preference for consuming oleander aphids over monarch caterpillars. Oleander aphids are small insects that infest plants, particularly oleander bushes, and feed on their sap. The presence of these aphids can be detrimental to the health and aesthetics of the plants they infest.
The density-dependent preference of MALB for oleander aphids implies that as the population of aphids increases, the lady beetles become more inclined to feed on them. This is likely due to the fact that oleander aphids are a more abundant and easily accessible food source for the lady beetles. In contrast, monarch caterpillars may be less readily available or present in lower numbers, causing the lady beetles to prioritize the aphids as their primary food source.
It is important to note that while MALB may consume oleander aphids, they are not necessarily the sole predator of these pests. There are other natural enemies of oleander aphids, such as lacewings, ladybugs, and parasitic wasps, which also play a role in keeping their population in check.
As a gardening and landscaping expert, I have encountered instances where oleander aphids have infested plants in various settings. In such cases, I have observed lady beetles, including the multicolored Asian lady beetle, actively feeding on these aphids. Their presence and feeding behavior serve as a natural form of pest control, helping to reduce the aphid population and protect the health of the plants.
While the multicolored Asian lady beetle (MALB) has been observed to consume early instar monarch caterpillars, a density-dependent preference for oleander aphids has been documented. When given a choice, MALB tends to prioritize the consumption of oleander aphids due to their abundance and accessibility. However, it is important to recognize that MALB is not the only predator of oleander aphids, and other natural enemies also contribute to controlling their population.
