Ladybugs are often touted as a safe solution to aphid problems in the garden because their use doesn’t involve harmful pesticides. The little spotted beetles are popular all over the world, and in ancient times they were thought to be indicators of good fortune and a bountiful harvest. However commercially available ladybugs are not native to the US, and pose a threat to the natural ecosystem that many folks are unaware of.
What’s wrong with importing ladybugs?
Initially–these commercial lady beetles are wild caught, harvested during hibernation, and they may not be ready to feed when you introduce them in your garden. Or they may not feed on the intended target pest. Also, if your garden is not hospitable to the ladybugs, they may simply fly away in search of a better home.
The non-native lady beetles are a very predatory species, which displaces the native species, literally eating the native lady beetle populations out of house and home. The Asian variety has become a pest which overwinter in large number inside homes.
The 2-spot lady bird and the Asian lady beetle are both known to carry parasites and diseases that could be introduced to local populations that might not otherwise have been exposed. Research indicates that 3-15% of the harvested ladybird beetles carry an internal parasite called Dinocampus coccinellae. At the same time many of them are also infected with Microsporidia–a disease that shortens the ladybird’s lifespan and reduces the number of eggs laid by the females.
How can you attract native ladybugs?
Rather than importing these aggressive invasive species, gardeners can employ some alternative methods to attract native ladybugs naturally.
Planting flowers among your crops will attract a variety of beneficial insects, from bees that will aid in pollination, to predatory wasps that will eat cabbage worms, and even the beloved ladybugs. Since lady beetles supplement their insect diet with pollen and nectar from flower, plants that are heavy pollen-producers will lure them to your garden. Composite flowers, or flower-clusters, provide a place for the ladybugs to nestle when they are not hunting.
Some great companion plants that attract ladybugs are:
- Sunflowers and other aster-family flowers, such as marigolds, coneflowers, calendula, and cosmos.
- Herbs like cilantro, dill, a chamomile.
- Composite flowers including yarrow, Queen Anne’s Lace, and sweet alyssum.
Above all, do not use pesticides in your garden or yard if you want to employ ladybugs! Even organic pesticides will impact their populations, leaving you ladybug-less and with aphids aplenty.
Are ladybugs worth the trouble?
Absolutely! They are definitely one type of insect you want in your garden; but buying lady beetles is not the best way to get them there, what’s more–it’s ecologically irresponsible. Instead, creating an inviting habitat is a solution that will not only attract your ladybugs, but other beneficial insects as well–and that benefits your garden along with your local ecosystem.
Some thoughts on buying ladybugs for the garden – Berkeley Garden Coach
Aphid control with ladybugs – the Beneficial Insect Co.