Aphids are sucking insects. They can cover the leaves of a plant alarmingly and are indeed a headache for houseplants. But we are growing outside, where all the resources of a robust ecosystem will come into play. So there is no need for Aphid Anxiety.
Most native gardeners find aphids on their honeysuckle plants and on their milkweed. Unless the plant is very young, they will not kill it. Even better, they will attract predators who will feed on them. Ladybugs, lacewing larvae, and several beneficial wasps feed on aphids. It may test your patience and your self-calming abilities, because the predators don’t usually come around until the aphids are abundant. Be on the lookout for ladybug LARVA or EGGS, not necessarily the adult Lady Bugs.
The Lady Bug larva grows and sheds it’s exoskeleton several times until it pupates. If you look carefully you may see the discarded exoskeletons on a busy leaf. The larva can consume several dozen aphids per day. The pupa looks like an odd-shaped, squished up Lady Bug, and hangs from the bottom of the leaf. After about a week, the pupa transforms into the adult Lady Bug.
Please Don’t Spray the Aphids, or Order Lady Bugs by Mail
Applying pesticide to control aphids will harm the beneficial insects. Ordering commercial Lady Bug or lacewings may have unintended ecological consequences. You may be unwittingly increasing the population of the Asian Lady Beetle, or you may be encouraging the wild collection of the ever-diminishing populations of native Lady Bugs.
Populations of the native Lady Bug have been declining since the 1980’s, while the population of the Asian Lady Beetle has been soaring. Three species of Lady Bugs in particular used to be quite common and are now very rare: the two-spot, the nine-spot, and the transverse (Adalia bipunctata, Coccinella novemnotata, Coccinella transversoguttata). Over half of the ladybugs found in North America are foreign species, with the Multicolored Asian Ladybug being the dominant species.
You may have seen lady beetles in the house during the winter. These are not the native Lady Bug; they are the Asian Lady Beetle. Native Lady Bug species spend the winter outdoors, in leaf litter, under tree bark, or in natural crevices. One species migrates and hibernates in the mountains of the western US. It is the migrating Lady Bug that is sometimes collected from their winter location in the mountains, using back-pack vacuums.
Our Aphid Advice
Our aphid advice? If your plants are mature, ignore the aphids. If your young plant appears to be suffering from aphids, use a gloved hand to smash them and wipe them off.
It’s Usually Only Temporary, Anyway
Aphids are attracted to fresh, young growth. They are abundant in spring when plants are flush. If you have a population of them and can manage to ignore them, they will dissipate in a few weeks. Then you can return to enjoying your garden stress-free. In the meantime, enjoy looking closely for lady bug eggs and larvae. Watch nature in action!