The Four-Lined Plant Bugs of the Apocalypse
It’s odd how after they mentioned this bug, I started seeing it everywhere. This either says something about my limited powers of observation, or suddenly my four-lined plant bugs stopped using their invisibility cloaks.
Four-lined plant bugs have piercing mouth parts. They suck the chlorophyll out of the leaf cells, which sounds rather sinister. After that the cells turn brown or black and may fall from the leaf, leaving little holes. If there is enough damage the leaves may shrivel up.
There is one good thing about four-lined plant bugs: they don’t stick around for very long. They hatch in May or June and mature over about six weeks. Then they feed for another month or so, mate, and die, leaving their eggs to overwinter. They have only one generation per year.
Healthy plants should recover from the vampire-like attentions of the four-lined plant bug. The damage is cosmetic, though it can look darn ugly.
In my garden it looks like these bugs have matured, so they should be around for another month or less. When they are gone I may cut back the damaged plants – primarily Culver’s Root (Veronicastrum virginicum) and Anise Hyssop (Agastache foeniculum). It doesn’t make sense to me to cut the plants back while the bugs a still feeding.
My hope is that everything will recover by August 1, when our garden will be part of the Wild Ones garden tour. If not, I’ll survive.
I considered using an organic insecticidal soap, but decided against it. My understanding is the soap can kill non-target insects, including beneficial predators. My garden has been remarkably free of insect pests for some years, which I attribute to a diverse and balanced insect population. In order to maintain that balance, I will tolerate some cosmetic damage, even some delayed or lost flowering.
Do you ever use insecticidal soaps? If so, at what point do you think it is warranted?