It has been way too long since I posted here. For several months I have been meaning to resurrect this blog, but it seems very easy to post a picture and short comment on FaceBook and then go surf it for a while, adding random comments and “likes”.
Well, today’s subject, Japanese beetles, is too lengthy and complex for a Facebook post. This is a shot of a large group of them clustered on a tall evening primrose.
Like much of the Midwest, we are “enjoying” a population explosion that was probably not predictable back in 1906 when the first Japanese beetle was noticed in New Jersey. It has taken a while, but they have grown into a monstrous problem. Aside from the fact that the pest was imported without also importing its natural predators, the climate back in 1906 was a big help in controlling the population.
The life cycle of this little insect is pretty simple. It eats, voraciously. It breeds, orgiastically. In the late summer it drops to the ground and lays its eggs. The larvae live through the winter underground, subsisting off of the roots of the grasses the eggs were laid in. In the late spring, they emerge to start the cycle over again.
What has made them so devastating in these latter years is that our winters have gotten milder, so the larvae do not get killed off by cold the way they used to be. If the ground doesn’t freeze, the brood survives intact and the population gets larger and larger.
This is what our vineyard looks like right now.
All those golden brown leaves are skeletonized grape leaves.
If you don’t have enough leaf surface area, your grapes won’t ripen. Now if you look at the above picture, you will notice that there IS hope, as the grape vines are heroically putting on new growth at the leaf axils of all those devastated leaves. In some places there are lots of new vines sprouting as well. The grapes are so confused by it all that they are even making new blossoms.
This is what they have to contend with, though. There are thousands and thousands of beetles. We go out and hold jars with water and lamp oil in them under the groups of beetles, tap the leaves and they fall into the jars (mostly, a lot of them fall outside the jar) and die. We do this several times a day. We have killed gallons and gallons of these beasts.
In the fall we will invest in milky spore, a soil bacteria that infects and kills the larvae during the winter. If only all our neighbors would do the same.
It is so frustrating. This is the face of globalization: pests like the Japanese beetle or the Emerald Ash Borer get imported along with the products we desire. (There are numerous other examples, too.) It is exacerbated by global climate change, when a pest that is imported can expand exponentially because the usual climatic conditions that help control it are absent.
If we don’t get a great grape crop, it means we won’t have as much wine to drink next year, a situation that is not life threatening. But that does not mean that widespread introduction of new species and global warming is not something to be concerned about.