As I walked the rows of my garden, I noticed that my turnip leaves were looking ragged. Something has been chewing away on the turnip greens, which is odd. I’ve never had this problem in the past. On further investigation, I discovered many insects hanging out in my little turnip patch. Here I interrogate three turnip eating suspects to determine the guilty pest.
Turnip Eating Suspect #1: Grasshopper Nymph
Grasshoppers will definitely eat leaves, but this was one small insect so I’m thinking that all the damage wasn’t due to this one tiny grasshopper.
Turnip Eating Suspect #2: Harlequin Bug
This pretty bug isn’t a gardener’s friend. Harlequin bugs are sap suckers, so I can’t blame it for all the eaten leaves. However, these bugs can cause plants to wilt and die due to sap sucking. Cabbage is one of their favorite plants along with other Brassicas, including turnips. I found two of these in my turnips, which isn’t a good sign and may cause problems in the future, but they are not the ones eating the turnip leaves.
Turnip Eating Suspect #3: Yellowmargined Leaf Beetle
These little beetles look harmless. However, there are a ton of them among the turnip leaves. This is a non-native species from South America that has invaded the southeast of the United States. They like to eat the leaves of Brassicas and turnips are their favorite crop! It appears I have found the guilty suspect.
The next question is what to do about these yellowmargined leaf beetles. This website from the University of Florida has some helpful information. For conventional growers, use of insecticides is effective. For the organic grower, like me, the prognosis isn’t as good. It is difficult to control their populations without synthetic pesticides. Some good news is that they are only active during cool weather and become inactive once the temperature is consistently above 80 F. We’ve had unusually cool weather the last week, but it is warming up, so hopefully they won’t do too much more damage.
The spined soldier bug is a predator of the yellowmargined leaf beetles. Unfortunately I did not see any among my turnips, yet. Maybe reinforcements are on their way! In the meantime, I will use my tedious pest management technique: a jar of soapy water, my hands and the time to pick off the little bugs. I know it will be impossible to get every individual, but hopefully if I can put a dent in their population then my turnips can grow and survive.