Hops: predatory bugs

Asked July 6, 2017, 1:49 PM EDT

Our hops, encircling an arbor, are being laced. At first we thought it was aphids since there was evidence, so we bought lady bugs. Now they are being laced with bigger holes than an aphid would make. I have found these critters on various leaves--just lately in evidence as I check often--some alive, some only desiccated skin, as if they were shedding. Could these be a Japanese beetle? I am enclosing photos.

Lane County Oregon

4 Responses

Thank you for attaching the images to accompany your inquiry. The news is good: (1) The images clearly show that lady beetles have been working hard on your behalf. And (2) the holes occurred quite some time ago; thus the pesky fellows that created them are likely long gone.

In addition to that, be assured that, even if those pests were still active, the amount of damage is not significant to the plant.

Lady beetles dine on aphids and other small insects, including young caterpillars. They don’t make holes in leaves.

“HopsBug 1” is a lady beetle youngster – rather strange looking isn’t it, rather like a colorful mini-alligator? “HopsBug 2” and “HopsBug 3” are lady beetle pupae; pupae are the intermediate life stage between the youngsters and the adults. Within a relatively short time you’ll notice that each pupal case has split down the top surface. If you happened to be there at the time, you would also see the adult beetle walk away, on the search for prey.

See “Growing Hops in the Home Garden” (https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9115.pdf).

Thank you so much for the prompt and good info! So they are lady beetles, or 'bugs' as I've always called them, that is wonderful to hear since they are all over the leaves. As for the holes, you mentioned that they are old, but more appear every day. A month ago there were no holes, now they are wide-spread and getting worse. This particular arbor, where the hops are, will be the setting for a wedding in a couple of months and I was hoping to have lovely hops. Also, this kind of leaf-lacing has been going on for several years. Could there be something in the ground? thank you, Patty

The holes in the images have dry edges. When chewing damage is new, the edges of the holes are fresh and juicy. (You can imitate such damage if you make a small tear in a green leaf.) There’s a good chance that the shredding shown in “HopBugs 1” were caused by hail some weeks ago; such damage can appear to get worse as the leaf expands.

Some insects feed from the underside, so are seldom seen. Similarly, some chewing pests come out only at night. For the latter, the gardener must go outdoors at night, flashlight in hand, to catch the culprits in the act. Among the chewers which are listed as potential pests of hops are several kinds of caterpillars; earwigs; root weevils; and cucumber beetle. Rather than using a spray, I suggest you flick them into soapy water when you see them. Sprays are useful only when you know what the target is.

Several days before the wedding, remove the most objectionable leaves. But you can trust me I say that you will be the only person to see these small holes whereas your guests will be interested in the wedding and refreshments!

Thanks again! I love your comments about the guests not being so interested in the leaves as much as the wedding and the refreshments....so true!

I've wondered if there could be some night activity, so we will go out with a flashlight, and if we discover something use soapy water. I certainly don't want to kill of our lady beetles.

This has been most helpful,