University of Maryland Extension: Garden Q&A
Q: I’ve killed only a few under-sized stink bugs on my plants. Are these ones that survived over the winter (in my house)? Have we dodged the bullet this year?
A: Take a good look at those small stink bugs before you dispatch them. There are many stink bug species. Yours may be spined soldier bugs, a small brown-gray predator stink bug that eats pest insects. Its “shoulders” come to a point as sharp as a needle and even feel like a needle when touched.
Let those good guys live to do pest control for you. On the other hand, the new Asian brown marmorated stink bug that caused so much damage last summer and then spent the winter in our houses in hordes is, indeed, in the landscape now. They have mated and will lay eggs all summer which, in turn, hatch and go through five nymph stages before reaching adulthood.
As the nymphs enlarge and reach adulthood, they cause increasingly more damage with their piercing/sucking mouthparts. Young nymphs are the most vulnerable to control measures. Become familiar with them by visiting our website at www.hgic.umd.edu. The brown marmorated stink bug is an invasive species in the U.S. and is here to stay, but our controls will improve with research and experience.
Q: We have big cicada killer wasps digging nests in about a third of our yard and swarming all over the grass. Over the past three years, we tried putting permethin, bleach, and ammonia into the holes. It looks like all the wasps do is leave the treated nests and make new ones. How can we break their life cycle?
A: There are no easy control solutions for cicada killer wasps. Sounds like they have found a good habitat in full sun with well-drained soil and large trees nearby to hunt green cicadas.
Although you may see a large number, they live in solitary dens, not in colonies. Males do not have a stinger, though they try to act very intimidating. The docile female has a stinger for cicadas, but rarely stings humans unless handled.
Because these beneficials keep down the cicada population and their life span in only a few weeks, control is usually not warranted.
Cicada killer wasps like bare soil, so overseed and thicken your stand of turf this fall. You can also try running a sprinkler when you are outside in the area where the cicada killers are active. They do not like water and this may lessen their activity temporarily.
See chemical controls in our publication, “Mining Bees and Ground Nesting Wasps”: hgic.umd.edu/_media/documents/hg104_000.pdf. In ornamental beds, landscape fabric pinned down with fabric pins and covered with mulch may deter them.