Do I Squash It?
Identifying Your Garden Guest
We have had multiple people come into the NHC Extension Plant Clinic asking about little orange bugs in their garden, especially on tomatoes. The question has been ‘are these bad or beneficial?’ Are they stink bugs or assassin bugs? (Spoiler-they have been ‘bad’ bugs)
Assassin bugs, more specifically the milkweed assassin bug, are beneficial insects. They will feed on various prey in yards and gardens, including some we would be glad to be rid of (i.e. mosquitos, cucumber beetles and army or rootworm caterpillars). Leaffooted bugs (genus Leptoglossus) are a type of stink bug that prefer to eat our garden produce. It is difficult to tell the difference between the leaffooted bug nymph and a milkweed assassin bug nymph. Both appear orange with long dark legs. But it’s all in those legs; look closely at the back ones. Leaffooted bugs received their common name based on the morphology of their back legs. They have what looks like a little leaf, or bell-bottom. This can be seen on the nymphs as well, especially later stages, if you can get a close look. (See Figures 1 and 2 for leaffooted bugs, Figures 3 and 4 for assassin bugs)
It’s important to identify the insects as you will be happy if you have the beneficial assassin bugs and you will want to leave it alone. But what if you identify it as leaffooted bugs? Well, then you may feel unhappy, but don’t despair, there are a few things you can do to manage them.
Managing Leaffooted Bugs
There are various integrated pest management steps to take for leaffooted bugs, starting with letting nature take its course. If they are not overwhelming you, let them be. Other predators, birds, spiders or even assassin bugs, will help take care of them.
Lessen the attractiveness of your yard to them. Remove overwintering sites where possible, such as woodpiles or palm fronds. Eliminate weedy areas or keep them mowed. The leaffooted bugs will hang out in those spaces as it will provide food for them until dinner is ready in your vegetable garden.
Squash them (there are multiple methods). Use your hand, use a leaf, grab the adults in your hand, shake them silly, throw them on the ground and stomp on them, but be quick, adults fly.
Chemical control is rarely warranted for leaffooted bugs in our home gardens. The damage is usually tolerable, but if needed, try to watch for the nymphs and target them. Neem or horticultural oil is a less toxic option that may control or repel nymphs. Other choices include pyrethroids or malathion. These chemicals are toxic to bees so be sure to read the label directions for proper application methods. If you spray these in a vegetable garden, note the pre-harvest interval, or the time to wait between spraying and harvesting.
So What About those Tomatoes in my Garden?
Accept a bit of loss in production. If it is from leaffooted bugs, accept a bit of damage from those nymphs you didn’t catch (see Figures 5 and 6). The tomatoes can still be used, even with the insect damage. You can always cut off any unsightly parts, or if you use them in a sauce, no one will know that a bug has been sharing the tomato with you, right?
For more detailed information on leaffooted bugs as well as assassin bugs, see the referenced URLs.