An ambush bug decides to pass on the bumble bee on a coneflower.
Photo courtesy of the NC Cooperative Extension
I spend a lot of time in my garden just looking at things. Looking at the flowers and foliage, of course, but also looking closely at the plants to see what insects might be on them. I try to avoid insecticides in my garden, because I have honey bees and I also want to protect the butterflies and other pollinators that visit the flowers for pollen and nectar. Many birds feed directly on flowers, such as goldfinch, which will sit on a purple coneflower stem and feast on the seedhead, and other birds may catch a caterpillar feeding on a flower to feed their babies.
The other day I spied a newly hatched cluster of leaf footed bugs on a rose leaf. Leaf footed bug adults are largish insects, brown with a white lateral band across the back, and distinctive flattened appendages on the back legs that look like a leaf. They are a problem on many plants, for example their feeding on tomatoes causes hard white spots on the fruit. As a nymph (very young insect) they look quite different: bright red bodies with black legs and black antennae.
I felt a little bad when I decided to knock the entire cluster into a jar of soapy water, immediately killing them. Before I did that, however, I double checked to ensure they were indeed leaf footed bug nymphs and not their closely related, and entirely beneficial cousin, the assassin bug. The assassin bug is a predatory insect, feeding primarily on soft bodied insects such as aphids, white fly, and caterpillars. There are several different species of assassin bugs, and for those interested in a natural, low input garden it’s worth taking the time to familiarize yourself with some of the more common species. There are many predators in the Order Hemiptera (the “True Bugs”).
For example, there are several predatory stink bugs. The Florida predatory stink bug, with its striking black and red coloring, is easy to recognize as something different from the brown or green stink bug pest. On the other hand, the spiny soldier bug looks very like a brown stink bug; the somewhat more elongated shield shape and pointy “shoulders” are subtle clues that it is friend not foe. The spiney soldier bug feeds on caterpillars and beetle grubs, often going after prey larger than itself. Then there’s the ambush bug. The ambush bug is a stout insect, with a large head and bulky front legs. The ambush bug typically has mottled coloring, the better to camouflage it while it lies in wait for its prey. Both pest and predator insects in the order of True Bugs feed by inserting their long proboscis (an elongated, sucking mouthpart), into a plant or insect, and sucking the juices, rather than eating with mandibles (moving mouth parts). Predatory insects in this order have a shorter, more stout proboscis, the better to insert into the body of its victim.
Ladybugs are wonderful predatory insects that most people recognize. There are numerous species, with different shades of red and different numbers of black spots. They are great predators of aphids and other soft bodied insects. The larval form, typically black with orange or red spots, which looks something like a tiny alligator, is actually an even better predator than the adults, but are often unrecognized as a helpful insect in the garden. Ladybug eggs are bright yellow footballs, stacked on end, in clusters. If you see them on a leaf, be sure to leave them!
Another sign of beneficial insects I love to see are the eggs of green lacewings. Not to be confused with lacebugs (an awful pest of azaleas), green lacewings are a lovely shade of light green with “lacy” wings along its extended green body, long antennae, and large eyes. The larvae are somewhat similar in form to ladybug larvae, but are light brown and white rather than black. The eggs are fun to spot: a single tiny, white egg, suspended at the end of a stiff, hair-like thread above a leaf. A sign that there will soon be help with insect pests!
Another general way to determine if an insect is a predator is they tend to have quick movements (to better pursue prey), and are solitary. That was one clue that helped me identify the leaf footed bug nymphs, since they were in a cluster.
Learning to identify the “good” and “bad” insects in the garden is a great way to learn more about the web of nature and also entice kids into the garden – they tend to enjoy insects once they get past the “ick” stage.
If you have insect id questions, give us a call at NC Cooperative Extension, Richmond County Center, at 910-997-8255. Follow us on Facebook or visit our website, Richmond.ces.ncsu.edu.