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True Plant Bugs

Posted by Darlene Caviness

Order HemipteraTo most people, “bugs” is a generic term for insects and other creeping or crawling invertebrates.  To an entomologist, a true bug is actually a member of the Order Hemiptera.  This Order includes plant bugs, Boxelder bugs, stink bugs, lace bugs, lots of water bugs, and aphids to name only a few.  Sucking/piercing mouthparts, incomplete metamorphosis and wings that look half hard and half membranous characterize the true bugs.  In fact, Hemiptera is Latin for “half-wing.”   The membranous halves of the wings usually overlap to form a diamond shape over the bugs’ abdomen, which helps with identification.

Since this is such a large group, I will only discuss two of its damaging members.

Leaf-Footed Bug:

Leaf-Footed Bugs (Leptoglossus phyllopus) gets its common name from the flattened, leaf-like hind legs.  Adults move very deliberately, like they stepped in something disgusting and are slowly trying to shake it off.

Leaf-Footed Bug adultAdult Leaf-Footed Bugs lay barrel-shaped eggs in a single row along the undersides of leaves, often along the midrib.  The nymphs that hatch bear a passing resemblance to the adults although they are usually more brightly colored in shades of orange and red.  The nymphs molt as they grow, looking more like an adult each time.  The leaf-like leg appendages appear at one of their last molts.  Only adults possess wings. 

Where Do Leaf-Footed Bugs Feed

These herbivorous bugs may be found on a wide variety of host plants, including Junipers, Arborvitae, beans, tomatoes, sorghum, and strawberry.  They feed on twigs as well as developing fruits and nuts.  Their mouthparts pierce the plant tissue then suck out the juices.  This activity results in darkened spots, misshapen fruit, aborted nuts and wounds that allow entry of various pathogens. 

Leaf-Footed Bug nymphsHow To Control Leaf-Footed Bugs

Control should begin culturally.  Bugs hide and feed on weeds in addition to plants more desirable to humans, so controlling weeds will deprive them of habitat.  Encouraging native predators such as the tachinid fly can help control the pests.  In a home garden, lightweight row covers can help exclude the bugs from your vegetables.  Application of the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana has demonstrated >90% control of these bugs.  And there are many insecticides listed to control Leaf-footed bugs, including stylet oils, soaps, microbials, pyrethroids, carbamates, neonictinoids and organophosphates.  Remember to read the label and use all chemicals wisely.

Stink Bugs:

The term “Stink Bugs” actually comprises several different species.  Green Stink Bugs, Brown Stink Bugs, Brown Marmorated Stink Bugs and Shield Bugs look similar, but are different species.  As a group, they are quite distinctive in appearance.  Adults are shaped like a knight’s shield, while nymphs look more like upside down bowl.  They all possess glands that produce the foul smelling odor that earned them their name.

Brown Marmorated Stink Bug adultStink bugs lay clusters of 20-30 barrel-shaped eggs on the undersides of leaves.  The eggs hatch out into multicolored, rounded nymphs and begin feeding immediately.  Stink bugs molt five times before reaching adulthood and overwinter as adults.  In fact, these insects have become quite a nuisance to homeowners when they enter buildings in search of suitable overwintering sites.  In nature they often overwinter under the loose bark of dead trees, so they probably find the siding on houses a comparable substitute.  Excluding them before they become a problem is best because getting rid of them can be quite a chore. Caulk around any openings in your home and screen larger openings to prevent their entry.  If they do manage to get inside, use a vacuum cleaner to suck up the little beasties.  I also found several DIY videos on the Internet showing how to build inexpensive traps for Stink Bugs out of water and soda bottles.  However, be aware that dead Stink Bugs really stink, so you definitely want to dispose of the carcasses. 

Stink Bugs hatching

Where Do Stink Bugs Feed?

Like the Leaf-Footed Bugs, Stink Bugs have a wide range of host plants from which they feed, including vegetables, ornamentals, nuts, fruits and agronomic crops.  In fact, the brown Marmorated Stink Bug, which was accidentally introduced from Asia, has become one of the top insect pests of vegetables and tree fruits on the east coast.  They can ruin the saleability of fruits and vegetables from an aesthetic perspective as well as having an impact on fruit development itself.

 

How To Control Stink Bugs 

Control measures are similar to those for Leaf-Footed Bugs, but Stink Bugs are more ubiquitous so control is harder to maintain.  And just to make things even more interesting, there is a beneficial Stink Bug that preys on caterpillars.  Be sure to identify your bugs so you won’t kill off an ally.

Tags: Pests/Disease