Stink bugs belong to the family Pentatomidae in the order of Hemiptera: the true bugs. Stink bugs may act as pests of hemp plants. Stink bugs have piercing-sucking mouthparts which they use to pierce plant tissue. As the stink bugs feed on the host plant, they may inject salivary fluids that are toxic to the plant.
Stink bug eggs are usually found on the underside of the leaves of the host plant. Hemiptera are hemimetabolous, therefore they undergo incomplete metamorphosis. Hemipteran life cycles have three phases; these are the eggs, multiple instars of nymphs, and the adults.
There are many predators and parasitoids of stink bugs including insects in the orders Diptera, Hymenoptera, Orthoptera, Coleoptera, and Dermaptera. Arachnids are occasional predators of stink bugs as well. Two types of damage may occur to stink bug eggs: chewing and piercing. Predators may consume the eggs, while parasitoids may pierce the eggs and oviposit into the eggs of the stink bugs. Parasitoids will then develop inside the stink bug egg. Biological control of stink bugs on hemp is preferable to traditional control methods because of the limited number of pesticides that are currently legal for use on hemp.
Nezara viridula (Southern Green Stink Bug)
The southern green stink bug Nezara viridula (Linnaeus) is a polyphagous pest of many food crops in the southeastern United States. While its distribution is primarily within this region, N. viridula has established as far west as California and has even spread to the islands of Hawaii. The southern green stink bug is believed to have originated in Ethiopia. It feeds on hemp seeds, leaves, and flowers.
Egg masses of the southern green stink bug can contain as many as 130 eggs. The eggs are white to light yellow to pink and have a unique barrel shape with flat tops and lids surrounded by finger-like projections called chorial processes. The nymphs undergo five instars before molting into adults. The first instars are light yellow in color with red eyes and transparent legs and antennae. The second instar is black with a red abdomen and yellow spots on each side of the thorax. The green color of the stink bug comes during the third and fourth instars, and during the fifth instar, wing pads emerge. The abdomen of the fifth instar has a characteristic yellow-green color with red spots on the median line.
Photo by Jennifer Carr (UF/IFAS)
Adult southern green stink bugs can be identified by the small black dots that line the sides of their abdomens. To distinguish N. viridula from the green stink bug Chinavia halaris (Say), the observer should locate the stink gland pore on the sternum between the second and third legs. This pore will be short and wide in the southern green stink bug but long and curved in the green stink bug.
Biological control of N. viridula is typically facilitated by insects in the orders Diptera and Hymenoptera. In the state of Florida, the tachinid fly Trichopoda pennipes parasitizes adult and nymph southern green stink bugs. The wasp Trissolcus basalis may parasitize the eggs of the southern green stink bug, thereby suppressing populations.
For more information, see UF/IFAS Featured Creatures: http://entnemdept.ufl.edu/creatures/veg/bean/southern_green_stink_bug.htm
In North America, there are at least 20 species of stink bugs in the genus Euschistus. These stink bugs may be found on hemp, and the brown stink bug, Euschistus servus (Say), has been confirmed on hemp. All stink bugs in the genus Euschistusare predominantly brown and drab in color, but specific variations in their markings and morphology set them apart as different species. All adults of the genus Euschistus have microscopic notches on the anterolateral pronotal margins, and the humeral angles of the pronotum are acute to rounded.
E. servus (Say), the brown stink bug, is considered a very serious pest of a variety of crops in the southern United States. Its distribution in North America extends as far north as southern Canada. There are two subspecies that occur in North America: E. s. servus (Say) and E. s. eushistoides (Voltenhoven). E. s. servus has a distribution throughout the southern United States from Florida to California, and E. s. euschistoides is distributed throughout Canada and the northern United States.
The eggs of the brown stink bug are translucent and yellow, but turn light pink prior to hatching. Nymphs undergo five instars and change from brown in color to light green. Adults are a drab, gray-brown color with darkly colored markings on their backs. The genae, or cheeks, are large and pointed, and they extend past the clypeus.
Brown stink bugs are associated with the flowers and seeds of the hemp plant, and they feed using their piercing-sucking mouthparts. Parasitoid flies in the order Diptera may oviposit into the eggs of the brown stink bug. Two of these parasitoid species include Gymnosoma fuliginosa (Robineau-Desvoidy) and Cylindromyia binotata (Bigot). The wasp species Telenomus podisi (Ashmead) also parasitizes eggs of the brown stink bug.
Photo by Lyle Buss (UF/IFAS)
Close up of denticles on pronotum. Photo by Lyle Buss (UF/IFAS)
For more information, see UF/IFAS Featured Creatures: http://entnemdept.ufl.edu/creatures/veg/bean/brown_stink_bug.htm
This page was created by Sarah Birkmire, Graduate Assistant, Entomology and Nematology Department, University of Florida, IFAS (email@example.com).