The southern green stink bug, Nezara viridula (Linnaeus), is in the order Hemiptera or “true bugs.” Stink bugs are in the family Pentatomidae and adults are recognized by their shield-shape, five-segmented antennae, and their malodorous scent. The southern green stink bug is a highly polyphagous feeder, attacking many important food crops.
The southern green stink bug is believed to have originated in Ethiopia. Its distribution now includes the tropical and subtropical regions of Europe, Asia, Africa and the Americas. In South America, it is expanding its range to Paraguay, south Argentina and toward the north-east of Brazil, due to expanding soybean production (Panizzi 2008). In North America, it is limited primarily to the southeastern United States, Virginia to Florida in the east, Ohio and Arkansas in the midwest, and to Texas in the southwest. It is also established in Hawaii and California (Capinera 2001).
The adult is shield-shaped with an overall dull green color. The eyes are dark red or black. Small black dots can be found along the sides of the abdomen. The wings completely cover the abdomen. The males average 12.1 mm in length and females 13.15 mm in length. Copulation may last a few minutes to a few days. Females can lay eggs three to four weeks after becoming adults. The average female lays one egg mass but production of two egg masses is not uncommon. A female southern green stink bug could lay as many as 260 eggs over her life span.
Eggs have been found as early as the second week of April and as late as December 12th. The eggs are deposited in masses that range from 30 to 130 eggs per mass. The female oviposits on the undersurface of leaves in the upper portions of canopied crops and weeds. Weeds that are favored by the southern green stink bug include beggerweed, rattlebox, Mexican clover, wild blackberry and nut grass. The eggs are firmly glued together and to the substrate. The eggs are white to light yellow in color and barrel shaped with tops that are flat with a disc shaped lid. There are 28 to 32 finger-like projections around the lid called chorial processes. The egg is 1/20 of an inch in length and 1/29 inch wide. The incubation time for the eggs is five days in the summer and two to three weeks in early spring and late fall. As incubation continues the eggs turn pinkish in color.
The southern green stink bug has piercing-sucking mouthparts. The mouth consists of a long beak-like structure called the rostrum. Salivary fluid is pumped down the salivary duct and liquefied food is pumped up the food canal. All plant parts are likely to be fed upon, but growing shoots and developing fruit are preferred. Attached shoots usually wither, or in extreme cases may die. The damage on fruit from the punctures is hard brownish or black spots. These punctures affect the fruit’s edible qualities and decidedly lower its market value. Young fruit growth is retarded and it often withers and drops from the plant. In addition to the visual damage caused by southern green stink bug feeding, the mechanical transmission of tomato bacterial spot may also result.
Parasites, usually wasps and flies, provide biological control of the southern green stink bug. In Florida a tachinid fly, Trichopoda pennipes, parasitizes adults and nymphs; and a wasp, Trissolcus basalis, parasitizes eggs. These two parasites have also been introduced as biological control agents in other areas, such as Australia and Hawaii, to control the southern green stink bug. California used T. basalis in an effort to control its southern green stink bug population.
The use of trap crops is not a widely accepted idea for control of the southern green stink bug, but it has excellent potential as a type of control. The choice for trap crops in the summer would be leguminous plants such as cowpeas and beans. In the late fall and early spring cruciferous plants are recommended. The trap crop should be sprayed or plowed under before the developing southern green stink bugs become adults to prevent them from migrating to the main crop. Insecticides are commonly applied at blossom and fruit formation.