Description

The redbanded stink bug, Piezodorus guildinii, is an invasive stink bug native to the Caribbean Basin and South America. Its eggs are cylindrical in shape and dark in color. They are commonly laid in parallel lines or tight clusters on stems, pods or on the undersides of leaves of host plants.

Nymphs undergo five instars, or growing stages, before transforming to adults. Individuals in early instars are oblong with a red and green forebody and an elongate, dark brown or black central marking on the abdomen. The green color becomes more prominent on later instars with the abdominal markings alternating between black and reddish brown. The entire body of older nymphs may be margined in dark reddish brown or black.

Adults are most often pale green in color but are variable and can range from brownish to purple. They have a characteristic light red band across the pronotum (top of thorax) in front of the wings. The head is small and triangular, and the antennae are pale orange. Size plays an important role in identification, as adult redbanded stink bugs are much smaller than other green stink bugs, such as Chinavia hilaris, the “green stink bug.” redbanded stink bugs are 1/3 to 2/3 of an inch (8 to 11mm) in length and 1/5 to 1/4 of an inch (4 to 6mm) in width across the pronotum. A similar species, Thyanta custator, the “red shouldered stink bug,” is easily confused with the redbanded stink bug and is not considered a serious pest. It can be distinguished by the more angulate corners of the pronotum in adults and differences in proportions and markings of nymphs. In cases where the identification is uncertain, an entomology diagnostician should be consulted.

Life Cycle

Adults emerge from their overwintering sites during spring in search of secondary hosts to feed on. Females begin laying eggs 20 days after emerging as adults. The females lay 15 to 20 eggs in two rows that are parallel on pods, leaves or stems. The redbanded stink bug always lays its eggs in two rows on the upper portion of the leaf or pod, which is unique to this species and is used as a key identifying characteristic of egg masses. Hatching usually occurs within seven days. Hatchlings remain in the nymphal state for 21 to 30 days and during this period progress through five growth stages (instars). The first stage lasts four days, and during the first two stages redbanded stink bugs are gregarious and do not inflict much damage to host plants. After the third stage, nymphs begin feeding intensively and eventually disperse. Adults may live as long as 40 days in controlled environments, such as laboratories, and between two to three months in their natural environment. Redbanded stink bugs undergo four to eight generations per growing season in Louisiana. Redbanded stink bugs are inherently mobile, with males dispersing more than females. Wind has a strong influence on dispersal, contributing to its agricultural importance.

In Louisiana, there are two to three evident peaks in population, the first peak taking place in June, the second in July and the third from August through September. Broadly overlapping generations of all life stages, where eggs, nymphs and adults are present simultaneously, have been observed only in the third peak. The increased developmental time, fertility periods and adult longevity explain the overlapping of generations during the third and final peak of the season. The presence of all life stages simultaneously can lead to extreme control failures.

Ecological Significance and Pest Status

Members of this species first appeared in the United States during the 1970s, and during 2002 it was declared a major economic pest in the southern U.S. Redbanded stink bugs cause significant damage to the leaves, stems, flowers and developing pods of soybeans (Glycine max). It is also a pest of other crops, such as wheat, other legumes, alfalfa and cotton.

Economic infestations have been reported in Louisiana since the pest’s introduction in the early 2000s. Due to their diverse host range and high mobility, Redbanded stink bugs are difficult to control. Redbanded stink bugs feed mostly on leguminous crops (Fabaceae) but also on wild plants and other row crops, such as cotton. Soybeans are the predominant host in Louisiana, and redbanded stink bugs cause significant economic damage each year. Redbanded stink bugs insert their stylets into the plant and inject salivary enzymes that break down plant tissue for feeding. This type of feeding on soybeans causes delayed maturation of pods, flower and pod abortion, and reduced yields. When the pods are marked, the seeds inside shrivel and become unmarketable. In addition, plants become more susceptible to pathogenic fungi. The redbanded stink bug is considered a late-season pest due to it specifically targeting pod development.

Control

Cultural Control. Since the redbanded stink bug is typically a late-season pest, selecting earlier maturing varieties in addition to planting early in the season may aid in controlling stink bug populations. Due to the high mobility of the redbanded stink bug, infestation of even isolated fields is unavoidable, so early planting of fast-maturing varieties may allow the crop to fully mature prior to infestation.

Chemical Control. The redbanded stink bug is not susceptible to insecticides. Insecticides that are the standard for control in other stink bug species (i.e., pyrethroid insecticides) offer only mild suppression of redbanded stink bugs. This is especially true when they are applied alone and not in conjunction with other insecticides. Bifenthrin is the active ingredient of pyrethroid insecticides, and insecticides containing this active ingredient offer the most reliable control of redbanded stink bugs. For an increased rate of control, the combination of two active ingredients is recommended. Insecticides with increased rates of acephate have shown increased efficacy in control, and the use of combinations of insecticides, acephate and bifenthrin, for example, will aid in guarding against insecticidal resistance. Insecticides used to control redbanded stink bugs have a very short residual life on the plant, typically around three days. As a result, chemical applications are often misconstrued as control failures if multiple applications are not applied during an infestation. When using insecticides, it is important to read all label instructions and to ensure that the insecticides being applied are labeled for use on the crop in which you are applying them. Consult the Louisiana Insect Pest Management Guide for the latest control recommendations for Louisiana crops. As always, consult with your local parish agent, especially when mixing insecticides for dual application.

References

Akin, S., J. Phillips, D.T. Johnson. 2011. Biology, identification and management of the redbanded stink bug. University of Arkansas Agricultural and Natural Resources Extension Document FSA7078 (accessed 19 November 2020).

Baur, Matthew, J. Baldwin. “Red-Banded Stink Bugs Trouble Louisiana.” LSU AgCenter, Louisiana State University, 12 Oct. 2015, www.lsuagcenter.com/portals/communications/publica... (accessed 18 May 2021).

Brown, S., K. Healy, N. Lord, T. Schowalter, M. Stout, T. Smith, Q. Sun, and B. E. Wilson. 2021. Louisiana Insect Pest Management Guide. LSU AgCenter Publication 1838, Baton Rouge, LA, USA. Available at: www.lsuagcenter.com/portals/communications/publica... (accessed 14 Apr. 2021).

Husseneder C, J. S. Park, A. Howells, C. V. Tikhe, and J. A. Davis. 2017. Bacteria associated with Piezodorus guildinii (Hemiptera: Pentatomidae), with special reference to those transmitted by feeding. Environmental Entomology 46: 159-166.

Temple, J. H., J. A. Davis, S. Micinski, J. T. Hardke, P. Price, and B. R. Leonard. 2013. Species composition and seasonal abundance of stink bugs (Hemiptera: Pentatomidae) in Louisiana soybean. Community and Ecosystem Ecology 42: 648-657. Accessed 19 November 2020.

Temple, J. H. 2011. “Redbanded Stink Bug, Piezodorus Guildinii (Westwood): Pest Status, Control Strategies, and Management in Louisiana Soybean.” Ph.D. Dissertation, LSU Digital Commons, 148 pp., https://digitalcommons.lsu.edu/cgi/viewcontent.cgi... (accessed 18 May 2021).