By Gladis M. Zinati, Ph.D., Associate Research Scientist
The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), native to Japan, South Korea, and China, has emerged as one of the most devastating pests of northeastern United States agriculture. Since its introduction in the mid-1990’s to Allentown, PA, BMSB has spread across North America and is now present in 41 states and eastern Canada, causing the greatest crop damage in the mid-Atlantic region and a homeowner nuisance. In 2006, BMSB caused severe damage in fruit trees in NJ and PA and high numbers were found in soybeans and ornamentals. In 2010, high populations of BMSB severely damaged tree fruit orchards, with up to 90% of the peach crop at some mid-Atlantic farms damaged and an estimated $37 million loss to other mid-Atlantic tree fruit. Due to diverse host plants, BMSB has established itself as a primary pest in tree fruit crops and population pressure currently remains high.
BMSB adults are relatively large compared to other stink bugs, measuring 1/2 - 2/3” long and 5/16” wide (Photo 1). Their name “marmorated” means banded or streaked, as in their appearance. The two white bands on their antennae, the black and white banding on the abdomen, the smooth shoulder, and the mottled brown legs are distinguishing characteristics of BMSB that can help differentiate them from native stink bugs.
BMSB adults and nymphs use their straw like mouthparts to feed on the internal plant tissues. The action of sucking out the juices from fruits, vegetables, and seeds creates cork-like pockmarks and deformations that make fruits (such as apples, peaches, and pear) and vegetables (tomato, pepper, sweet corn) unmarketable.
In the spring, BMSB adults emerge from overwintering sites (houses, barns, storage buildings, and dead trees) and become active on nearby crops such as peach, hardwood trees, and shrubs during warm sunny days. Adult BMSB have the capacity to fly more than a mile and some have been shown to have the ability to fly over 31 miles. In the spring and throughout the summer, BMSB adults feed, mate, and lay eggs. The adult female BMSB lays barrel-shaped, white to pale-green eggs in clusters of 28 eggs on the underside of plant leaves. The BMSB female can lay 4-10 egg masses in her lifetime. BMSB have five nymphal growth stages, known as instars.
The first instar BMSB nymphs have an orange abdomen with brown rectangular markings. As the nymphs get older, they show banded antennae and legs with rust-colored abdomen and broad brown markings. Development from egg to adult takes approximately 32-35 days, and as adults and all nymphal instars can feed and cause injury to their hosts. Nymphs and adults can be found on a wide range of plant species that bear buds, pods, and fruiting bodies. Their wide range of hosts include soybean, sunflower, cayenne pepper, tree of heaven, eggplant, tomato, Swiss chard, corn, cherry, moth orchid, mimosa, mulberry, and crabapple.
Monitoring and Management Tactics
The large host plant range, its high mobility, and lack of natural enemies make monitoring this pest in both conventional and organic agricultural systems a critical, yet challenging task. In October 2012, Dr. Anne Nielsen, an Extension Entomologist at Rutgers University, and collaborating institutions including Rodale Institute were awarded a grant funded by USDA – NIFA OREI program # 2012-51300-20097, entitled, Whole-farm Organic Management of BMSB and Endemic Pentatomids through Behavior-based Habitat Manipulation.
As part of a multi-state project, Rodale Institute participated in the investigation of the temporal and spatial movement of BMSB and native pentatomids and their aggregation in order to identify potential organic pest management strategies.
In 2012 and 2013, we investigated overwintering structures and fabrics, cone traps on wooden pyramids, trap crops, and overwintering bug houses to better understand stink bug dispersal and aggregation. Below are the details and results of these tactics:
Overwintering structures and fabrics
In November of 2012, we surveyed structures such as buildings, offices, attics, sheds, greenhouses, barns, and garages at Rodale Institute for overwintering BMSB and recorded the number of dead and live adults per structure. We found living overwintering BMSB adults in the book store, the Siegfriedale House, and the pavilion. Within these structures we also identified fabrics in which BMSB preferred to hide and overwinter. Overwintering BMSB were generally found hiding in dark-colored and water proof rain coats and black fabric “Grow Bags” (Photo 4).
Cone traps on wooden pyramid
After an overwintering period, in the early spring BMSB adults emerge from wooded areas and human-made structures and begin feeding (sucking) on green plants to nourish themselves and mate in spring. They then moved to crops such as peaches, followed by berries, tomatoes, and peppers, and finally to apples and field crops.
To monitor the temporal and spatial dispersal of BMSB adults from the overwintering structures to nearby outdoor areas, in the Spring 2013 we set up four cones traps each attached to black wooden pyramids.
A combination of vapor tape (to kill bugs) and pheromone “Dead-Inn” traps from AgBio were placed within the cones. The traps were deployed on each side the Siegfriedale House (four cardinal directions). The house is surrounded by wooded area from the north and small herb and vegetable garden from the west .
Between April 18 and June 10, we collected and recorded bugs trapped in the cones twice a week. Our first BMSB adults (four females) were collected in the west trap on May 20. Four and 10 days later, two male adults were also caught in the west side cone trap. By June, more males and females were seen in the east and south cones.
Early June of 2013, we tested five different plant species (admiral pea, sorghum, sunflowers, okra, and millet) as potential trap crops. We assessed the relative attractiveness of these different potential trap crops to BMSB by monitoring and recording BMSB abundance and life stages per crop. There were five rows of each plant species per 20 ft x 10 ft plot and five replicate plots for a total of 25 plots planted in Latin square design.
Monitoring BMSB: by crop and direction
Admiral pea flowered and died quickly before BMSB monitoring started. During weekly monitoring, we did not see any BMSB egg masses, nymphs or adults until August 21, 2013. On September 4th the first BMSB adult and nymphs were seen on fruit heads of sunflower, millet, and sorghum. Adult spined-soldier stink bugs (a natural enemy) were observed on millet, sunflower (Photo 9), okra, and sorghum towards the south of plots, near the woods. The last BMSB adult was observed October 2nd on the east side of sorghum (which was senescing) in a plot close to the wooded area.
It is important to note that beneficial insects (natural enemies of BMSB) (Photo 11) such as katydid, spiders, lady bugs, praying mantid, and wasps were also found on the plants where BMSB adults and nymphs were feeding.
Overwintering shelter trap
We participated in a multi-state project to monitor BMSB adult preference for overwintering location and cardinal direction of overwintering structures. The idea was to use materials that are commonly found on farms to create a shelter to “trap out” overwintering BMSB. Based on our scouting record from fall 2012, we identified two structures to setup and deploy overwintering BMSB shelter traps: the pavilion and the Siegfriedale House. These two structures are bordered with wooded area and organic crops. The shelter traps were made of wood, coated with white weatherproof paint and stuffed with 1m2 of used row cover.
We deployed the shelter traps on September 16, 2013. Four traps were placed outside and four inside on each side of the two selected structures.
On November 8, 2013, we checked and counted BMSBs in trap houses. At the garden pavilion, in outdoor houses, overwintering female adults were concentrated in the east side, followed by the south and west side. Interestingly, only one male adult was found in the trap house located on the northern side. Indoor, however, female adults were in the north and west houses and the male adults were on the south and east side. At the Siegfriedale House, BMSB adults were not seen in either the outdoor or indoor trap houses.
Conclusions and Recommendations
The brown marmorated stink bug (BMSB) feeds on a diverse array of crops, damaging a variety of fruits and vegetables, and significantly impacting farmer profits, particularly in the mid-Atlantic region. Populations of this pest may increase with food availability, warm climate, sunny days, absence of natural enemies, and lack of management.
Organic farmers should scout their homes and farm structures during the fall/winter season to discover overwintering sites for BMSB adults. In the spring, growers can monitor for BMSB using observational sampling. Additionally, growers can set up pheromone traps, such as the “Dead-Inn” trap from AgBio or the stink bug trap from Rescue.
After testing multiple plant species as potential trap crops for BMSB, we have identified sunflower and red sorghum to be two crops that are highly attractive to BMSB. These two crops are tall, brightly colored, and have seeds that are good protein sources. Thus, planting these two plants as trap crops around the perimeter of a cash crop may reduce BMSB movement into and percent injury on the cash crops. Additionally, these trap crops attract and provide resources for natural enemies (i.e. katydid, lady beetle, and wasps), which may help enhance their populations and naturally reduce BMSB abundance. The integration of these management strategies have wide appeal for reducing crop losses for both organic and conventional farmers.
We are currently testing the effectiveness of using sunflower and sorghum as trap crops to manage BMSB population in organic cropping system and increase marketability of pepper cash crop. Stay tuned for future information on this topic.
For information related to this article contact Dr. Gladis Zinati at email@example.com
This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2012-51300-20097, titled: Whole-Farm Organic Management of Brown Marmorated Stink Bug (BMSB) and Endemic Pentatomids through Behavior-Based Habitat Manipulation, from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture. This article was approved of by Dr. Anne Nielsen, Rutgers University prior to publishing.