Brown marmorated stinkbugs (Halyomorpha halys) are coming back! The chaotic winter weather – cycles of below-zero temperatures, snow and consequent warm spells –in most of the United States did little to kill-off the over-wintering population of brown marmorated stinkbug (BMSB). While early reports speculated on the extreme cold weather and snow killing the BMSB, recent spring reports show that they are primed for a comeback to commercial as well as home garden plantings.
“We are not seeing any difference in the mortality rates” because of the cold, said Tracy Leskey, the department's research entomologist in charge of the Stop BMSP project. “We haven't seen any effect so far,” she added. BMSB infestations have now spread to 41 states and several European countries having lived through the super-cold and snowy winter by making their own anti-freeze-type substance within their “blood” system that allows them to survive down to -5°F. They also invade houses, barns and sheds looking for a winter home that prevents freezing.
Pheromone traps are one way home gardeners have of outwitting BMSB and their devastation. Pheromone traps work by attracting insects such as the BMSB to traps from which they cannot escape. Pheromones are chemical substance produced and released into the environment by insects and other animals. They are specific to affecting certain behaviors and the physiology of others of its species.
Most pheromone traps use a mixture of pheromones to attract both males and females. RESCUE!® recently received a patent on the pheromone murgantiol which influences gathering together of the bugs (aggregate gathering). This chemical mixed with other pheromones has the effect of attracting more BMSBs throughout the spring and summer seasons.
For the latest information about brown marmorated stink bugs (Halyomorpha halys) visit Stop BMSB, a website that deals with the biology, ecology, and management of the BMSG. The site is the joint effort of the team of researchers funded by the United States Department of Agriculture (USDA) Specialty Crop Research Initiative.
Life Cycles of Brown Marmorated Stink Bugs
Identifying and then knowing and understanding the life of the BMSB is the first step in devising a control plan. BMSBs leave hibernation in April and May as weather warms and one of their first responses is to mate. Pheromone-baited traps are useful for monitoring populations or control from early spring through summer months until the end of August into September. Pheromones are chemical substance produced and released into the environment by insects and other animals that influence behavior. It is important to maintain pheromone traps throughout the summer months to capture as many juveniles as possible. Cooler months of September and October push BMSBs to seek shelter for overwintering. Pheromone traps cease working. Pheromone traps usually contain a mixture of pheromones to attract both males and females. RESCUE!® (a member of the Sterling Company) recently received a patent on the pheromone murgantiol which has a synergistic effect with the combination currently used.
BMSBs feed from over 150 different kinds of crops
BMSBs are not picky eaters says Tracy Leskey, Ph.D., research entomologist with the USDA Agricultural Research Service Appalachian Fruit Research Station, in Kearneysville, West Virginia who is also leading the national team of scientists battling the brown marmorated stink bug. They feed on apples, peaches, corn, peppers, tomatoes, grapes, and raspberries, as well as soybeans and forage crops. Scientists recently published a list of 170 plants that the (BMSB) uses for food and reproduction. Host Plants of the Brown Marmorated Stink Bug in the U.S. is a “living” publication updated regularly on the web," said North Carolina State University researcher Jim Walgenbach, one of the scientists who contributed to the project. The list includes many ornamental as well as food plants. Among the ornamental and native plants are trees such as Acer (Maples), Aesculus (Horse Chestnuts), Ailanthus (Tree-of-Heaven), Amelanchier (Service Berry), Betula (Birches), Cercis (Redbuds), Cornus (Dogwoods), Crataegus (Hawthorne), Gleditsia (Honey Locust), Juniperus virginiana (Red Cedar), Magnolia (Magonolias), Prunus (Ornamental Cherry Trees), Quercus (Oaks), Stewartia (Stewartias), Tilia (linden and basswood).
Proper Positioning of Pheromone Traps
Outdoor pheromone-baited traps should be in place as soon as weather warms and the BMSBs leave overwinter hibernation and monitored over the summer months. In some regions this will be as early as April 1 - no April Fool's joke. By the time homeowners see numbers of stinkbugs, it is difficult to trap enough to reduce damage. Monitor pheromones in traps and replace when needed. The initial pack included with a brand-new trap is good for 30 days; replacement packs are good for 90 days. Most pheromone traps use a mixture of pheromones to attract both males and females. RESCUE!® recently received a patent on the pheromone murgantiol which is a known aggregation pheromone for many kinds of stink bugs. Sterling synthesized and tested the molecule on the Brown Marmorated Stink Bug (BMSB) and found it has a similar effect on BMSBs. Sterling synthesized and tested the molecule on the Brown Marmorated Stink Bug (BMSB) and found that murganitol combined with pheromones already used in traps has an effect much more effective than previous combinations. Murgantiol has been included in pheromone traps combinations since 2013.
Position Pheromone Trap on Trees with Newly Emerging Foliage
Place traps in trees and bushes where emerging bugs like to mate. Secure traps so that both top and bottom make contact with the plant. This allows the traps’ vanes (wing-like appendages) to serve as ramps for BMSBs, including immature ones. Attracted by the pheromones, they climb into the trap. Once in the trap, they are unable to escape, dry up, and die. RESCUE!® Stink Bug Traps lure BMSBs within a 30-foot radius by using combinations of many pheromone attractants. The stink bugs crawl or fly to the trap, walk up the green ‘fins’ and through the cone, and are trapped inside the clear chamber where they dehydrate. RESCUE!® researchers estimate that for every female stink bug trapped during mating season, a potential 400 stink bugs are eliminated. To be effective, keep pheromone packs in traps up-to-date. Packs included with newly purchased traps are good for 40 days; replacement packs are good for 90 days.
Space Pheromone Traps Properly for Best Results
Proper placement of pheromone traps stresses keeping the trap upright and keeping trap out of dense foliage for successful dispersal of pheromones. Attach trap to secure the bottom corners of the fins to branches or have leaves touch lower half of the trap's green fins so wingless nymphs (immature bugs) can enter trap. Expose the trap’s upper half to air and sun. (Additional twist-ties are supplied with new traps to secure the bottom corners of the fins to branches.) Set up a perimeter around vegetable gardens by placing traps 20-30 feet apart along the garden's edge. In this case, secure both the top of trap and bottom fins to a stake or pole so both stink bug adults and nymphs may easily enter the trap. Placing traps about three feet off the ground keeps the scent plume dispersing properly in a downward and outward fashion for about 30 feet.