Jun 26, 2017

Brown marmorated stink bug monitoring, management crucial

A Penn State University Extension tree fruit entomologist issued a communication informing growers it is time to start again seriously plan for the activities related to the monitoring and management of the brown marmorated stink bug (BMSB).

Grzegorz (Greg) Krawczyk said the BMSB monitoring lures and traps from Ag-Bio Inc., AlphaScent Inc., Sterling International, and Trece Inc. are commercially available either directly from the manufacturer, specialty stores or stores like Walmart, Lowe’s or Home Depot. Although different lures and trap designs are available, all of them should provide adequate information about the presence or absence of the stink bugs and potentially about the necessity of a specific stink bug management treatment. 

The most popular BMSB traps are the clear plastic sticky traps and the pyramid-shaped traps with a bug capturing container. The clear sticky traps are very effective in monitoring BMSB adults but are not as effective in monitoring BMSB juvenile stages. The container-based traps are initially more difficult to assemble (and more expensive) but, if placed in direct contact with a vegetation, they will provide very accurate monitoring for both, BMSB nymphs and adults. Additionally, under higher pressure from stink bugs, the container traps can be easily emptied from collected stink bugs and reused, while the sticky traps will need to be replaced. Although each trap and lure combination vary in the efficacy of captured stink bugs, all of them are an excellent source of information about the actual local presence of BMSB.

The BMSB adults are strong migratory pests, capable of moving long distances and aggregating in any location. Newly arrived BMSB adults, if not detected and controlled, are capable to cause serious fruit injuries in orchards.

Unfortunately, since the injuries caused by the BMSB adults are difficult to detect until about 10-14 days after the feeding, often the stink bugs may be already gone from the site before the feeding symptoms are detected. On another hand, the detection of BMSB nymphs in traps almost always warrants the necessity of immediate BMSB control, likely with an effective insecticide application.

Brown marmorated stink bug nymphs, in contrast to BMSB adults, are resident pests in the orchard. If the BMSB nymphs are not controlled, starting from the second instar, they will continuously feed and unfortunately, every time nymphs are feeding, the fruit injury is created, which will result in deformed fruit and/or corky area just under the skin of the fruit. As with most insects, the BMSB nymphal development is weather depended but usually it takes about five weeks for the BMSB nymph to become adult.

 The list of effective insecticide options is limited and includes products only with few distinctive modes of action: pyrethroids (IRAC Group 3A): Bifenture EC and 10DF and Brigade WSB (the same active ingredient, bifenthrin), Danitol (fenpropathrin), and Warrior (cyhalothrin); neonicotinoids (IRAC Group 4A): Actara (thiametoxam), Assail (acetamiprid), Belay (clothianidin) and Venom and Scorpion (the same active ingredient – dinotefuran) ; one carbamate product (IRAC Group 1A), Lannate (methomyl) and some products including combinations of two different insecticide chemistries such as in Endigo or Leverage.

While trying to limit the impact of BMSB on fruit, please remember about potential negative impact of BMSB effective insecticides on various beneficial organisms and native bees present in the orchard, seasonal limits for the number of insecticide applications per season and the mandatory pre-harvest intervals of various products, Krawczyk said.

Photo above:  Clear sticky trap with BMSB adults (Fall 2016) Photo: G. Krawczyk, Penn State

 Source: Penn State University Extension