Brown Marmorated Stink Bug: Field Confusion

Dorsal view; spined soldier bug, Podisus maculiventris (Say)

Dorsal view; spined soldier bug, Podisus maculiventris (Say); Photo Marlin E. Rice

Recent drought conditions have created conditions conducive to stink bug movement into fields and orchards over the past few weeks. Identifying key stink bug species is critical to making sound judgment for management decisions. There are two brown colored species that can easily be mistaken for brown marmorated stink bug (BMSB), Halyomorpha halys Stål.

One look-a-like seen in the field during the latter part of the season, easily confused with BMSB is called the spined soldier bug, Podisus maculiventris (Say). We’ve seen this insect in the field last week and should be recognized as a beneficial.

The key in identifying the differences between the two lies in the shoulders of the insects. As the name implies, the spined soldier bug has a spine on each shoulder and a black band on the primary wings at the very end of the abdomen. The BMSB has rounded shoulders lacking a banded wing pattern.

This predator is a medium-sized stink bug preying on a wide variety of arthropods, reported to feed on 90 insect species in over eight orders (De Clercq 2008), including several important economic pests.

Reported prey include the larvae of Mexican bean beetle, European corn borer, diamondback moth, corn earworm, beet armyworm, fall armyworm, cabbage looper, imported cabbageworm, Colorado potato beetle, velvetbean caterpillar, and flea beetles (Hoffmann and Frodsham 1993).

Podisus maculiventris 1st instar nymphs.

Podisus maculiventris 1st instar nymphs; Photo by Michael R. Patnaude.

The 1st instar nymph of P. maculiventris has a blackish head and thorax and reddish abdomen with black dorsal and lateral plates, similar to the BMSB 1st instar.

BMSB first instars are colored with orange or red abdomen, black head and dorsel stripes centered on the abdomen. They remain clustered around the egg mass, feeding on egg symbiont until they molt to the 2nd instar stage. Life stages of BMSB develop to an all black 2nd instar, proceeding to have striped antennae (3rd) and striped legs with shoulder spurs (4th) and wing pads (at 5th instar)

The brown stink bug, Euschistus servus (Say), another look-a-like, is equally as confusing in its close resemblance to BMSB. Yet given its pest status as a fruit feeding stink bug, its presence in the orchard would also warrant management in the orchard.

Under drought conditions, the bugs may attack fruit in high numbers. In peaches, stink bugs are also called catfacing insects. Feeding sites cause injured cells to stop growing, while healthy plant tissue continues to grow around the damaged tissue, resulting in deformities resembling a cat’s face.

Ag. Monitoring of BMSB

To determine the presence and potential threat of BMSB in NY’s agricultural systems, pheromone based trapping efforts have become the standard method to determine woodland edge populations. Cornell University faculty & staff, ENY Horticultural Program and CCE staff, in coordinated efforts, has monitored the pest since 2011. In 2015, county-based monitoring for statewide BMSB mapping include 44 sites in 14 counties placed in tree fruit orchard and vegetable field edge. Trap captures of BMSB have been followed-up by visual scouting along the perimeter rows of the orchards and field crop wooded edge. To view counties presently monitored for BMSB threshold visit http://www.eddmaps.org/bmsbny/.

2015 BMSB Trap Sites

2015 BMSB Trap Sites

We have seen an upswing in trap captures last week with increasing numbers of 3rd through 5th instar nymphs. Yet very few adults have been observed to date. However, we do expect, as in years past, to see increasing numbers of BMSB through August when nymphs and adults feed intensively to prepare for overwintering beginning in September, putting crops at greater risk.

During our trapping and scouting efforts this season we have recorded the lowest adult numbers in Tedders traps since 2011. As with the pest complex in general, the cold and prolonged spring may have taken its toll on BMSB field populations. To date we have not seen BMSB in orchard trees or extensive fruit injury from the stink bug complex.

1. De Clercq P, Wyckhuys KW, De Oliveira HN, Klapwijk JK. 2002. Predation by Podisus maculiventris on different life stages of Nezara viridula. Florida Entomologist 85: 197-202.
2. Hoffmann, M.P. and Frodsham, A.C. (1993) Natural Enemies of Vegetable Insect Pests. Cooperative Extension, Cornell University, Ithaca, NY. 63 pp.

Life Stages of the BMSB .

Life Stages of the BMSB .

BMSB Marlboro July 27th, 2015