Posts Tagged ‘brown marmorated stinkbug’

Brown Marmorated Stink Bug in Peppers

Friday, August 31st, 2012

Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu

There has been a large and rapid increase in brown marmorated stink bug (BMSB) in some pepper fields in the past week in central Maryland. Numbers just two weeks ago in these areas were very low with just a few nymphs observed. We know that BMSB populations tend to increase in August and through the fall into the first frost, but this was such a rapid increase that a great deal of damage was done to bell and banana peppers.

These peppers had been treated with chlorantraniliprole (Coragen) and this took care of any worm problems very well, but the growers did not think stink bug. There were 8-10 nymphs and 2-3 adult BMSBs per plant in these fields. Damage to peppers as you might guess was extensive (Fig. 1). Much of the feeding appeared to be done by nymphs (Fig. 2). BMSB nymphs have a white stripe on all six of their legs, which is unique compared with our most common native stink bug species. This white stripe fades when nymphs become adults.

Besides the white ‘cloudy spots’ on fruit, many peppers had dark brown and red as well as bright white areas (Fig. 1). These bright white areas were found to have yeast growing within the wound that from previous studies we learned has been injected by the BMSB when it feeds.

One odd thing from the BMSB outbreak was that tomato fields that were next to or very close to the pepper fields had almost no BMSBs in them. Whether this would have changed soon we are not sure as the growers did not take any chances and treated.

 Figure 1. BMSB damage to bell and banana pepper, brown spot (yellow arrow) and bright white areas (green arrows)

Figure 2. BMSB nymphs feeding on pepper

Stink Bugs are Bad in Some Tomato Fields – But it is Not BMSB

Friday, August 17th, 2012

Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu

I have seen a great deal of stink bug damage to tomato fruit this year-more than usual (Fig. 1). The fruit has the characteristic white spots that when peeled back reveal spongy white areas. As the fruit turns red these white areas turn yellow (Fig. 1). When adults, or especially nymphs, feed on the fruit they create a star burst pattern in the surface of the fruit. I guess the surprise is that I have found very few if any Brown marmorated stink bugs (BMSB) in any of these tomato fields. Almost all of the stink bugs have been brown stink bugs (Euschistus spp), although lately (last 2 weeks) I have seen more green stink bugs. There have been very few reports or observations of BMSB being much of a problem so far this year in vegetables. Adult brown stink bugs are grayish-yellow to light brown with dark punctures on their back (Fig. 2). They DO NOT have two white spots on their antenna as do BMSB. Adults overwinter in woods, fence rows and under the bark of trees. A female oviposits a total of about 60 eggs over the summer. The nymphs, which are pale green, develop through five instars and require about one month for development. Because the adults are strong fliers they rapidly can move between hosts. Brown stink bugs are very difficult to scout for and often the only thing that is seen is the damage they cause to large green or ripening fruit. Stink bugs are difficult to control even when found as it takes several applications of insecticide to reduce their numbers (see the Commercial Vegetable Production guide for recommendations). Some of the most heavily fed upon fruit had very dark areas that when cut into appear as a dry rot (Fig. 3). What microorganisms are in this dry rot area is something we are looking into. It appears that our native stink bugs can inject microorganisms almost as readily as do BMSB when they feed.

Figure 1. Stink bug feeding on tomato, yellow areas when cut reveal spongy white cells

Figure 2. Brown stink bug, Euschistus, spp.

Figure 3. Internal dry rot caused by very heavy stink bug feeding

Fruit Crop Insects – July 27, 2012

Friday, July 27th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Spotted Wing Drosophila
Over the past couple of weeks, we have started to find spotted wing drosophila adults in traps placed in 6 locations throughout the state. The following new publications were recently developed by specialists at Penn State University and the University of Maryland.

Spotted Wing Drosophila, Part 1: Overview and Identification
http://pubs.cas.psu.edu/FreePubs/PDFs/xj0045.pdf
Spotted Wing Drosophila, Part 2: Natural History
http://pubs.cas.psu.edu/FreePubs/PDFs/xj0046.pdf
Spotted Wing Drosophila, Part 3: Monitoring
http://pubs.cas.psu.edu/FreePubs/PDFs/xj0047.pdf
Spotted Wing Drosophila, Part 4: Management http://pubs.cas.psu.edu/FreePubs/PDFs/xj0048.pdf

Brown Marmorated Stinkbug
Emergency Exemption (Section 18) for BMSB Control in Apple, Peach, and Nectarine – On Friday, July 20, 2012, the EPA approved our Sect 18 request for the use of the pesticide bifenthrin on apples, peaches, and nectarines to help manage populations of the brown marmorated stink bug. The only bifenthrin products allowed under this Sect 18 are Brigade WSB (FMC’s product), Bifenture EC and Bifenture 10DF (United Phosphorus, Inc. products). Please see the attached copy of the approval letter from EPA for use directions, rates and restrictions: http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2012/07/12DE04signedauthorizationBifenthrin.pdf. You will also need a copy of the label before making any applications. The Section 18 label for Brigade is available online: http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2012/07/26Jul2012BrigadeBSMBSection18DE.pdf. Please contact Dave Pyne at the Delaware Department of Agriculture or Joanne Whalen for more information.

Section 18 for Brown Marmorated Stink Bug (BMSB) Management on Stone and Pome Fruit Approved

Friday, July 6th, 2012

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Our Section 18 request for the use of dinotefuran (Trade Names: Venom from Valent U.S.A. Corporation; Scorpion from Gowan Company, LLC) to control BMSB on stone and pome fruits has been approved by EPA. This use expires on Oct 15, 2012. Please refer to this link: http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2012/07/12DE0708authorization.pdf for more information on use rates and restrictions. You should also have a copy of the label in your possession before making an application so please contact either David Pyne at the Delaware Department of Agriculture (David.Pyne@state.de.us) or Joanne Whalen (jwhalen@udel.edu) for more information. 

Sure Looks Like Brown Marmorated Stink Bug Damage – But It Isn’t

Friday, August 26th, 2011

Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu

Over the last few weeks growers have given me damaged pears that at the time I said looked like brown marmorated stink bug damage. Pears on the outside had pits in them where it looked like the bug had fed at one time (Photo 1). When the fruit is cut open there is a brown spot deep inside the pear that looks like brown marmorated stink bug (BMSB) feeding damage (Photo 2). But this spot differs from BMSB feeding in a couple of ways. First it is extremely hard, it is almost impossible to get a knife through it. Almost all of the BMSB damaged pears and apples and other fruit where I have seen a brown spot may be pithy or mealy or firm, but it has never been really hard. Second no yeast was found associated with the spot. In almost every case of BMSB feeding resulting in a dark spot in the fruit we have found yeast. And thirdly there was no stylet wound found in the damaged areas. I have found that if the cut is made into the fruit to the brown spot that the brown spot will then swell in a short time and stick up from the surface of the cut fruit (Photo 2).

The most likely cause of the damaged pear fruit appears to be Stony Pit disease, but even this we are not entirely sure. One problem is that the causal agent of Pear Stony Pit has yet to be isolated, but it can be transmitted by grafting and therefore a virus seems to be the most likely suspect, but no one knows for sure. Insect vectors or infected seed have not been documented as transmission factors for the virus.

The symptoms usually start about three weeks after petal fall, when dark green spots form on the fruit. The areas around these spots continue to grow, but the spots themselves do not. This results in misshapen fruit with pits (Photo 1). Pits often become necrotic and the fruit beneath becomes hardened (Photo 2). If fruit is heavily pitted it may become so hard that it is difficult to cut with a knife. Cracking of the bark, stunting of trees and chlorotic vein-banding have also been reported. One of the very odd things about this “disease” is that symptoms on fruit vary from season to season as well as severity. Trees that show symptoms one year may have no pitted fruit the following years. This type of scenario resembles damage more from BMSB feeding than a virus disease, which makes the diagnosis that much more difficult.

The best management practice seems to be to select virus-free trees for planting. Some of the most severely infected cultivars include Bosc, Comice, and Seckel, while less pronounced symptoms are found on Hardy, Conference, Forelle, Howell, Old Home, Packham’s Triumph, Bartlett, and a few other cultivars.

This is NOT MEANT TO SAY BMSB has not caused severe damage in the mid-Atlantic on fruit and vegetables because it has, just that fruit damage can be attributed to BMSB (as I did) when it was not the causal agent. Stony Pit seems to be fairly common this year in pears and any damaged-pitted fruit should be examined carefully.

Photo 1. Pear fruit with deep dimple in center caused by Stony Pit disease

Photo 2. Dimple area cut open showing extremely hard, raised brown spot

Update on Brown Marmorated Stink Bug on Tree Fruit – August 12, 2011

Friday, August 12th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Please refer to the most recent update from Tracy Leskey, USDA-ARS regarding BMSB activity in tree fruit at: http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2011/08/BMSB-Tree-Fruit-Update-8-8-11-2.pdf.

The photo above, courtesy of Gordon Johnson, is of BMSB damage to peach fruit.

Brown Marmorated Stink Bug Populations This Season

Thursday, July 28th, 2011

Jerry Brust, IPM Vegetable Specialist, University of Maryland; jbrust@umd.edu

Brown marmorated stink bug populations were a big concern early this spring (and also all of last year) as their numbers were found to be pretty high in and around fruit orchards and a few vegetable fields. These were the BMSB that had overwintered that were coming out of their hibernation mode and moving out for something to eat. Their populations grew a bit more in May, but then seemed to hold steady, except for some scattered hot spots throughout the Mid-Atlantic where their numbers and damage were much greater. For the most part, growers were ready for the onslaught and did a good job of limiting the bug’s damage, but at the cost of a heavy spray schedule and the loss of many of their IPM programs. The adult BMSB population has declined over the last few weeks in many areas of the Mid-Atlantic. I am guessing that some of the overwintering adults are dying off and that soon the nymphs will start to be seen in greater numbers than before. This is just what I see happening in some pepper fields. Where before we were finding few adults or egg masses, we now are finding 4-6 nymphs/plant (Photo 1). The nymphs are feeding on both large and very small fruit causing damage that looks much like what the adults would do to peppers (Photo 2). BMSB eggs were looked for earlier in the season and not found to any great extent, but the eggs of any stink bug are very difficult to find. That is why there still are no good thresholds for green and brown stink bugs in many vegetable crops—they are just too difficult to monitor accurately. These medium-size nymphs we are now seeing are easy to spot as they tend to be on the top or edge of the pepper plants in the morning and even during early afternoons. Growers should be looking for the nymphs now in all their vegetables, but especially in peppers and sweet corn even if they have not seen many BMSB adults before this time. These medium to small nymphs while not particularly easy to kill are much easier to control than large nymphs or the adults and this would be the time to control them.

Photo 1. Brown marmorated stink bug nymph

Photo 2. BMSB feeding damage on small and medium size pepper fruit

Section 18 for Brown Marmorated Sting Bug (BMSB) Management on Stone and Pome Fruit Approved

Friday, July 1st, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

This week we received the letter from EPA that they approved our Section 18 request for the use of dinotefuran (Trade Names: Venom from Valent U.S.A. Corporation; Scorpion from Gowan Company, LLC) to control BMSB on stone and pome fruits. This use expires on Oct 15, 2011. Please refer to http://agdev.anr.udel.edu/weeklycropupdate/wp-content/uploads/2011/07/DinotefuranSec18.pdf for more information on use rates and restrictions. Both labels are also available so please contact either David Pyne at the Delaware Department of Agriculture (David.Pyne@state.de.us) or Joanne Whalen (jwhalen@udel.edu) for more information.

 

Update on Brown Marmorated Sting Bug in Fruit

Friday, June 10th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Although we are not able to scout orchards in Delaware, a consultant working with fruit growers in Delaware detected the first damage in peaches and nectarines this week. It appears that the damage is confined to edges near woods; however, they can quickly move into orchards so early detection is important. We do have BLT traps at 3 orchard locations but so far none have been detected in traps. We did find a significant increase in black light trap catches at our Newark farm this past week – but populations were very high in crops on the Newark farm in 2010. It is being shown in other fruit areas that orchard scouting is critical and you should not rely on traps alone for detection. In states where numbers were high last season (WV, Western MD and VA and NJ), they are able to find populations and damage in orchards well before detection in traps this season. Please see the attached “Grower Alert” concerning brown marmorated stink bug that was sent last week by the U.S. Apple Association to US Apple members in the Mid Atlantic region.

 

Update on Brown Marmorated Stink Bugs in Orchards

Friday, May 27th, 2011

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Tracy Leskey (USDA/ARS) provided the following report: “It appears that the beginning of Brown Marmorated Stink Bug (BMSB) immigration and dispersal into commercial orchards has begun in earnest in both WV and MD. Crews out scouting reported large numbers of BMSB in managed peach trees. Not surprisingly, bugs were most dense in the peripheral zone of the plots bordering wild habitat, but not necessarily anywhere near structures. Estimates of bug density were in the vicinity of 3 bugs per tree in border rows, and feeding injury was very fresh but clearly evident.”

See the article titled ‘Brown Marmorated Stink Bugs Damaging Peaches and Apples in WV, NJ, MD and VA’ in WCU 19:9 for more information and photos of damaged fruit.