Baute Bug Blog

Author:  Hannah Fraser, Entomology Program Lead (Hort), OMAFRA

The brown marmorated stink bug (BMSB) is an invasive alien species native to China, South Korea, Taiwan and Japan. It was introduced to North America in the mid 1990s, and was first detected in Allentown, Pennsylvania in 2001. While BMSB is capable of natural spread, the pest is also an excellent hitchhiker and can be moved over large distances in cargo and vehicles. At present it has been found in at least 35 states, though many of these are simply detections rather than confirmed as established in the field.

BMSB has a very broad host range that includes tree fruit, berries, grapes, vegetables, agronomic crops, ornamental trees and ornamental shrubs. Damage results when nymphs and adults feed on either vegetative or fruiting plant parts. The pest is highly mobile and can readily switch hosts, moving between crops throughout the growing season. In 2010 and 2011, BMSB was seen in extremely high numbers in the mid-Atlantic region of the US, where growers reported significant economic loss in multiple crops (particularly tree fruit).

Adults overwinter in sheltered areas that may include homes and other heated buildings. As they can aggregate in very large numbers, the BMSB has become a considerable nuisance pest for home owners where established. While the bugs do not bite humans, they will release a foul smell when handled or otherwise disturbed. They do not lay eggs or reproduce inside structures. Aggregation in artificial structures is not common among stink bugs, and is a behaviour that may provide an early warning of where BMSB has become established.

Earlier this year, we reported on a homeowner find of BMSB in an urban centre in Ontario. In the fall of 2011, there were four additional homeowner interceptions, including two in early December. We have also learned of two confirmed finds in late 2010. All of the finds – a total of seven adult specimens – have occurred in Hamilton, ON. While we have yet to find BMSB in the field, the presence of several specimens in a small geographic area and over multiple years implies that a population of this pest may have already become established in Ontario. At the very least, these interceptions provide important information on where to target surveys in 2012.

How can you help?

BMSB was identified by numerous commodity groups as a pest of significance during the 2011 Canadian Minor Use Pesticide Priority Setting Conference. OMAFRA and other provincial agricultural ministries, Agriculture and Agri-Food Canada, Pest Management Centre and United States counterparts (U.S. IR-4 minor use program) are working together to find pest management solutions for BMSB, in anticipation that this pest could become an agricultural nuisance following its establishment.

If BMSB has become established in Ontario, early detection is important to the long term success of management programs. There is a monitoring network for this pest; however, we have a better chance of finding pockets of small populations if more people are looking. Tracking the distribution and spread is essential. If you think you have found BMSB, contact the Agriculture Information Contact Centre at 1-877-424-1300 or email ag.info.omafra@ontario.ca.  Place the insect in a leak proof container and add rubbing alcohol, or freeze to kill it.

For more information and for updates on BMSB, visit our website at http://www.omafra.gov.on.ca/english/crops/insects/bmsb-resources.html

Authors:

Cara McCreary, OMAFRA

Jocelyn Smith, University of Guelph Ridgetown Campus

The Canadian Corn Refuge Hybrid Selector is a web-based tool that has been developed through collaboration of the Canadian Corn Pest Coalition, the Ontario CornCommittee, and the Canadian Seed Trade Association to provide all the information needed to follow up-to-date insect resistance management (IRM) requirements for all currently available Bt corn hybrids in Ontario.

Simply select the Bt hybrid or trait being planted and the field size and the Refuge Selector will provide a list of eligible refuge hybrids, the refuge size, placement and treatment options along with herbicide tolerance information.  The Refuge Selector can be accessed through the Canadian Corn Pest Coalition website http://www.cornpest.ca/ or through http://www.refugeselector.ca/.  It’s an excellent tool to help you place your 2012 seed order.

Some of you may have noticed this summer that I am expecting a baby.  Starting at the end of October I will be off for a year on maternity leave.  But don’t worry…we haven’t left you guys stranded.  The pests are not going to get the chance to take over while I am away.  We made sure to have someone in place during my leave.  Cara McCreary will be the Acting Field Crop Entomologist with OMAFRA for the next year.   We worked side by side over the last few weeks so she was able to catch up to speed on all of the projects and extension activities I am involved in.

A little bit about Cara: She is currently completing her thesis on the bean leaf beetle in soybeans for a Master of Science in Environmental Biology degree at the University of Guelph.   She has a Bachelor of Commerce degree from University of Windsor and an Associate diploma in Horticulture from University of Guelph, Ridgetown Campus.  Before joining OMAFRA, Cara ran her own business and was involved with several agricultural research projects through the University of Guelph, including the Soybean Breeding Program and the Soybean Aphid Project.

Cara will continue this blog in my absense so no need to stop visiting the blog over the next year.  There are always pest issues to talk about.  And she might even line up some guest bloggers..i.e. top field crop entomologists from both sides of the border to discuss insect topics that they are experts in.  You can reach Cara through this blog, by phone at my office and cell numbers or you can email her at cara.mccreary@ontario.ca.

I am sure you all will make her feel welcome and keep her on her toes with all of your insect issues over the next year.  I know I am leaving you guys in good hands.

I wish you all a great harvest season and I will see you in a year from now.

Tracey

Some corn fields may be at risk of extended WBC feeding this fall, particularly those that were late planted or are situated where egg laying occurred over a wider window.  This year in particular, we are seeing a wide range of larval sizes because of the extended egg laying period that took place across much of the province.  Fields that are maturing quickly may be less at risk, as the larvae will be dropping down to the ground to overwinter as the ears dry down in these fields.

Though we know there were hot spots this year, including Bothwell to Strathroy and south of Tillsonburg, we encourage all corn producers to be scouting for ear damage over the next month.  Scouting will identify additional areas that had decent WBC pressure and are at risk of higher overwintering populations and therefore infestations again next year.  Scouting will also help in deciding whether to harvest the crop earlier, or to segregate grain from those fields to reduce risk of ear rot and vomitoxins.

Fields in the Bothwell area are seeing significant ear damage already.  Even fields planted to Herculex or SmartStax Bt corn that contain Cry1F are seeing greater amounts of damage than growers were expecting.  These Bt hybrids provide only approximately 70 to 80% control, so under heavier pressure, the damage can be significant.

Focus on later planted fields first.  Scout random areas of each field.  Look at 10 consecutive ears in a row.  You might see frass at the ear tip or a hole along the side of the husk where the larva entered. Peel back the husk and determine if larvae are present and make note of how extensive the feeding damage is.  Birds diving into fields is also a good indication that WBC is present and unfortunately they will also contribute to the ear damage.  Once the larvae reach the 6th and last instar, they drop to the soil and tunnel down deep to overwinter there.  If larvae are nowhere to be found in the field, it is a good indication that they have already started to get ready to overwinter.

Hopefully we experience a warm and reasonably dry fall to help mature the crop quickly and avoid ideal weather conditions that promote further ear rot development.

It’s time to get out and scout for WBC damage in dry beans.  Based on trap counts we are now confident that some counties experienced peak flight the last week of July and others the first week of August.  Though I will admit that some trap sites are still catching lots of moths, especially the bean trap sites.  And the storm fronts that have pushed across the province over the last week have also been delivering some moths from Michigan.  One of our Grand Bend traps caught over 400 moths early this week, thanks to the same storm system that also hit Goderich.

In dry beans, scouting 10 to 21 days after peak flight is the ideal time to determine if control is necessary.  Scout a field for 15 to 30 mins.  Select random plants in the field and take a good look at all of the pods on the plant.  If you can easily find pods with holes in them during that time, you need to spray.  If there is just surface feeding or scars on the pod, it may not be WBC damage. It could be from bean leaf beetles.  The only way to know for sure if it is western bean cutworm damage is if there are holes mining directly into the cavity of the pod.  Seed inside will also be fed on.  Open up the pod and see if anything is in there.  If you find a larvae, it is most likely European corn borer.  If nothing is in the pod, it is probably safe to blame the damage on WBC.  WBC larvae only feed at night in dry beans.  They drop out of the pods before sunrise and hang out in the soil or under crop debris during the day.  If in the time that you scout you are only finding a couple of pods with holes, it is not enough damage to warrant a spray.  But check again in another week to see if things have changed.  Matador and Coragen are both registered for dry beans.  Matador has a preharvest interval of 21 days.  Coragen has a preharvest interval of 1 day.

Pod feeding damage by WBC - Note the hole going into the pod

Surface feeding could be from other insects like bean leaf beetle

If a larva is present inside the pod during the day, it is more likely to be European corn borer