Spotted Wing Drosophila Update, August 21-29, 2019

This post contains a summary of trap counts for Aug 121-29, 2019.  The numbers reported are number of SWD per trap.

The regional monitoring program is being conducted in berry and stone fruit crops and grapes in Essex, Chatham-Kent, Norfolk, Niagara and Durham counties

The monitoring project is supported by a grant from the Canada Adaptation Program and collaboration among Niagara Peninsula Fruit and Vegetable Growers Association, Ontario Tender Fruit Growers, Eastern Ontario Berry Growers, Grape Growers of Ontario, OMAFRA staff and private consultants.

Traps were first deployed in berry and stone fruit blocks and have now progressed into table and wine grapes.  We have placed 4 traps with commercial SWD lures at each site.  Use these results in addition to your own monitoring program to determine when SWD is present on your farm.  Conduct a salt water test or a plastic baggie test to confirm presence of larvae in fruit.  Click here for instructions on doing this test.

County	Crop	Crop stage	Number of SWD per trap
			Aug 7-14	Aug 14-21	Aug 21-29
Essex	Field raspberry		42F, 38M	54F, 28M	retired
	Peach		89F, 21M	62F, 12M	retired
	Wild		547F, 265M	35F, 31M	retired
	Plum		43F, 18M	76F, 17M	retired
Kent	Blueberry	harvest	15F, 12M	2F, 1M	66F, 89M
	Strawberry	ripe	4F, 16M	1M	3F, 7M
	Raspberry	post harvest	16F, 20M	6F, 7M	72F, 29M
Norfolk	Wild raspberry		15F, 17M	94F, 51M	retired
	Blueberry		67F, 34M	55F, 15M	retired
	Blueberry		36F, 10M	82F, 24M	retired
	Blueberry		34F, 14M	112F, 19M	retired
Niagara	Strawberry	ripe	12F, 5M	12F, 8M	25F, 14M
	Wild	n/a	58F, 18M	10F, 28M	2F, 1M
Niagara	Wild		40F, 23M	retired
	Mulberry		94F, 309M	retired
	Raspberry		63F, 62M	retired
Niagara	Cherry
	Currant	harvest	49F, 65M	25F, 31M	61F, 58M
	Blackberry	ripe	124F, 67M	41F, 8M	72F, 60M
	Raspberry		46F, 83M	retired
Niagara	Apricot	ripe	49F, 15M	37F, 14M	52F, 50M
	Plum	ripe	98F, 25M	26F, 10M	38F, 47M
	Nectarine	ripe	17F, 21M	6F, 2M	26F, 18M
	Peach	ripe	25F, 7M	39F, 9M	10F, 8M
Niagara	Peach	ripe	30F, 84M	13F, 31M	56F, 53M
	Peach	ripe	69F, 217M	17F, 46M	75F, 30M
Niagara	Raspberry		55F, 88M	retired
	Raspberry		18F, 20M	retired
Niagara	nectarine		71F, 49M	retired
	nectarine		16F, 14M	retired
	peach	turning colour	33F, 44M	26F, 21M	28F, 7M
	peach	turning colour	53F, 32M	26F, 24M	40F, 34M
Niagara	nectarine	harvest	5F, 4M	3F, 6M	12F, 28M
	peach	ripe	2F, 2M	2F, 6M	13F, 16M
	peach		18F, 18M	5F, 7M	retired
	apricot		12F, 32M	retired
	table grape	ripe			24F, 17M
	wine grape	veraison			6F, 7M
Niagara	wild	n/a			18F, 29M
	wine grape	veraison			4F, 14M
	wine grape	veraison			25F, 24M
	wine grape	veraison			14F, 12M
	table grape	ripe			40F, 38M
	wine grape	veraison			18F, 22M
Durham	wild		7F, 26M	48F, 143 M	retired
	Blueberry		21F, 13M	86F, 52M	retired
	Blueberry		8F, 3M	58F, 64M	retired
	Blueberry		18F, 10M	19F, 12M	retired

Once sustained catch occurs (two weeks in a row with SWD) growers with ripening crops susceptible to SWD in that region should consider using a product with activity against SWD in preharvest sprays.

SWD may have an impact on sour rot development as it can carry the bacteria and yeasts responsible for the disease (as can the everyday run-of-the-mill Drosophila species).  Therefore it is recommended that once fruit is over 12 Brix, any product selected for managing preharvest grape berry moth should also have activity against SWD.  This topic was covered in a previous blog post:  https://onfruit.ca/2018/09/11/spotted-wing-drosophila-swd-a-problem-for-ontario-grapes/

Check the SWD product registrations on our website.

We are currently testing susceptibility of peach varieties to damage by SWD.  Fruit collected at pre-commercial ripeness, commercial ripeness and tree ripe are being exposed to SWD under lab conditions.  Fruit firmness is measured to classify into the 3 ripeness classes.  Fruit are exposed to SWD for 24 hours and then incubated to allow any SWD to mature to adults.  This will be continued into peaches and grapes.  According to David Jones, MSU extension expert, “For plums and peaches, you shouldn’t be starting management the moment that color creeps in,” he said. “If you initiate a spray program around 4 to 5 pounds of firmness, you should be able to catch them.”  Source:  https://www.goodfruit.com/new-mindset-for-managing-spotted-wing-depredation/  Our preliminary trial on apricot last year supported this observation.

 

This project was funded in part through the Canadian Agricultural Partnership (the Partnership), a federal-provincial-territorial initiative. The Agricultural Adaptation Council assists in the delivery of the Partnership in Ontario.