Cucumber beetles are here

Stripped cucumber beetle, illustration by Jessica MacDonald

Striped cucumber beetles have made their annual debut in the Annapolis Valley.  These pests are problematic in many ways.  Feeding damage can stunt plants, and when flowers are predated, it can reduce fruit set and yield.  Cucumber beetles also vector bacterial wilt.  Scarring on fruit by adult beetles reduce the marketability of the crop. 

Newly emerging cucurbit plants are particularly susceptible to stunting and bacterial wilt, while older plants can withstand up to 25% defoliation.  Early season control is essential with this pest, and it is important to scout your fields regularly. 

For more information on cucumber beetle biology, beneficial insects, and organic management, check out Managing Cucumber Beetles in Organic Farming Systems on eXtension.
 
Please click here for Perennia's Pest Management Guides for Cucumbers and for Melons.  For Perennia's Pest Management Guides for Pumpkin and Squash, please click here.  Insect netting can also be an effective control option for this pest, but netting must be removed at flowering for pollination to occur.

Field Day: What's the Deal with Delia?

Join us on a field tour on Thursday, July 9th, 2015 from 8:15 am to noon!  

Come learn more about onion maggots (Delia antigua) and other Delia species that attack onions, corn, beans, and Brassicas such as cabbage, broccoli, cauliflower, radishes, kale and Brussel sprouts.

Figure 1. Onion maggot damage.

AAFC is currently conducting research to determine which Delia species are present in Nova Scotian onion fields and to determine if surrounding vegetation or field history can influence Delia populations and subsequent damage.

Netting and floating row cover can be powerful tools to combat insect pests such as cabbage root maggot (Delia radicum). Perennia and AAFC are currently conducting research into the efficacy of different netting mesh sizes. A Wondermesh Netting/Row Cover Retriever will be on hand to demonstrate technology that makes using netting and row covers easier!

Figure 2. Wondermesh Netting/Row cover Retriever.

Carrot weevils (Listronotus oregonensis) are sporadic pests of carrots. Current AAFC studies are evaluating the carrot weevil’s movement within the field and identifying overwintering sites.

Please call Gail at (902) 678-7722 or visit www.perenniaregistrations.com
to register!

Coffee and muffins at 8:15 AM at the Kentville Research Station - bus leaves at 8:30 AM sharp!

Insect and Floating Row Covers

Insect covers provide an alternative pest control option for growers.  Insect covers come in different sizes and are suitable for control of a whole host of insects such as carrot rust fly, cabbage maggot, and flea beetles.   Insect covers will create a physical barrier between the crop and flying insects.  It has to be applied tightly so insects are unable to get under the netting.

 

Insect cover on rutabaga

 

Insect covers do not trap heat and therefore are used on cole crops, carrots etc where extra heat might be undesirable.  On the other hand crops such as cucurbits, lettuce and peppers may benefit from extra heat, so floating row covers are more beneficial.

 

Floating row cover on lettuce

 

Cucumber Beetle!

Cucumber beetles are the most important insect pests of vine crops or cucurbits (cucumber, squash, melons, and pumpkins) in Atlantic Canada. The striped cucumber and the spotted cucumber beetle occur in the Northeast of US and Canada Not only cucumber beetles can cause losses to cucurbits by direct feeding on young plants, blossoms, and fruit but they also are vector bacterial wilt.

If not controlled cucumber beetles can destroy entire crop. For organic producers row covers can be very effective by creating a physical barrier between crop and insect. However, floating row covers need to be removed at the time when crop begins to flower so that pollinators can get in and do their job. For chemical control, drench with Admire insecticide has been the most effective and in some years may provide season long control.

Growers are advised to monitor crop for cucumber beetle and apply insecticide at the first sing of insect in the field.

For detail information about registered pesticides please visit:
Cucumbers: http://agrapoint.ca/Pest%20Management%20Guides/Vegetables/2012/Cucumber%202012.pdf
Squash: http://agrapoint.ca/Pest%20Management%20Guides/Vegetables/2012/Pumpkin%20and%20Squash%202012.pdf
Melons: http://agrapoint.ca/Pest%20Management%20Guides/Vegetables/2012/Melons%202012.pdf

Cabbage Maggot Control

Cabbage maggot is one of the most destructive pests of cole crops in the Maritimes. The first generation is the most important to control because plants are small and very susceptible to damage.

The best control method consists of preventing the flies from laying eggs. Physical barriers such as row covers or netting of fine screening can be used for this purpose. The research shows that these can be as effective as insecticide application as long as it is placed over the crop immediately after the seeding (rutabaga) or transplanting (cabbage, cauliflower and broccoli).  In order to be effective, there must be no gaps or tears in the material, the material must be placed over the crop before or immediately upon crop emergence or transplanting, and no hosts of the pests should have been grown on that site the previous year. It is also important to bury the edges of the netting so that  cabbage maggot flies cannot get under the edges, and to allow the cover to be a little loose so the plants have room to grow.

Large commercial planting will have to be treated with insecticide for cabbage maggot. For more information please visit: http://www.agrapoint.ca/Pest%20Management%20Guides/Vegetables/2012/Cole%20Crops%202012.pdf

Given that the first generation of cabbage maggot was strong in 2012 it is fair to expect that the second generation which is less severe might be significant.

Rutabaga grown under netting.