Category Archives: Legume Vegetables

Pest of the Month – Bean Leaf Beetle

From ONvegetables in The Grower, December 2014

Scientific Name: Certoma trifurcata

Identification
Bean leaf beetle adults are 5 mm in length with four black spots on the wing covers. A small, black triangle is visible at the base of the head (Figure 1, adult bean leaf beetle). The colour varies from yellow-to-tan or red. The black spots are not always apparent. Bean leaf beetle larvae complete their development in the soil, feeding on roots. The margins of the wing cover have a black border.

Damage starts as large holes in the leaves (Figure 2, bean leaf beetle feeding damage). As feeding continues, they consume the entire leaf expect for the veins, leaving a skeletonized appearance. Bean leaf beetle adults feed on leaves, blossoms and pods.

bean leaf beetle adult
Figure 1. Adult Bean Leaf Beetle
bean leaf beetle feeding injury
Figure 2. Bean Leaf Beetle Feeding Damage

Biology
Bean leaf beetles over-winter as adults in grassy fencerows, leaf litter and wooded areas. They emerge in late-April and may be found feeding in alfalfa fields. Early snap bean fields planted close to alfalfa are at the greatest risk of bean leaf beetle damage.

The over-wintering female beetles lay clusters of lemon-shaped, bright orange eggs at the base of the bean plant. Egg-laying continues until late June. Larvae feed on roots and soil debris for approximately 30 days prior to pupating. First generation adults emerge in mid-to-late-July. This generation lives for approximately 1 month. A second generation of adults emerges mid-to-late August and feeds until it runs out of a food source, either due to harvest activities, crop senescence or cold fall temperatures, and the adults migrate to their over-wintering sites.

Period of Activity
Generational peaks occur from crop emergence to late-June (overwintering), mid-to-late July (first generation) and late-August (second generation).

Scouting Notes
These pests often feed in clusters. Examine 1m of row at each of 10 locations across the field. Select a wide range of field locations, including border areas.

Thresholds
Apply a control if beetles exceed 1 beetle per foot of row or if defoliation exceeds 25%. Defoliation prior to bloom does not have as strong an impact on yield. Early season bean leaf beetle populations may be adequately controlled by systemic insecticide seed treatments used to control potato leafhopper.

Tolerances in snap beans will be significantly lower after pod-set if the beetles are feeding on the pods or where they may become potential contaminants for the processor.

Management Notes
Consider using border sprays to control the beetles as they move out of the fencerow. Consult the Ontario Vegetable Crop Protection Guide (OMAFRA publication 838) for a list of registered foliar and seed treatments.

Bacterial Brown Spot in Snap Beans

Michael Celetti, OMAFRA Plant Pathologist Horticulture Crops Program Lead, Guelph

Elaine Roddy, OMAFRA Vegetable Specialist, Ridgetown

Bacterial brown spot is a serious disease of snap beans particularly some yellow varieties. The disease has caused damage in a few snap bean fields in Ontario this past month. It is caused by bacteria (Pseudomonas syringae pv. syringae) that overwinter in previously infected snap bean debris or on contaminated seed. Once introduced into a field the bacterial pathogen can infect and multiply on emerging volunteer snap bean seedlings. The bacteria have also been found to survive for a period of time on the surface of plants without causing disease symptoms.

Symptoms of bacterial brown spot on snap beans first appear as small water soaked lesions usually observed on the underside of leaves. As the lesions mature, they turn brown and the dead tissue in the center may fall out giving the infected leaf a “shot hole” appearance (Figure 1). Sometimes a small light yellow or pale green border may surround the lesions. The bacteria can also infect pods resulting in brown water soaked spots making them unmarketable (Figure 2).

Continue reading Bacterial Brown Spot in Snap Beans

Integrated Pest Management Workshop Now Available by Webinar

Memo to all Growers, Scouts and Agribusiness:

The Sweet Corn, Bean and Pea Integrated Pest Management Workshop will now also be available by webinar.  If distance or time was preventing you from registering for the workshop, you can now get all the same great information, without the travel!

The workshop and webinar are planned for:

Tuesday, May 20th, 2014
1:00 pm to 3:30 pm

In-person:
Room 102, Rudy Brown Rural Development Centre
Ridgetown Campus, Ridgetown Ontario

Webinar:
The comfort of your own home or office!

Please pre-register for the workshop or the webinar by contacting the Agricultural Information Contact Centre (toll free) at 1-877-424-1300.  Late registrations (after Friday, May 16th) should be directed to elaine.roddy@ontario.ca

Topics covered will include:

  • Scouting and Diagnostics
  • Insects – Identification, Biology and Management
  • Diseases – Identification, Biology and Management
  • Soils and Nutrients
  • Reference Guides and Scouting Materials

Sweet Corn, Bean and Pea Integrated Pest Management Workshop

Tuesday, May 20th, 2014
1:00 pm to 3:30 pm
Room 102, Rudy Brown Rural Development Centre
Ridgetown Campus, Ridgetown Ontario

The workshop will also be broadcast as a webinar, for those unable to travel to Ridgetown.

Please pre-register for the workshop or the webinar by contacting the Agricultural Information Contact Centre (toll free) at 1-877-424-1300.  Late registrations (after Friday, May 16th) should be directed to elaine.roddy@ontario.ca

Topics covered will include:

  • Scouting and Diagnostics
  • Insects – Identification, Biology and Management
  • Diseases – Identification, Biology and Management
  • Soils and Nutrients
  • Reference Guides and Scouting Materials

Pest of the Month – White Mould in Snap Beans

From ONvegetables in The Grower, December 2013

Beans are susceptible to white mould infections during flowering and early pod-set.  Small, circular, water-soaked lesions develop on the pods of infected flowers, or where fallen petals become caught in the lower canopy or leaf axils.

Infected tissues later develop a dense, cottony, white fungal growth.  Leaves of severely infected plants will eventually turn yellow and fall off.  Sclerotia (hard, black, irregular-shaped fruiting bodies) form in the branches, stems and pods of infected plants (Figure 1).

White mould over-winters mycelium in infected crop residue and as buried sclerotia.  The sclerotia will survive for up to five years in soil and crop residue. Continue reading Pest of the Month – White Mould in Snap Beans

Western Bean Cutworm in Sweet Corn and Snap Beans

Increasing trap counts over the past several weeks indicate that the Western Bean Cutworm (WBCW) adults are nearing peak flight. With the early tassling of the field corn crop this year, vegetable crops may be under increased pressure of WBCW feeding. The appropriate approach to controlling WBCW will depend on the crop and the geographic area. Continue reading Western Bean Cutworm in Sweet Corn and Snap Beans

Minor Use Label Expansion Granted For Assail 70 WP Insecticide for Control of Aphids on Succulent Peas and Beans

J. Chaput, OMAFRA, Minor Use Coordinator, Guelph

The Pest Management Regulatory Agency (PMRA) recently announced the approval of a minor use label expansion for ASSAIL 70 WP insecticide (acetamiprid) for control of aphids on succulent shelled peas and beans, crop subgroup 6B in Canada. ASSAIL 70 WP (acetamiprid) was already labeled for management of a variety of insect pests on a range of crops in Canada.

Continue reading Minor Use Label Expansion Granted For Assail 70 WP Insecticide for Control of Aphids on Succulent Peas and Beans