Integrated Pest Management

B.C. Pest Monitor — Former Newsletter of IPM in British Columbia

Vol. 6 No. 1 May 1998

New Ways to Manage European Wireworms

Bob Vernon, Ph.D., Agriculture and Agri-Foods Canada
PARC, Agassiz. V0M 1A0

European wireworms, notably Agriotes obscurus and Agriotes lineatus, are gradually spreading in Canada. In the Lower Mainland, these species are the most important insect pests of many crops in the Fraser Valley. They cause serious damage to potatoes, corn, ornamental crops and small fruit, such as strawberries. Since 1990, potato crops have sustained heavy damage resulting in heavy losses in some years. For example, the Delta and Surrey areas alone suffered $500,000 to $800,000 in crop losses in 1994. Wireworm populations appear to be increasing each year and pose a serious threat to B.C. farming sustainability.

Wireworms are the larval stage of click beetles. They live in the soil for 3 to 6 years, depending on the species, where they feed on plant roots and other organic material (we have even seen them feeding on dead birds!). Their favourite habitat is grassland or pasture, where populations can build up to enormous levels over time. When pasture is replaced with another crop such as potato, the wireworms left behind in the soil can cause severe damage for several years.

Procedures for managing wireworms in plantings of strawberries and potatoes are non-existent in B.C. since all previously registered granular insecticides for wireworm control have been withdrawn from use. Few new effective insecticides are expected to be registered for wireworm control, therefore alternative control strategies must be developed. To address this concern, a research program was initiated at the Pacific Agri-Food Research Centre, in Agassiz in 1996.

Potential for Using Trap Crops

Several species of wireworms are known to move through the soil toward pieces of plant roots or germinating wheat; studies have also found that wireworms could follow a CO2 gradient for distances up to 20 cm. Since wheat is a preferred host of the two wireworm species, and CO2 is produced by germinating wheat, we wanted to find out whether freshly sown wheat could act as an effective trap crop.

Our studies were conducted in a farmer´s field in Agassiz, B.C. that had been in pasture for over 10 years. It had been plowed the previous year and had very high numbers of wireworms (A. obscurus).

First, we studied how wireworms move in the soil, both with and without a trap crop present. Our studies confirmed that wireworm populations are near the surface of the soil in April and May, but move further down later in the summer. In the spring, the majority of wireworms were actually within the top 8 cm (3 inches) of soil. This means that we would expect trap crops to be more successful at attracting wireworms in the spring months than in the summer or fall.

We also studied how wireworms move horizontally in the soil using plots with rows of wheat, seeded 1 meter apart. These were compared to control plots without any vegetation. The results showed that the number of wireworms found in the wheat rows was significantly higher than in the bare soil regions in between the wheat rows during the first 3 sampling periods in the early spring. We estimated that on May 23, from 68% to 80% of the resident wireworms in the soil had moved to the wheat rows. The rest of the population would have been in between the wheat rows, or further down in the soil. The number of wireworms in the samples declined steadily after this date, probably because they were beginning to move deeper into the soil by this time. The results of these studies showed that rows of wheat, planted one meter apart, will attract wireworms from unplanted areas at least half a meter away.

To find out how much wheat seed should be sown in the rows we also looked at rate of seeding in relation to wireworm attraction. One week after planting, the number of wireworms aggregated at the untreated wheat rows increased as the density of the wheat increased. Doubling the seeding rate about doubled the number of wireworms caught. Two weeks after seeding, however, there was no significant difference between rows, probably because most of the wheat in the untreated rows had been killed by wireworms by that time.

Our next step was to determine if wireworms aggregating in the wheat rows could be killed there using wheat seed treated with insecticide (i.e., Agrox DL plus or Vitavax Dual). In the treated wheat after 1 week, the number of wireworms aggregated at the wheat rows also increased with the density of the wheat planted. The main difference, however, was in the ratio of dead to living wireworms in these treatments. At the highest seeding rate there were more dead than living wireworms.

Conclusions From These Studies:

1. In early spring, between April and May, the majority of wireworms in soil are near the surface, and it is at that time that trap crops would be most effective. Trap crops planted after May and as winter crops in the fall would likely not be as effective.
2. In properly fallowed fields, most wireworms in the spring can be lured to trap crops such as wheat. The number of wireworms attracted increases proportionally with increased number of wheat seeds per foot of row. From the 1996 studies, an optimal seeding density for a lethal trap crop of wheat will be about 4 treated seeds per inch, with adjacent rows being about one half meter apart.
3. Finally, the results indicate that once wireworms have aggregated to a trap crop, they can be killed by insecticides used as a seed treatment. It appears as though lethal trap crops might be a less expensive and possibly more effective method of reducing wireworm populations.

Practical Applications

Given the results of the studies described above, we have worked out how trap crops could be used in agricultural systems. Trap crops of wheat, for example, could be planted in advance of other susceptible crops such as strawberries. The earlier planted wheat rows would theoretically aggregate the wireworms and keep them away from later planted crops. We have shown this is feasible by planting wheat 1 week before we set out strawberries between the rows of wheat. Wireworm populations aggregated at the wheat rows and did not harm the strawberries. Unprotected strawberries, on the other hand, sustained severe wireworm damage.

For field crops, such as potatoes, we are in the process of studying the following procedure to significantly reduce wireworm populations in a field before planting:

1. The field to be planted should be fallowed over winter to ensure that wireworms would not be distracted by other food sources in the spring.
2. The lethal wheat crop (i.e., seed treated with insecticide) would be planted into fallow ground at least 10 days before the potatoes were planted. The wheat would then be destroyed. If this can be done on more than one consecutive occasion prior to planting, wireworm control would likely be improved.
   

Environmental Impact of Wireworm Pesticides

Before 1970, the use of organochlorine (OC) insecticides such as aldrin, heptachlor and chlordane was common. A single applications of heptachlor to soil could control wireworms for more than 10 years. Unfortunately, many OCs were also quite persistent in the environment, deleterious to certain wildlife species, and as a result were eventually withdrawn from use. They were replaced in the 1970s by other classes of insecticides, such as the carbamates (i.e. carbofuran; aldicarb) and organophosphates (i.e., phorate, terbufos and fonofos), which were shorter lived, but more toxic than the OCs.

In recent years, the use of some of these insecticides has been linked to mortalities in wild duck and geese populations as well as eagles and hawks, especially in the Delta region. It is thought that the problem originates with the use of certain granular materials in the soil for control of wireworms and other insect pests of potatoes. It is hypothesized that a) granular materials become exposed on the soil surface when potato rows are opened at harvest, b) that ducks eat the exposed granules later in the autumn when flooding occurs in the fields, c) that they become sick and die in the field, and d) that eagles and other raptors eat the crop contents of the dead birds and in turn become sick or die. One OP product, phorate (Thimet) was associated with several eagle mortalities in 1993 and 1994, and as a result was withdrawn from use in B.C. by the parent company. In a study presently underway by Agriculture and Agri-Food Canada and the Canadian Wildlife Service, it has been determined that insecticide residues do, in fact, persist on the granular carriers of some insecticides long enough in certain types of soil to pose a threat to wildlife. In another study in 1996, it was determined that granular insecticides applied in-furrow at planting can be brought to the surface at harvest where they would be exposed.

Survey of Pesticide Use in British Columbia: 1995

In 1992, MELP commissioned the first survey of pesticide sales and use records in B.C., using data from 1991.

A second, somewhat more limited, survey was commissioned in 1996 to document pesticide use in 1995 and to make limited comparisons with the 1991 results.

The study results showed that in 1995, British Columbians purchased or used 8,674,920 kg of pesticide active ingredients. This excludes most Domestic label products, but does include Domestic products sold by veterinarians. Of this total, 7,687,656 kg (88.6%) were anti-microbials, consisting primarily of commercially-applied wood preservatives and anti-sapstain chemicals. Insecticides accounted for 354,212 kg (4.1%) of the total pesticides, herbicides accounted for 327,722 kg (3.8%) and 232,490 kg (2.7%) were fungicides. The remaining pesticides included fumigants, plant growth regulators, vertebrate control products, adjuvants and surfactants.

The total, province wide pesticide use included 254 active ingredients. Twenty of these active ingredients accounted for 95.5% of the pesticides sold or used during 1995. Creosote alone accounted for 67.7% of the pesticide use in the province.

The 1995 survey provided the first opportunity to compare pesticide sales and use with the 1991 data. Although a limited comparison was made, the analysis should be viewed with caution as two data points are insufficient to suggest a trend and pesticide sales can vary significantly from year to year in the absence of any overall changes in use patterns.

The following are some of the findings of the 1991 and 1995 data comparisons:

• Of the active ingredients that are not wood treatments or slimicides, 5 were among the top 6 sold in both 1991 and 1995. These were: insecticidal mineral oil, glyphosate, mancozeb, captan and sulphur.
• The total sales of pesticides classified as Restricted were lower in 1995 than in 1991.
• The use of wood preservatives increased in 1995 compared with 1991, primarily as a result of an increase in creosote use (industry reports that such a five-fold change from year to year is not unusual).
• The top 6 active ingredients used by landscape gardening services in the Lower Mainland in both years were insecticidal mineral oil, and the herbicides sodium metaborate tetrahydrate, 2,4-D amine salts, mecoprop, glyphosate and sodium chlorate.
  
  Complete copies of the report are available upon request from:
  Environmental Management Branch
  Ministry of Environment, Lands and Parks
  PO Box 9342 Stn Prov Govt
  Victoria, BC V8W 9M1
  Fax: (250) 387-9935
  
  Or read the full text of the report on-line.

Changes to Provincial Pesticide Control Act
Promote Integrated Pest Management

The Pesticide Control Act of British Columbia was amended as part of the Environment, Lands and Parks Statutes Amendment Act, 1997, which became law on July 28. The biggest changes to the Act, from the point of view of promoting IPM, were the inclusion of a definition of IPM and a provision that enables the ministry to require approved Pest Management Plans (also defined in the Act) in place of pesticide use permits.

Key Changes

The amendments included changes involving:

• definitions
• Pest Management Plans
• seizure, prevention orders, and suspension and revocation of permits, certificates, licenses
• appeals of decisions of the administrator of the Act, and powers to make regulations

Definitions

Several minor changes to existing definitions were accompanied by the inclusion of the following new definitions:

1. "Integrated Pest Management" means a decision making process that uses a combination of techniques to suppress pests and that must include but is not limited to the following elements:
   (a) planning and managing ecosystems to prevent organisms from becoming pests;
   (b) identifying potential pest problems;
   (c) monitoring populations of pests and beneficial organisms, pest damage and environmental conditions:
   (d) using injury thresholds in making treatment decisions:
   (e) reducing pest populations to acceptable levels using strategies that may include a combination of biological, physical, cultural, mechanical, behavioural and chemical controls;
   (f) evaluating the effectiveness of treatments.
   
   
2. "Pest Management Plan" means a plan that describes
   (a) a program for controlling pests or reducing pest damage using integrated pest management, and
   (b) the methods of handling, preparing, mixing, applying and otherwise using pesticides within the program.
   

Provisions for Permits and Pest Management Plans

Section 6 of the Act has been augmented by including provisions for Pest Management Plans to replace Pesticide Use Permits. Approved Pest Management Plans will authorize pesticide use within the decision-making framework of an Integrated Pest Management Program. They will cover a wider geographic area than permits and will be valid for a longer time span. Most permits are anticipated to be replaced by Pest Management Plans within a few years.

Seizure and Prevention, Suspension and Revocation

A number of functions have been extended to accommodate the new provision for Pest Management Plans. These include the ability for:

• inspectors to seize material that is the subject of a contravention of an approved Pest Management Plan and to serve notice of an order to prevent or stop further contravention; and
• the administrator may suspend, amend, revoke, or refuse to approve a Pest Management Plan.

Appeals to the Environmental Appeal Board

Section 14 of the Act defined a "Pesticide Control Appeal Board," but appeals under the Act were actually heard by the Environmental Appeal Board which is authorized under the Environment Management Act. This section was therefore redundant and was deleted.

Provisions in section 15 have been replaced to establish that the Environmental Appeal Board is the tribunal for hearing appeals under the Act, consistent with amendments to the Waste Management Act, Water Act, and Wildlife Act.

Regulation Making Authority

Section 24 has been amended to expand the authority to make regulations under the Act, for items such as:

• Pest Management Plans
• standards for persons training others in the application of pesticides
• standards for monitoring of pesticides
• criteria and content for licences, certificates, permits and Pest Management Plans
• fees for assessments, and
• delegating authority to the administrator of the Act
  

Publications

Integrated Pest Management Manual for Structural Pests in British Columbia.
1996. L. A. Gilkeson and R. W. Adams

This manual from BC Environment was prepared to train structural pest control operators in British Columbia to use an IPM approach in their work; it could also help potential clients to know what to look for when they hire pest services. The manual describes the basic principles of IPM as they apply to structural pests and gives examples of IPM programs for pests such as ants, cockroaches, fleas, stored products pests, silverfish and firebrats, rodents, termites, powderpost beetles and birds. The emphasis is on prevention of pest problems and use of non-chemical controls. There is a chapter devoted to preferred pesticides, such as borates, sorptive dusts, botanicals and insect growth regulators. Other commonly used pesticides in the structural industry are also covered, along with specific precautions for using them. 108 pp.

Available from:
Office Products Centre
4248 Glanford Ave.
Victoria BC V8Z 4B8
Phone: 1-800-282-7955
Fax: (250) 952-4442

Cost CDN $15.00 + shipping and handling

Or read the entire manual on-line at the IPMP web site.

Greening Your BC Golf Course: A Guide to Environmental Management
1996. Fraser River Action Plan

This newly released guide contains a wealth of information on designing and managing an "eco-friendly" golf course under BC conditions. The recommendations arise from an extensive study of golf course management practices in BC, including detailed site assessments and water and soil sampling. References and a bibliography are included to assist readers to find more information. 50 pgs.

Available at no charge from:
Fraser River Action Plan
Communications Officer
Environment Canada
700 - 1200 West 73rd Avenue
Vancouver, B.C.
V6P 6H9
fax: 604- 664-4068 phone: 604-664-9198

Pest Management At the Crossroads.
1996. Charles M. Benbrook

This is an excellent, comprehensive look at the history of pesticide use and at integrated pest management, published by the Consumer´s Union in the US. Lead researcher, Dr. Charles M. Benbrook and his team have defined a program to reduce public health and environmental risks from pesticides at least 75 percent by the year 2020. This includes speeding the conversion from the current reliance on chemical pesticides to methods that keep pests in check with preventive tactics and biological controls. The continuum of IPM is well presented, along with what needs to be done to move from "Low" (or chemically dependent) IPM to "High" (also called "biointensive") IPM, which relies on reduced-risk pesticides only when other, non-chemical measures fall short. The book documents the many successful IPM programs already in place in agriculture, landscapes, and government agencies. Includes references and an extensive directory of computer databases devoted to IPM.
288 pgs.

Available from:
Pest Management at the Crossroads
P.O. Box 2013
Annapolis Junction, Md. 20701
Phone: 301-617-7815
Fax: 301-206-9789
e-mail: pmac@pmds.com

Cost: US $38.95 (includes shipping and handling)

Or order directly through the PMAC web site: http://www.pmac.net/ This web site contains far more than the book information; it is an excellent reference site for new IPM information, current initiatives and IPM related web sites.

Safe and Sensible Pest Control.
1992-1996. By L. Gilkeson
This is a series of brochures developed by BC Environment to encourage the use of safe, practical alternatives to the overuse of pesticide against common pests of home and garden. A new title in the series, Indoor Plant Pests, describes common pests in houseplants and hobby greenhouses and gives least-toxic controls, including how to use biological controls for these pests.

Other titles available:
Aphids, Beneficial Insects, Carpenter Ants, Caterpillars, Fleas, Household Pests, Rats and Mice, Turf Weeds, Yellowjackets, Bats

Available from:
IPM Unit
Environmental Management Branch
Ministry of Environment, Lands and Parks
PO Box 9342 Stn Prov Govt
Victoria, BC V8W 9M1
Fax: 250-387-9935


Or read any of these brochures on-line at Brochures.

Ministry Moves to Jutland Road

Most of the staff of the Ministry of Environment, Lands and Parks moved in September to a new building at 2975 Jutland Road, on the Gorge waterway. Employee phone numbers have generally remained the same, however, the mailing addresses as well as some fax numbers have changed.
[Note: Ministry E-mail addresses are also expected to change early this year].

The new mailing address for BC Pest Monitor is:
Environmental Management Branch
Ministry of Environment
PO Box 9342 Stn Prov Govt
Victoria, BC V8W 9M1

Fax: 250-387-9935

IPM Training for Structural Pesticide Applicators

As of September 1997, the pesticide applicator certification training for the structural category was changed over to new course materials that emphasizes training in IPM. The study kit now includes the new manual "Integrated Pest Management Manual for Structural Pests in British Columbia" as well as an updated study guide and exam. The name of the applicator certificates based on the new exam has been changed to "Structural - Integrated Pest Management Certificates" to reflect the new training.

All currently certified applicators must write the new exam when their present certificate expires. It is hoped, however, that all structural pest managers will study the new manual and obtain an IPM certificate as soon as possible, whether or not their current certificate is about to expire.

Once an applicator has achieved an IPM certificate, they will be eligible to obtain re-certification in the future by obtaining credits for attending training seminars and workshops. This credit initiative is currently being coordinated by the Urban Pest Management Association of BC (for information, contact: Ross Bird, President of the UPMA, 604-460-2000).

For ordering information on certification study kits, including the new IPM manual for structural pests, contact: Office Products Centre, 4248 Glanford Ave. Victoria BC V8Z 4B8 Tel: 1-800-282-7955 Fax: 250- 952-4442
(Also, see the Publications section of this newsletter).

Pest Management Plans in the Works for Forestry

With financial assistance this year from the Forest Renewal BC fund, Ministry of Environment, Lands and Parks staff in Victoria, Prince George and Namaimo are working on introducing Pest Management Plans to replace Pesticide Use Permits in the forestry sector. The principal objective of this proposal is to ensure that pesticides are only used in the context of an IPM program, with full consideration and use of alternative pest management techniques. Benefits of IPM include reduced production costs, opportunities for local employment, and enhanced environmental protection.

This year the project is focusing on:

• developing content and standards for Pest Management Plans, consultation and environmental protection
• revising and producing new applicator certification training materials for the forestry sector
• designing a computerized system for administering the PMP program

Printed copies of back issues of BC Pest Monitor are still available from:
Environmental Management Branch, PO Box 9342, Stn Prov Govt, Victoria BC V8W 9M1, Fax: (250) 387-9935.

May 1992 Vol. 1(1):

• Integrated Pest Management in B.C.
• IPM in Vancouver Parks
• District of Coquitlam's Vegetation Management Plan

Nov. 1992 Vol. 1(2):

• Using Sheep for Vegetation Management in B.C.
• CP Rail System Vegetation Steam Car

May 1993 Vol 2(1):

• Developing an IPM on Pears in B.C.
• Apple Pest Management in B.C.

Nov. 1993 Vol 2(2):

• Tree and Ornamental Disease Control in the City of Victoria
• Turf Disease Control Through Integrated Turf Management
• Pest Management Plans in B.C.

May 1994 Vol. 3(1):

• IPM for Structural Pests
• IPM for Cockroaches

Nov. 1994 Vol. 3(2):

• IPM Programs in B.C. Cranberries
• IPM in B.C. Blueberries

June 1995 Vol. 4(1)

• Garry Oak Pest Update
• Biological Control of Aphids in Vancouver
• Ladybugs
• IPM in Agriculture

Dec. 1995 Vol. 4(2):

• Preventing Deer Damage
• Living with Raccoons
• Bats

June 1996 Vol. 5(1):

• Ecological Vegetation Management
• Treatment Thresholds for Landscape Pests