History of Gypsy Moth Infestations
in British Columbia

 

Distribution | Detection History | Treatment History | Current Status


Gypsy moth (Lymantria dispar) has been found in British Columbia since 1978 but so far they have not become permanently established due to aggressive monitoring and eradication programs conducted by the Federal and Provincial governments.  The insect is well-established in eastern North America.  The Canadian Food Inspection agency lists infested areas in North America in their directive memo D-98-09 - Appendix 1.  These areas are the potential source of new infestations in B.C. and the western states.

The following history of gypsy moth detection records and treatment efforts is copied by permission from the CFS publication Gypsy moth Pest Leaflet Number 75, Pacific Forestry Centre. The original publication is available through the Canadian Forest Service Bookstore site.  The tables have since been updated to provide the most current status of the gypsy moth trap catches and egg mass finds.  Links to more information on past treatment activities is also included in the last table.

A recent article by Dr. Vince Nealis Still invasive after all these years: Keeping gypsy moth out of British Columbia. 2009. The Forestry Chronicle 85(4): 593-603 provides a more detailed description of the gypsy moth eradication efforts and is available through the CFS Bookstore.

A description of the monitoring (trapping) protocols is also provided on this web site.

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The Distribution of Gypsy Moth

The gypsy moth is a native insect of Europe and North Africa, and it occurs across Asia to Japan. In North America, the European race is established in the north eastern United States and the provinces of Quebec and Ontario, having expanded from the original introduction at Medford, Massachusetts in 1868. During the 1970s and 1980s, it was found in numbers sufficient to cause concern in the western states of California, Utah, Oregon and Washington as well as in British Columbia. These occurrences were caused by the transportation of egg-laden materials from eastern sources. In 1991, federal inspectors found egg masses of the Asian race on Russian ships at Vancouver waiting to load grain; male moths were subsequently trapped on shore. British Columbia therefore now faces the threat of gypsy moth introductions from sources to the east, south and west.

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The Gypsy Moth in British Columbia

The first recorded interception of the gypsy moth in the province occurred in 1911, although unconfirmed interceptions may have been made two to three years earlier. In that year a single egg mass was found on imported European nursery stock by a provincial inspector at Vancouver. About the same time, in Vancouver, more egg masses were found on ornamental Thuja trees from Japan.

The British Columbia Gypsy Moth Detection Story, 1911-2010

1911-1989 > 1990 - 1999 > 2000 - 2009 > 2010 - present

1911 to 1989
YEAR EGG   MASSES ** LARVAE ADULTS TRAPPED NO. OF SITES COMMENTS (bold text indicates areas treated the following year)
1911* 8

Few

 

0

On Thuja (cedar) trees imported from Japan, eggs hatched after interception
1978 40  

5

1

Egg masses found on canoe in Kitsilano
1980    

1

1

Male trapped at Tsawwassen
1981    

1

1

Single male in Kitsilano
1982* Few

Few

10

4

European males in Fraser Valley, Vancouver; Asian egg masses found on vessel at Vancouver, eggs hatched after interception
1983 34  

38

5

Egg masses at Ft. Langley & Courtenay
1984 33

Few

35

5

First trap capture in interior (Adams River); European egg masses at  Chilliwack & Courtenay
1985 3  

17

4

Egg masses at Chilliwack
1986 21  

24

8

Egg masses at Chilliwack & Kelowna
1987 43  

259

6

33 egg masses, 38 females & 27 pupae at Kelowna; 7 egg masses at Colwood; 3 new, 29 old egg masses Parksville
1988  

11

7

   
1989*

81

Few

27

11

One egg mass and a pupa found at Parksville; 80 Asian egg masses found on ship at Victoria.
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1990-1999
YEAR EGG   MASSES ** LARVAE ADULTS TRAPPED NO. OF SITES COMMENTS (bold text indicates areas treated the following year)
1990*

>236

Few

147

16 36 egg masses & 12 females in North Saanich; hundreds of Asian egg masses, some hatching larvae and 15 dead females on vessel.
1991*

>2000

>1000

81

24 Thousands of Asian egg masses on ships, eggs hatching and larvae ballooning in Vancouver harbour; 29 grain ships infested, ban effected; 23 Asian males trapped around port of Vancouver.
1992*

>120

Few

165

33 European egg masses on Salt Spring Island (9), Hope (3), 8 new, 1 old egg mass & 3 females in Richmond; 16 ships banned when Asian egg masses (>100) and some hatching larvae found
1993*

25

 

142

17 European egg masses (19) at Victoria, Hope, Nanaimo, South Vancouver & Whiskey Creek, 2 females at Hope; single Asian males at Victoria & Surrey, 4 egg masses on vessel; 2 egg masses, 1 dead male found associated with military equipment from Germany, possible hybrids.
1994*    

39

8+ European moths captured at 8 separate locations including: Nanaimo (5); Gabriola Is. (2); Burnaby (2) and Victoria (2). Populations present at Hope (8) and Chilliwack(15) epicentres. Asian males recovered in Langley (1); Surrey (3)
1995*    

38

14+ European moths captured at 14 locations including: 2 sites in greater Victoria; Sproat Lake on Vancouver Island; Mission; and 8 locations around greater Vancouver. A new population epicenter was found in New Westminster (12 males). Single Asian moths were captured at two locations in greater Vancouver.
1996

3

 

52

11+ Low numbers of European gypsy moth males captured in the Esquimalt (2) and Langford (8) areas of greater Victoria; 2 moths present in Nanaimo; 27 moths captured at New Westminster epicentre discovered in 1995. Three live and 4 hatched egg masses, 1 pupa and 3 female found at New Westminster site. No Asian males captured anywhere in the province.
1997

82

 

260

14+

Increased numbers of European moth captures at Esquimalt (60) and Langford (147); first captures at Knockan Hill (3) in greater Victoria. First capture of moths in Duncan (6). Egg masses laid in 1997 discovered in association with Langford and Esquimalt populations during searches and 1998 treatment program.

Go to 1997 trapping map

1998 >50 >1 000 585 10+ Moth captures in the Esquimalt, Langford and Knockan Hill areas of greater Victoria increase to total 503 European males; male captures increase in the Duncan (33) and Nanaimo (8) areas. Three males captured in both Richmond and near Tsawwassen (1). Egg masses present at Duncan (12), Nanaimo (1) and Tsawwassen (1). Hatching egg masses and feeding larvae discovered during inspections conducted as part of ground spray efforts in Langford. 

Single male moths were also recovered from Richmond, N. Delta, and, the most northern catch ever recorded in B.C., near Kitwanga in northwestern British Columbia.

Go to 1998 trapping map

1999 15 - 44 9 CFIA located moths in Comox (6), Duncan (1), Victoria (1), the Highlands (2), Burnaby (23), Kelowna (2), Sechelt (5), Chilliwack (1) and North Delta (3). The moths found in Comox, the Highlands, Burnaby, Kelowna, Sechelt, Chilliwack and North Delta were not in the 1999 aerial spray zones.  Egg masses were only located in Burnaby.

Go to 1999 Trapping Maps

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2000-2009
YEAR EGG   MASSES ** LARVAE ADULTS TRAPPED NO. OF SITES COMMENTS (bold text indicates areas treated the following year)
2000 3 - 23   Chilliwack (2), Kelowna (1), Coquitlam (1), Vancouver (1), Oak Bay (1), Sechelt (9), Delta (8)

Go to 2000 Trapping Maps

2001 - 11   Chase (1), Grand Forks (1), Mission (1), Langley (1), Delta (3), Sooke (1), Saanich (1), Victoria (2)
2002 - - 15 7 Courtenay (2), Saanich (2), Colwood (1), Delta (6), Chilliwack (1), Kal Beach (1), Mabel Lk. (2)

Go to 2002 Trapping Map

2003 18 - 100 16 Lower Mainland: Abbotsford (2), Burnaby (2), Chilliwack (1), N. Delta (43, 15 egg masses), Langley (4), N. Vancouver (1), Richmond (1), Vancouver (1)

Vancouver Is.:  Campbell R. (1), Duncan (3), Gabriola Is. (4), Gordon Head (Saanich) (33, 2 egg masses), Nanaimo (1), Oak Bay (1), Sooke (1), View Royal (1)

Go to 2003 Trapping Maps

2004 0 - 89   14 Langley (4), Burnaby (1), Chilliwack (2), Harrison Hot Springs (4), Vancouver (2), Courtenay (1), Nanaimo (5), Gabriola Island (22 mt), Duncan (24 mt), Saltspring Island (7), Sidney (1), Esquimalt (3) and Victoria (Saanich, Oak Bay and Vic West)(12).  No egg masses found.

Go to 2004 Trapping Maps

2005 2 on Salt Spring, 1 in Nanaimo, 1 in Saanich and 1 non-viable (unfertilized) egg mass on Gabriola Is. - 135 22 Maple Ridge (1), Langley (3 mt), Cloverdale (2), Surrey (1), Delta (4), Burnaby (3), Coquitlam (1), Silver Ck. (1), Courtenay (8), Nanaimo (11), Gabriola Is. (19 mt), Saltspring Is. (43), Duncan (2 mt), Sidney (8), Central Saanich (1), Christmas Hill (1), Esquimalt (1), Colwood (1), Saanich (17 mt), Cedar Hill (6), and Oak Bay (1)

Go to 2005 Trapping Maps

2006 4 at Cedar Hill Golf Course(Saanich), 1 non-viable in Sidney, 1 Belmont Park (Colwood) - 153 15 Grand Forks (1), Harrison Lk. (1), Chilliwack (1), White Rock (1), Delta (Annacis Is.)(2), Saanich (3), Courtenay (39), Sidney (22 mt), Colwood (7), Lk Cowichan (1), Mill Bay (1), Ladysmith (6), Nanaimo (1),  Cedar Hill Golf Course (32 mt), Saltspring Island (35 mt)

Go to 2006 Trapping Maps

2007 - - 45 15 Saltspring Island (13 - 10 in mt grid), Saltair (Ladysmith)(10 - 6 mt), Lake Cowichan (5), Shawnigan Lk (1), Prospect Lk (1), Delta (2), Burnaby (1), White Rock (1), Harrison Hot Springs (6), Langley (5)

Go to 2007 Trapping Maps

2008 100 - 33 17 Chilliwack (1), Harrison Hot Springs (16), Richmond (2), S. Surrey/White Rock (3), Delta (3), Langley (2), Vancouver (2), Burnaby (1), Victoria (2), Creston (1)

Go to 2008 Trapping Maps

2009 7 - 30 24 Richmond (10), North Vancouver (2), Harrison (5), White Rock (5), Vancouver (1), Abbotsford (2), Langley (1), Duncan (1), Comox (1), Chemainus (1), Shawnigan Lake (1)

Go to 2009 Trapping Maps
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2010 to present
YEAR EGG   MASSES ** LARVAE ADULTS TRAPPED NO. OF SITES COMMENTS (bold text indicates areas treated the following year)
2010 0 - 12 9 Harrison (1), Port Moody (1), North Vancouver (2), Comox (4), Nelson (2), Revelstoke (2)

Go to 2010 Trapping Maps
2011 0 - 6 6 Revelstoke (1), Victoria (2), Richmond (1), Surrey (1), Chilliwack (1)
Go to 2011 Trapping Maps
2012 0 - 3 3 Kaslo (1), Sooke (1), Delta (1)
Go to 2012 Trapping Maps
2013 0 - 13 12 Shawnigan Lk (4), Surrey (3), Richmond (1), New Westminster (1) , Langley (3),  McLeese Lk (1)
Go to 2013 Trapping Maps
2014 10+ 10+ 214 28 Surrey(197), Delta (7), Aldergrove (1), Golden Ears Park (1), N. Surrey (4), Saanich (1), Colwood (1), Comox (1), Trail (1)

* Denotes years in which gypsy moths of Asian origin were detected (see Comments).
** Does not include old (emerged) egg masses.
mt = mass trapping at 9 traps per acre = 5,760 traps/sq.mi.
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The Gypsy Moth Threat to British Columbia

During the past thirty years, an assertive program to prevent permanent establishment of the gypsy moth in the southern part of the province has been successful. The program, based on comprehensive surveys and spray treatments using the biological insecticide Btk (Bacillus thuringiensis var. kurstaki), has been coordinated through the B.C. Gypsy Moth Committee of the Plant Protection Advisory Council of British Columbia. The primary challenge of the program is to deal with repeated introductions of the pest.

To date, treatment programs have been conducted at the following locations.  The majority of these treatments have been highly successful.  More detailed descriptions of the different treatment methods are provided and selection process are provided on the Gypsy Moth Management page.

Alternative treatments*  (non-spray), have been used with limited or inconclusive results.  The Ministry of Forests and Range continues to test non-spray treatments to determine their effectiveness as eradication methods and define the optimal conditions for their deployment.  Preventative measures are exercised by the Federal government's Canadian Food Inspection Agency (CFIA) who restrict movement of goods that may be infested by gypsy moth by imposing a regulated area over the known infestation.

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TREATMENT HISTORY

(Btk was used for all treatments unless otherwise noted)

Location Year of Detection Year of Treatment
Kitsilano* 1978 1979
Ft. Langley 1982 1984
Courtenay 1983 1984-85
CFB Chilliwack 1983 1985, 86 (Ground Spray), 87 (Aerial Spray)
Kelowna 1986 1988  (Aerial and Ground Spray)
Colwood (CFB) 1986 1988 (Aerial Spray)
Belmont Park 1990 1992  (Aerial Spray)
Parksville (North) 1987 1988 (Ground Spray),1990 (Aerial and Ground Spray)
Parksville (South) 1991 1992 (Ground Spray)
North Saanich 1990 1991 (Aerial and Ground Spray)
Richmond 1991 1993 (Aerial Spray)
Burnaby 1992 1993 (Aerial Spray)
Salt Spring Island 1991 1993 (Ground Spray)
South Vancouver area 1991 1994 (Ground Spray)
Victoria 1992 1993 (Aerial Spray), 1994 (Aerial Spray)

View 1993 treatment map
Nanaimo (Beban Park) 1992 1994 (Aerial Spray)

View 1994 treatment map

Whiskey Creek 1992 1994 (Aerial Spray)
Hope 1992 1993, 1994 (Aerial Spray), 1996
Chilliwack 1992 1995 (Aerial and Ground Spray)
New Westminster 1995 1997 (Host removal)
Victoria, Colwood, Esquimalt
(Mass trapping in '97 and '98 failed due to the discovery of high numbers of viable egg masses the fall of '98)
1996 1998, 1999

View 1998 Gd. spray treatment map

Go to 1999 Aerial Spray History page

Duncan, Nanaimo, Brentwood Bay, Tsawwassen, Metchosin
(Fairfield mass trapping was inconclusive)
1998 1999

Go to 1999 Aerial Spray History page

CFIA regulated area

Burnaby 1999 2000

Go to 2000 Burnaby Aerial Spray History page

Sechelt
(*Mass trapping may have been successful at eradicating this population.)
1999, 2000, 2001 2000, 2001
Delta 1998, 1999, 2000  2001

Go to 2001 N. Delta Gd. Spray Page

N. Delta and Saanich
(*Delta mass trapping in '02 and '03 failed due to the discovery of viable egg masses in the fall of '03; Saanich mass trapping in '03 also failed - grid was not located over the epicentre.) 
2001 to 2003 Go to 2004 Aerial Spray Page
*Abbotsford, Duncan and Gabriola Island mass trapping  2003 2004
Duncan, Gabriola Island, Saanich, Langley mass trapping 2003-04 2005
Nanaimo, Saltspring Island, Saanich 2003-05 Go to the 2006 treatment page
Courtenay, Saltspring Island, Cedar Hill Golf Course, Belmont Park (Colwood), 2006 Go to 2007 treatments
Saltspring Island, Saltair, Lake Cowichan 2004 (SS), 2007 Go to 2008 treatments
Harrison 2009 Go to  2009 treatment
Harrison and Richmond 2010 Go to 2010 treatments

* 1979 treatments consisted of an operational trial of two products, Safer's Insecticidal Soap and and Carbaryl. (see Puritch and Brooks, March 1981. Effect of Insecticidal soap using in the gypsy moth control program in Kitsilano on insects and vegetation. BC-X-218)

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The European race has also been found at almost 100 other locations during this same period. At these sites, moths were detected in traps but the authorities did not consider treatment necessary. Usually, these detections were associated with isolated or single catches, with no evidence of gypsy moth being found during the following years of intensive surveillance. The following summary lists those regions where gypsy moth has been found, but control operations were not undertaken or are not planned at this time:
 
Region No. of Locations Year(s) Detected
Greater Vancouver area 40+ 1980-84,1986-96, 99, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 13
Fraser Valley 30+ 1982, 1984-85, 1988-94, 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 13, 14
Sunshine Coast & Howe Sound 4 1990, 1992-93, 99
Greater Victoria area 25+ 1985, 1989-1996, 00, 01, 02, 03, 04, 05, 06, 08, 11, 12, 14
Vancouver Is. 25+ 1986-87, 1989-94, 1996-98, 99, 00, 01, 02 ,03, 04, 05, 06, 07, 09, 10, 13, 14
South central Interior of B.C. 15 1984-86, 1988-92, 00, 01, 02, 04, 06, 08, 09, 10, 11, 12, 13, 14
Northwest Interior of BC 1 1998

The battle with the moth continues.

The program to prevent establishment via intensive surveys and treatment of establishing populations will continue.

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Back to the Gypsy Moth Homepage

 

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Contact Tim Ebata if you have comments on the presentation of this information.

BC Ministry of Forests, Lands & Natural Resource Operations
Resource Practices Branch
P.O. Box 9513 Stn. Prov. Gov.
Victoria, BC
V8W 9C2

Section phone: (250) 387-8739
Section fax: (250) 387-2136