Swede MidgeContarinia nasturii

Ellis, Hoepting, and Hodges. July 2007.NPDN Publication No. 0017

Outline• Introduction

• Identification

• Life Cycle

• Damage/Symptoms

• Distribution

• Regulatory Status

• Control

Photo: Susan Ellis, www.forestryimages.org

Order DipteraFamily Cecidomyiidae

Contarinia nasturtii (Kieffer)

Introduction In 2000, the swede midge was identified in

York County, Ontario. During 1996, incidence escalated to as

high as 85% in broccoli but the problem was misdiagnosed as a nutrient deficiency.

Photo: Susan Ellis, www.forestryimages.org

Introduction• In 2004, the swede midge was recorded in

Niagara County, New York.

• In 2005, researchers collected positive samples from adjacent counties.

• Cornell scientists have estimated that New York could lose a portion of its $70 million crucifer acreage if the swede midge is not properly managed.

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Introduction In parts of Europe, the swede midge has

caused serious economic damage and crop loss of Brassica and other related crucifers

Current Distribution:– Asia – Turkey– Europe – widespread– North America – Canada (parts of Ontario and

Québec); USA (New York)

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Photos: Susan Ellis, www.forestryimages.org

Adult Female

IdentificationAdult Male

Identification• Eggs – minute and

not visible with hand lens

• Early instar larvae-transparent

• Mature larvae - small maggots, 3-4 mm long and yellow in color

Photo: Susan Ellis, www.forestryimages.org

Larva

Life Cycle• 4-5 generations

have been observed

Photo: Mao Chen, Cornell University, www.forestryimages.org

Pupa

Life Cycle• Pupae overwinter in the soil and adults

emerge May-June.

• Adults are not strong fliers so their distribution area is limited.

• Adult flies mate and females oviposit on the first available plant, laying eggs in strings or clusters of 2-50 eggs on the youngest parts of the plant.

• The female can lay about 100 eggs during her lifetime of only 1-5 days.

Life Cycle• Larvae:

– Hatch after 3 days and feed on tissue near growing points of the plant (flower buds, base of leaf stalks, or apical meristem)

– Produce a secretion that breaks down the plant surface and liquefies the contents of the cell.

– Mature in 2-3 weeks and drop to the ground and spin cocoons in the soil.

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Life Cycle• During summer months, eggs hatch and fee

gregariously as larvae for 2-3 weeks prior to pupation in the soil.

• During drought, larvae may enter a period of dormancy, but growth resumes after a rainfall.

• In the fall, pupae sense the short day length and go into a state of diapause for the winter.

• Some pupae may overwinter a second season before becoming adults.

Photo: Mao Chen, Cornell University, www.forestryimages.org

Hosts• Include a wide range of species within the

family Brassicaceae (or Cruciferae), which includes the following: – Broccoli (B. oleracea var. italica)– Cauliflower (Brassica oleracea var. botrytis)– Cabbage (B. oleracea var. capitata)– Radish (Raphanus sativus)

Photo: Mary Ellen (Mel) Harte, www.forestryimages.org

RadishCabbage

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Damage/Symptoms• Difficult to diagnose symptoms caused by

swede midge because of the similarity to abnormalities that can be caused by the following:– mechanical injury from cultivation, – insect and animal feeding, – molybdenum deficiency, – herbicide injury,– heat or cold stress, – frost damage, or – genetic variation of the plant.

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

• Infested growing tips can be placed in a 95% ethanol solution.

• Damage severity increases as the number of larvae per plant increases and when plants are infested earlier during development.

Damage/Symptoms

Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Damage/Symptoms• The most obvious symptom is “blind

heads” or “blindness” which is caused by the disruption or lapsing of growth at the terminal growing point of the plant.

Photos: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

• Larval feeding results in changes in the physiology of the plant and the formation of leaf and flower galls and misshapen growing point.

Photos: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Damage/Symptoms

• The larvae’s salivary secretions cause the plant to twist and deform, leading to swollen flower buds, crinkled heart leaves, and swollen, distorted and twisted shoots and leaf stalks.

Damage/Symptoms

Photos: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

Distribution

Prepared for the Cooperative Agriculture Pest Survey (CAPS) program following 2005 surveys http://ceris.purdue.edu/napis/pests/swmdg/imap/swmdgall.html

Distribution

Credits: USDA Zone Hardiness MapEllis 2005

Regulatory Status

• Source: Ellis, S.E. 2005. New Pest Response Guidelines: Swede Midge Contarinia nasturtii (Kieffer). USDA-APHIS-PPQ Emergency and Domestic Programs, Riverdale, Maryland. http://www.aphis.usda.gov/import_export/plants/manuals/online_manuals.html

• Online May 21, 2007

Regulatory StatusRegulatory Articles-Ellis 2005• Cole crops• Soil from within the drip area of host

plants, regardless of whether or not plant is viable.

• Transplants or seedlings• Machinery used in culitivation• Any other product or article that could

spread swede midge

Regulatory StatusQuarantine Actions-Ellis 2005The following circumstances could result in

regulatory action:• More than 1 adult in an area less than 100

square km within 1 estimated life cycle• 1 mated female, a larva, or pupa detected• A single adult fly is detected and

associated with a current eradication project

Control• The best control is to limit the spread of

the pest– Movement of transplants that may contain

eggs or larvae – Movement of soil that may contain pupae.

• Growers are advised…– To chop and deep plow cruciferous crop

residue– To rotate a field to another crop

If you suspect a problem…If you suspect a problem…• Contact your local cooperative extension Contact your local cooperative extension

serviceservice– http://www.csrees.usda.gov/qlinks/partners/http://www.csrees.usda.gov/qlinks/partners/

state_partners.htmlstate_partners.html

• Submit a sample to a NPDN diagnostic labSubmit a sample to a NPDN diagnostic lab – http://www.npdn.org

Photo: Susan Ellis, www.forestryimages.org

Selected References• APHIS, USDA. Pest alert: swede midge.

http://www.aphis.usda.gov/ppq/ep/emerging_pests/swedemidge.html• Canada Food Inspection Agency. 2005. Contarinia nasturtii (Kieffer) –

Swede Midge. http://www.inspection.gc.ca/english/sci/surv/data/connase.shtml

• CERIS. 2006. Pest Tracker – Swede Midge, Cabbage Gall Midge. http://ceris.purdue.edu/napis/pests/swmdg/index.html

• Hallett, R.H., and J.D. Heal. 2001. First nearctic record of the swede midge (Diptera: Cecidomyiidae), a pest of cruciferous crops from Europe. The Canadian Entomologist 133: 713-715.

• Kikkert, J.R., Hoepting, C.A., and Shelton, A.M. 2003. Insects of crucifers – Swede midge. Cornell Cooperative Extension. http://www.nysipm.cornell.edu/factsheets/vegetables/cruc/sm.pdf

• Callow, K. Ontario Ministry of Agriculture, Food and Rural Affairs. 2003. The swede midge – a new pest in crucifer crops in Ontario. http://www.omafra.gov.on.ca/english/crops/facts/03-035.htm

• North American Plant Protection Organization, Phytosanitary Alert System. 2002. Contarinia nasturtii (Kieffer). http://www.pestalert.org/Detail.CFM?recordID=77

Background Photo: Julie Kikkert, Cornell Cooperative Extension, www.forestryimages.org

AcknowledgmentsEditorial Review

• Dan Gilrein, Extension Entomologist, Cornell University Cooperative Extension of Suffolk County

Authors• Amanda M. Ellis

University of Florida, SPDN

Currently, Florida Department of Agriculture & Consumer Services, Division of Plant Industry

• Christine A. Hoepting, cah59@cornell.edu

Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program, Cornell University

• Amanda C. Hodges, Ph.D., achodges@ufl.edu

SPDN Associate Director, University of Florida

Publication Details• This publication can be used for non-profit,

educational use only purposes. Photographers retain copyright to photographs or other images contained in this publication as cited. This material was developed as a topic-based training module for NPDN First Detector Training. Authors and the website should be properly cited. Images or photographs should also be properly cited and credited to the original source.

• Publication Number: 0017• Publication Date: July 2007