Swede Midge Contarinia nasturii Ellis, Hoepting, and Hodges. July NPDN Publication No. 0017

Outline Introduction Identification Life Cycle Damage/Symptoms Distribution Regulatory Status Control Photo: Susan Ellis, Order Diptera Family 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,

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,

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,

Photos: Susan Ellis, Adult Female Identification Adult 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, Larva

Life Cycle 4-5 generations have been observed Photo: Mao Chen, Cornell University, 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,

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,

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, Radish Cabbage Photo: Julie Kikkert, Cornell Cooperative Extension,

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,

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,

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,

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, 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,

Distribution Prepared for the Cooperative Agriculture Pest Survey (CAPS) program following 2005 surveys

Distribution Credits: USDA Zone Hardiness Map Ellis 2005

Regulatory Status Source: Ellis, S.E New Pest Response Guidelines: Swede Midge Contarinia nasturtii (Kieffer). USDA- APHIS-PPQ Emergency and Domestic Programs, Riverdale, Maryland. lants/manuals/online_manuals.html lants/manuals/online_manuals.html Online May 21, 2007

Regulatory Status Regulatory 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 Status Quarantine Actions-Ellis 2005 The 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… Contact your local cooperative extension serviceContact your local cooperative extension service – te_partners.html Submit a sample to a NPDN diagnostic labSubmit a sample to a NPDN diagnostic lab – Photo: Susan Ellis,

Selected References APHIS, USDA. Pest alert: swede midge. Canada Food Inspection Agency Contarinia nasturtii (Kieffer) – Swede Midge. CERIS Pest Tracker – Swede Midge, Cabbage Gall Midge. Hallett, R.H., and J.D. Heal First nearctic record of the swede midge (Diptera: Cecidomyiidae), a pest of cruciferous crops from Europe. The Canadian Entomologist 133: Kikkert, J.R., Hoepting, C.A., and Shelton, A.M Insects of crucifers – Swede midge. Cornell Cooperative Extension. Callow, K. Ontario Ministry of Agriculture, Food and Rural Affairs The swede midge – a new pest in crucifer crops in Ontario. North American Plant Protection Organization, Phytosanitary Alert System Contarinia nasturtii (Kieffer). Background Photo: Julie Kikkert, Cornell Cooperative Extension,

Acknowledgments Editorial 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, Extension Vegetable Specialist, Cornell Cooperative Extension Vegetable Program, Cornell University Amanda C. Hodges, Ph.D., 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