Spotted winged Drosophila Pest of thin-skinned fruit Found throughout the eastern states to North Dakota Can attack sound fruit before they fully ripen

What makes this fruit fly different is the females ovipositor (egg layer), it has teeth to penetrate the skin of fruit Can vector yeasts and bacteria to the berries

Male: Single spot on wing 2 bands on front legs ID Characters Female: a.Enlarged, hardened, toothed ovipositor b.Clear, sharp and straight cross vein a a b b

Spotted winged Drosophila Attack as fruit turn color – Blackberry – Raspberry – Blueberry – Cherry – Strawberry – Grape – Peach

Relative Susceptibility of Fruits Most susceptible – Fall raspberries, blackberries Very susceptible – Blueberries, black raspberries Moderately susceptible – Strawberries (?), grapes (thin skinned), cherries Low susceptibility – Peaches, apples, tomatoes

Traps positive for SWD 2012 Traps negative for SWD 2013 Traps positive for SWD 2013 Reported fruit infestations Spotted Wing Drosophila Distribution

Fruit Damage Signs Early wrinkling and softening seen at 1 to 2 days Soft spots and collapse of berry Small holes created by larvae Breathing tubes maybe visible with eggs Oozing berry sap from egg laying holes Juicy berries Larvae emerging Poor shelf life of fruit

SWD Biology Most active mid-late summer Adults live about 3 or more weeks Females prefer dark, egg laying concentrated in center of plants Move to field as fruit begin to ripen and move out after clean harvest SWD develops on several common wild hosts – poke weed, bittersweet, nightshade

SWD Biology Eggs laid under the skin as fruit ripen Has breathing tubes to surface Translucent small (1/4”) larva (maggot) under skin

What We Learned in 2013 Too late to affect strawberries, black raspberries and early blueberries! – 2014?? Traps alerted growers to SWD presence before damage was noted SWD widespread throughout KY by end of July SWD blackberry and raspberry losses severe across state SWD controls with insecticides can be effective for commercial producers applied correctly

What We Learned in 2013 Grapes, peaches, apples, tomatoes Apparent increases in other fruit flies

Risk Factors – MSU (R. Isaacs) Inter-spray intervals too long Wooded borders Dense canopies Water volume too low Not reapplying after rain Using too low rates Picking intervals too long Using ineffective products

Monitoring is Critical! Egg sampling / 20 x hand lens Larval sampling / sugar water floatation Adult sampling sugar/yeast traps Commercial Growers

Monitoring Examination of susceptible fruit near harvest for larvae Baited traps – Bait: Combine 4 Tbsp sugar, 2 Tbsp yeast, and 2 quart warm water – Use ½ cup bait per trap + 2 drops dish soap – Trap: Clear 1 liter container with many small holes below rim – Place in shady, dense part of canopy – Check weekly – Replace vinegar weekly, do not dispose of vinegar in field Commercial Growers

SWD Floatation Method Can be used to check berries for eggs & larvae Mix ½ cup sugar in 1 quart water Mash suspected berries in plastic bag Add sugar water and shake Berries should sink, maggots float Commercial Growers

Integrated Management (IPM) Monitoring plantings/surrounding areas with traps Reduce alternate host plants in surrounding habitat if practical If spotted wing drosophila is NOT found, DO NOT use SWD insecticides before harvest If SWD IS found, treat crop on 4 to 7 day intervals as fruit begin to color through harvest, retreat after rain Watch Pre Harvest Intervals (PHI) carefully Rotate insecticide chemistries for resistance management Continue to monitor with traps to determine effectiveness Sample fruit for SWD using the fruit-dunk flotation method Consider postharvest clean-up spray to reduce population Commercial Growers

Spotted winged Drosophila SWD insecticides SWD insecticides (From: Various universities) Diazinon7 dayGroup 1B Brigade7 dayGroup 3 Danitol 7 dayGroup 3 Mustang Max 7 dayGroup 3 Baythroid 7 day Group 3 Delegate5-7 day Group 5 Malathion5-7 dayGroup 1B Lannate3 - 5 dayGroup 1A Entrust3 - 5 dayGroup 5 Pyrethrum0 – 2 day`Group 3 Sevin< 1 dayGroup 1A Watch Pre-harvest intervals (PHIs) carefully when spraying in harvest periods Commercial Growers

Pre Harvest Intervals on Small Fruit InsecticideEffectivenessStrawberryCaneberryBlueberryGrape Diazinon7NA 728 Brigade Danitol Mustang Max 7NA111 Baythroid7NA 3 Delegate5-7NA137 Malathion5-73NA 7 Entrust Lannate3NA 31/14* Pyrethrum20000 Sevin17777 Commercial Growers

Recommended Insecticides for SWD Commercial Growers

Getting the Coverage Needed Target for the sprays is to kill the adults before egg laying Flies hide in the dense part of the canopy until temps drop in late afternoon High pressure sprays needed to penetrate dense foliage Mist-blower sprayer - $700 Commercial Growers

Rotation of Modes of Action We know a lot about drosophila genetics With most types of resistance, only a single base-pair substitution is needed. We must rotate MOA with each subsequent sprays Groups 1B, 3, and 5 are most effective Commercial and Backyard Growers

Recommended Insecticides for SWD Commercial Growers

Pesticides During Harvest Issues Mandatory Pre-Harvest Intervals – Food safety issues Overlap of harvest with bloom – Pollinator protection Commercial and Backyard Growers

Cultural Controls Practice Sanitation = Clean harvest – Don’t leave overripe or damaged fruit in the field Harvest and refrigerate immediately Post harvest cleanup Commercial and Backyard Growers

Cultural Controls Select early-ripening varieties when replanting Prune plants to promote an open canopy Reduce wild alternate hosts, if practical May be possible to trap out the flies, traps <30’ apart (more research needed) Commercial and Backyard Growers

Other control measures: Netting <1 mm In place before fruit ripen Commercial and Backyard Growers

May be practical for small plantings – ProTekNet Ultimate Plus (25 gm/m 2 ) – ProtekNet Standard Plus (80 g/m 2 ) – Remay Expensive, must be in place before fruit ripen Secured at the ground Also reduces bird damage Netting for Small Plantings

SWD Factsheets Commercial Growers

Getting Your Flies Identified Send them in to me in Lexington – Provide an for a response Reference samples in alcohol – 2 male, 2 female, 2 larvae SWD – Available at ANR updates for agents – Available for commercial growers at Fruit and Vegetable Conference Commercial Growers

Plastic traps available Up to 2 per county, can be reused with subsequent crops through the summer