Understanding Peach Tree & Peach Twig Borer. Michael R. Bush, Ph.D. WA State Extension

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1 Understanding Peach Tree & Peach Twig Borer Michael R. Bush, Ph.D. WA State Extension February 5, 2008

2 Peachtree Borer Synanthedon exitiosa One of several clearwing moths Family Sesiidae Striking colorations Wasp/bee mimics Hover & buzz

3 Peachtree Borer- Adults & Hosts Males & females come in different colors Native to North American Wide host range- peach, cherry & plum both cultivated & wild.

4 Peachtree Borer- Signs of Damage Larvae feed on tree trunk at or below soil Copious sap or gum Sawdust & frass within gummy mess Look for cast pupal skins Larvae can girdle & kill Prunus.

5 Peachtree Borer- Larvae & Damage Cream to pinkish white coloration on larvae Brownish head Larvae bores under wood immediately Mature larva is up to 1.5 Most damage occurs late May to June.

6 Peachtree Borer- Life History Completes life cycle in one, maybe two years Insecticides target the newly-hatched larvae Last week of June to early September

7 Pest species ID is Rather Important American Plum Borer damage is similar to peach tree borer. Digital Diagnosis Service Spray timing has to be different.

8 Peachtree Borer- Management Lorsban 4E - Spray trunks, crotches ONLY; cover sprays after delayed dormant are off-label Limited to one spray- Early to mid July.

9 Peachtree Borer- Management Endosulfan - Spray trunks, crotches 1 st Spray- Last week of June, early July. Two sprays may be needed. Note PHI Interval differs by application & Max limit (21 versus 30 days).

10 Peachtree Borer- Management Asana - Spray trunks, crotches 1 st Spray- Last week of June, early July. Two sprays may be needed. Broad-spectrum product may flair mites.

11 Peachtree Borer- Management Alternative to sprays Mating disruption with Isomate-P Utah studies- Zero trap catch no damage in treatment blocks. Use search function

12 Peachtree Borer- Management Other Strategies White Latex paint (1:1 dilution) Tree wraps- remove them by summer Keep base free of weeds Shove wire into entry holes in late fall.

13 Peach Twig Borer Anarsia lineatella One of largest microlepidoptera families Family Gelechiidae Leaf miners, gall formers, leaf rollers. Labial palps long & upcurved

14 Peach Twig Borer-- Adults & Hosts Not Native An European import 1 st found in CA in 1880 s Host range- peach, plum, & apricot.

15 Peach Twig Borer Signs of Damage Wilting & flagging of new shoot growth in Spring

16 Peach Twig Borer Signs of Damage Later in the year, larvae feed on fruit as well as shoots.

17 Peach Twig Borer- Larvae Dark brown head & prothorax Alternating cream and dark brown bands ½ long when mature

18 Peach Twig Borer- Life History Goes through multiple generations per season Insecticides target the newly-hatched larvae The key is target the overwintering generation with sprays at delayed dormant and bloom.

19 Pest species ID May Be Important Oriental Fruit Moth damage is similar to peach twig borer. WSDA Survey shows OFM in WA-spotty distribution Spray timing has to be different (models exist)

20 Peach Twig Borer- Management Dormant or delayed dormant application of Horticultural oil PLUS Spinosad (Entrust or Success) Or Pyrethroid (Asana).

21 Peach Twig Borer- Management Sprays around bloom time Bacillus thuringiensis 2-3 applications per generation Must be timed during warm weather

22 Peach Twig Borer- Management Sprays at petal fall Spinosad (Entrust or Success)- will hit leafrollers pretty well too Imidan, Dimilin, Intrepid

23 Peach Twig Borer- Management Mating disruption does exist for peach twig borer Has not been reliable against peach twig borer when used alone Dual dispensers for PTB & for OFM- Mating disruption effective against OFM.

24 Alternatives to Guthion & Codling Moth %Codling Moth Control 100 Control of codling moth (Cydia pomonella) fruit entries; Fowler IN, 2005 (Field-treated fruit collected at specified time points and infested with codling moth eggs) Trademark of Dow AgroSciences LLC. DELEGATE WG, 6 oz/a Guthion 50W, 1.5 lb/a Spinosad 240 SC, 6 fl.oz./a Days After Treatment

25 WSU s AgWeatherNet Weather Monitoring Up to date weather reports Month to date weather Disease models Degree-day models Link to fruit pest webpage

26 WSU s Decision Aid System Insect & Disease Models Codling moth Apple maggot Fireblight Uses data from AgWeatherNet 10-day forecast WSU s Crop Protection Guide Select an pesticide option, get WSU recommendations & find out how the option impacts other insects.

27 Understanding Peach Tree & Peach Twig Borer Summary Tree Borer- Mating disruption works well, well-timed trunk sprays Twig Borer- Mating disruption not so well, well-time sprays at bloom & petal fall; New product- Delegate w/ improved efficacy There are tables & websites to help AgWeatherNet Decision Aid Contact Mike Bush