White Grubs and Other Bad Blueberry Bugs

1. White Grubs and Other Bad Blueberry Bugs Dr. Sridhar Polavarapu Blueberry and Cranberry Research and Extension Center Rutgers University Chatsworth, NJ 08019

2. In This Presentation …. • Seasonal lifehistory and management of above ground pests • Pests feeding on roots

3. Seasonal Lifehistory and Management of Major Pests • Pests that occur during the dormant stage • Pre-bloom leaf and flower feeders • Bloom-time insect pests • Post-bloom pests on foliage and fruit

4. Pests During Dormant Stage • Putnam scale is the main concern • Problem in under-pruned fields • Superior oil (70-second type) @ 3 gal/ac • Lime sulfur @ 5 gal/ac • Apply on warm days (>50 F) before flower buds begin to open

5. Pre-bloom Leaf and Flower-Feeders • Cranberry weevil, leafrollers, and spanworms are the major pests • ET of one larvae per 100 clusters for caterpillars • For CW, treat if >5 weevils per bush or 20% injured flower clusters

6. Bloom-time Insect Pests • Gypsymoth larvae, leafrollers, and aphids are the main concern • Bts and Confirm 2F are the insecticide options • Same threshold as pre-bloom • No aphid controls during bloom

7. Post-bloom Pests on Foliage and Fruit • Cranberry fruitworm, plum curculio, blueberry aphids, and blueberry maggot are the major pests • Leafminers, and leafrollers are occassional problems • Most insecticide applications are made during this phase

8. Post-bloom Pests on Foliage and FruitCranberry fruitworm • Single generation per year • Pheromone traps are used for monitoring • Single insecticide application 5-7 days after the peak • Typical timing June 1-5

9. Confirm Diazinon Confirm Confirm Control 6/1 6/1&6/8 6/1&6/8 5/25&6/1 Effect of timing of Confirm 2F applications on efficacy against Cranberry Fruitworm 20 Larvae per 100 Clusters 15 % Damaged Clusters a a 10 b 5 a b b b b b b b 0 CFW 2000

10. Post-bloom Pests on Foliage and FruitBlueberry aphids • A complex of several species • Vectors of blueberry scorch • and other viruses • Species identified in NJ blueberries • Illinoia azaleae • Ericaphis spp. • Macrosiphum euphorbiae, M. rosae • Aphis spiraecola, A. gossypii • Myzus persicae

11. Post-bloom Pests on Foliage and Fruit Constraints in Managing Blueberry Aphids Natural enemies • Low tolerance because of vector status • Use of broadspectrum insecticides • leading to natural enemy destruction • Poor coverage

12. Evaluation of Imidacloprid Applied as Soil Drench Against Blueberry Aphids • Imidacloprid treatments at 0.25 and 0.5 lb A.I./acre were evaluated as soil drench • Four replications, 3 bushes per replication • Insecticide was applied in 1000 mL per bush on June 7 • Aphids were sampled on June 14 and 21

13. 80 % IT 60 40 20 Pre-spray 6/7 1st Post-spray 6/14 Total Aphids 300 2nd Post-spray 6/21 200 100 0 Imidacloprid 0.25 lb.ai/ac Imidacloprid 0.5 lb.ai/ac Control Evaluation of imidacloprid applied as soil drench a a a a a a a b b a ab a a a b a b b

14. Evaluation of Foliar Applications • Imidacloprid, Thiamethoxam, and Thiacloprid were evaluated • Four replications, four bushes per replication in a single row • R&D sprayer, 30 gal/acre, Conejet 4VS hollowcone nozzle • Insecticides were applied twice on June 6 and 13 and aphids sampled on June 6, 12, and 21

15. Pre-Spray , 6/6 Post-Spray, 6/12 Post-Spray, 6/21 80 Total Aphids % IT 60 300 40 20 200 100 Control Calypso Calypso Provado Actara 25 480 SC 1.5 480 SC 3.0 1.6 F 3.0 WDG fl.oz/ac fl.oz/ac fl.oz/ac 85.2g/ac Evaluation of foliar application of insecticides a a a a a a a b bc b c bc c c c a a ab abc bc c a b bc b c c bc c c

16. Post-bloom Pests on Foliage and FruitBlueberry maggot Overwinters in the pupal stage Adults emerge beginning June 10 Females need 10 days to become reproductively mature Calendar sprays begin 10 days after adult emergence

17. Blueberry Maggot Management • Quarantine pest • Wide-window of emergence and oviposition • Presence of wild and voluntary sources of infestation • Research focus on monitoring and timing of insecticide applications

18. Blueberry Maggot Export Regulations • CFIA promulgated new regulations in 1999 • To qualify for export, grower must participate in a BM Certification Program • Growers are required to follow either a calendar-based or IPM-based approach for BM management • Major constraint in IPM adoption

19. Blueberry Maggot Population Monitoring • Yellow boards • - hue • - reflectance • Spheres • - shape • - intensity • contrast with • background Pherocon AM trap Currently recommended for monitoring Red Sphere Green Sphere

20. Insecticide-treated Spheres for Blueberry Maggot Control • Ammonium acetate/carbonate • Color • Shape • Fruit volatiles • Sugar • Proteins

21. Root-feeding Pests - Oriental Beetle

22. White Grub Rastral Patterns Oriental Beetle May-June Beetle Asiatic Garden Beetle

23. Evaluation of Imidacloprid and Insecticidal Nematodes Against Oriental Beetle

24. Imidacloprid for Scarab Grub Management • Applied as a 40cm-wide band on each side of the bush • Works best against 1st instar larvae • Apply in early June to mid-July • Irrigate before and after application • Apply in the evening hours • Current blueberry registration allows only a maximum of 0.3 lb AI/acre/year for grub control • The other 0.2 lb AI/acre/year is used for foliar control of aphids

25. Greenhouse Evaluation of Insecticidal Nematodes and Chloronicotinyls - 2001 12 8 4 0 Hb 3.0 Hb 1.5 Control Imid. 0.75 S new 1.5 Imid 1.5 Thia. 0.6 S new 3.0 S new 0.75 Imid. 0.37 Imid 0.37+ new-S 0.75 # of Grubs Treatment

26. Root-feeding Insects Blueberry Mealybug • Ant-mealybug relationship • Disrupt this relationship for control

27. Any Questions ?