Biological and Microbial Control Options for Managing Lygus Bug in Strawberries

Size: px

Start display at page:

Download "Biological and Microbial Control Options for Managing Lygus Bug in Strawberries"

Noah Lyons
5 years ago
Views:

Biological and Microbial Control Options for Managing Lygus Bug in Strawberries Surendra Dara Strawberry and Vegetable Crops Advisor and Affiliated IPM Advisor University of California

1 Biological and Microbial Control Options for Managing Lygus Bug in Strawberries Surendra Dara Strawberry and Vegetable Crops Advisor and Affiliated IPM Advisor University of California Cooperative Extension Santa Barbara and San Luis Obispo Lygus Bug IPM Seminar, UCCE, Watsonville, 18 April, 2013

2 Lygus bug Lygus bug Lygus bug first instar next to aphid, 4 th and 5 th instars, and adult

3 Current pest management practices Chemical pesticides and to a limited extent insecticidal soaps, oils, pyrethrin, spinosad, and Bt Release of predatory mites No major emphasis on biological control of lygus bug

4 Acres treated with insecticides in strawberries Insecticide Acres treated with different insecticides Oil 690 7,408 20,204 36,957 53,860 Novaluron (Rimon) 24,497 41,149 Fenpyroximate (Akari) 41,149 Sulfur 129, , , , ,125 Naled (Dibrom) 18,681 23,819 33,916 51,937 44,587 Spiromesifen (Oberon) 10,375 16,225 18,439 22,485 29,404 Fenpropathrin (Danitol) 20,217 21,272 25,688 27,885 21,229 Abamectin (Agri Mek) 13,024 16,962 26,103 29,751 35,876 Total 191, , , , ,221 Acreage in California 29,187 29,937 31,169 35,915 34,426 Total amount of pesticides in pounds (fungicides, insecticides, and herbicides used) 9,394,745 9,669,764 9,918,143 10,041,462 10,972,995 Pesticide Use Report Data 2010, CDPR

5 Pesticide use in California strawberries 2009 Chemical name Chemical class Trade name Gross pounds Acres treated Bifenazate Unclassified Acramite, Floramite 17,353 35,480 Bifenthrin Pyrethroid Brigade 4,485 41,235 Chlorpyrifos Organophosphorus Lorsban 11,323 11,384 Fenpropathrin Pyrethroid Danitol 9,243 27,783 Malathion Organophosphorus Malathion 144,417 76,208 Methomyl N methyl carbamate Lannate 6,104 7,641 Naled Organophosphorus Dibrom 48,723 51,689 Spiromesifen Keto enol Oberon 5,338 22,477 Total 246, ,897 Pesticide Action Network North America

Biocontrol agents and basics www.state.nj.

6 Biocontrol agents and basics Egg parasitoid, Anaphes iole Nymphal parasitoid, Peristenus stygicus Lygus adult killed by Beauveria bassiana Multiple natural enemies for different life stages of pest Conserving natural enemies Providing refuge for natural enemies Using chemicals that are less disruptive to natural enemies

7 Seasonal occurrence of lygus bug Conventional strawberry field Nymphs Adults Treatment threshold 1 nymph No. of Lygus per 20 strawberry plants Danitol Dibrom & Rimon Dibrom Danitol Dibrom & Rimon Brigade & Rimon Malathion & Rimon Malathion Dibrom

8 Seasonal occurrence of lygus bug Organic strawberry field No. of Lygus per 20 strawberry plants Nymphs Adults Treatment threshold

9 Generalist Predator Gut Content Analyses Lygus bug predation rates of field collected predators (via PCR)* J. Hagler, D. Nieto, S. Swezey, S. Machtley and J. Bryer Big eyed bug (N = 84) % preyed upon lygus bugs: 13% Minute pirate bug (N = 286) % preyed upon lygus bugs: 14% Damsel bug (N = 108) % preyed upon lygus bugs: 20% Crab spider (N = 89) % preyed upon lygus bugs: 26% *preliminary data

Fig. 1. Seasonal trends in Lygus densities and proportion parasitized by P. relictus. Wild vegetation release sites, Castro1 and Harkins Slough. Averaged over July, August, and September.

0 first release a Castro1 density nymphs parasitism 2002 2004 2006 2008 2010 2012 1.0 0.8 0.6 0.4 0.2 0.

10 Fig. 1. Seasonal trends in Lygus densities and proportion parasitized by P. relictus. Wild vegetation release sites, Castro1 and Harkins Slough. Averaged over July, August, and September. Parasitism of lygus bug nymphs by the introduced parasitoid Peristenus relictus C. Pickett, S. Swezey, D. Nieto and J. Bryer MEAN NYMPHS PER SWEEP AND SEM first release a Castro1 density nymphs parasitism PARASITISM AND SEM a missing data for parasitism in 2004 Photo by Charles Pickett MEAN NYMPS PER SWEEP AND SEM first release Harkins Slough density nymphs parasitism PARASITISM AND SEM YEAR OF SAMPLING

11 Alfalfa Trap Crops and Yield (2012)* D. Nieto, S. Swezey and J. Bryer mean % damage mean # undamaged berries/plant berries with TC berries with TC berries without TC berries without TC *preliminary data Field data from 2012 organic strawberries in rows 1 4, 7 10, and adjacent to an alfalfa trap crop (TC) and control row of strawberries

12 Potential of entomopathogens Entomopathogens like Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea are pathogenic to most of the strawberry pests Lygus Spider mites Thrips Whitefly health.co.za/eco bb.html fichiers/22512/ch01.html

13 How entomopathogenic fungi infect insects

14 Potential of entomopathogens Hosts Min: o F Max: o F Avg: o F Entomopathogens Environment

15 Possible microbial control strategy Incorporating microbial control into IPM Foliar application alone and along with chemical pesticides Endophytic colonization of the strawberry plants

16 Impact on strawberry IPM Reduces the chemical pesticide use Reduces the risk of pesticide resistance Extends the life of effective chemicals Improves the pest management Enhances the efficacy of IPM

17 Chemicals and B. bassiana against Lygus Objectives Improve the efficacy of B. bassiana Reduce the usage of chemicals Treatments 0.19 lb/ac or 1X10 7 conidia/ml of BotaniGard 22 WP (label rate 1/2 2 lb/acre) 1/5 the label rate of Actara (1 pt/ac), Aza Direct (2 qrt/ac), Danitol (11 oz/ac) and Dibrom (1 pt/ac)

18 Chemicals and B. bassiana against Lygus

19 Chemicals and B. bassiana against Lygus

20 Chemicals and B. bassiana against Lygus 100 Cumulative mortality (%) Days after treatment Control Actara Aza Direct BotaniGard 22 WP Danitol Dibrom Actara+BotaniGard Aza Direct+BotaniGard Danitol+BotaniGard Dibrom+BotaniGard

21 Endophytic colonization Objectives What is an ideal method of inoculation? Does the fungus colonize strawberry plants? If it does, how long does it persist in the plant? Does the colonized fungus protect the plant from herbivore damage?

22 Endophytic colonization B. bassiana Rinsed, surface sterilized and rinsed the plant material Plated plant tissue on selective medium Plated rinsate on medium to verify contamination

23 Endophytic colonization B. bassiana Roots Petioles Emergence of colonized B. bassiana from treated plant tissue No B. bassiana detected in controls Leaves

24 Endophytic colonization B. bassiana Root Petiole Leaf lamina

25 Endophytic colonization M. anisopliae M. anisopliae treated plants 10 DAT: 44% plants damaged 14 DAT: 56% plants damaged 10 DAT: 59% plants damaged 14 DAT: 65% plants damaged Untreated control plants

26 Small plot field trial 2010 Treatments 1 st 8/20 2 nd 8/27 3 rd 9/2 4 th 9/9 Average number per plant On flowering hosts 1 3 instar nymphs 4 5 instar nymphs Adults 0 8/16/2010 8/25/2010 8/27/2010 9/2/2010 9/8/2010 9/10/2010 9/16/2010 Days before or after treatment

BotaniGard WP 2lb/ac + Danitol (fenpropathrin) ½ label rate 5.3 fl oz/ac in 50 gal 6. BotaniGard WP 2lb/ac + Assail ½ label rate 1.

27 Large field trial 2012 Treatments: 1. Untreated control 2. Assail 70 WP (acetamiprid) 3 oz/ac in 50 gal 3. BotaniGard WP (Beauveria bassiana) 2lb/ac in 50 gal 4. BotaniGard WP 2lb/ac + Molt X (azadirachtin) 8 fl oz/ac in 50 gal 5. BotaniGard WP 2lb/ac + Danitol (fenpropathrin) ½ label rate 5.3 fl oz/ac in 50 gal 6. BotaniGard WP 2lb/ac + Assail ½ label rate 1.5 oz/ac in 50 gal 7. AzaGuard (azadirachtin) 8 fl oz/ac in 50 gal 8. AzaGuard 16 fl oz/ac in 50 gal 9. Rimon 0.83 EC (novaluran) 12 fl oz/ac + Brigade (bifenthrin) 16 oz/ac in 50 gal Experimental period: July August, 2012

28 Large field trial Lygus populations following each spray application Pre treatment I Spray II Spray III Spray Number of lygus bugs/20 plants Untreated Acetamiprid Novaluron + Bifenthrin B. bassiana Bb + Azadirachtin Bb + 1/2 Fenpropathrin Bb + 1/2 Acetamiprid Azadirachtin (8 fl oz) Azadirachtin (16 fl oz)

29 Large field trial 2012 Lygus populations before and after treatment Pre treatment Post treatment 15 Number of lygus bugs/20 plants Untreated Acetamiprid Novaluron + Bifenthrin B. bassiana Bb + Azadirachtin Bb + 1/2 Fenpropathrin Bb + 1/2 Acetamiprid Azadirachtin (8 fl oz) Azadirachtin (16 fl oz)

30 Miticide trial 2012 Mobile predatory mites Number of predatory mites/leaflet 0 DAT 3 DAT Nymphs and Adults Neoseiulus spp.

31 Conclusions Conserve biocontrol agents to exploit their potential Microbial and botanical solutions have a good potential in strawberry IPM B. bassiana+ ½ acetamiprid, B. bassiana+azadirachtin, and azadirachtin did fairly well compared to chemicals for lygus control Consider combinations of reduced rates of chemicals and other options for good IPM

32 Compatibility of B. bassiana and fungicides Lab assay with mealworms (Tenebrio molitor), B. bassiana, and some common strawberry fungicides

33 Compatibility of B. bassiana and fungicides Dead Infected Mean percent mortality/infection e d a a cd de ab ab cd cd a a bc bc de de cd c Average of 6 assays

34 Compatibility of B. bassiana and Pristine

35 Conclusions Elevate and Quintec are compatible with B. bassiana B. bassiana was not affected by Pristine when applied after one day. Other fungicides may be compatible with appropriate time intervals.

36 Acknowledgments Grower Dave Peck Technical assistance Jacob Conway Maria Murrietta Thomas Crottogini Sumanth Dara Pesticide Industry Curt Engle, United Phosphorus Eduardo Garcia, Chemtura Randy Martin, BioWorks Inc Pest infestations

Update on microbial control of arthropod pests of strawberries

Update on microbial control of arthropod pests of strawberries Surendra Dara Strawberry and Vegetable Crops Advisor Santa Barbara and San Luis Obispo Counties University of California Cooperative Extension