Other insect concerns in blueberries

Transcription

1 Other insect concerns in blueberries Hannah Joy Burrack Department of Entomology entomology.ces.ncsu.edu

2 Topics Blueberry pollinators Blueberry maggot Fruitworm caterpillars in blueberries

3 Blueberry pollinators Which bees pollinate blueberries? What are the best blueberry pollinators? Are more bees better?

4 Which bees pollinate blueberries? 4 Surveyed 4 sites over 2 years Shelley Rogers, MS Student

5 Pollinator community Apis mellifera Bombus spp. Habropoda laboriosa Xylocopa virginica Small native bees Andrenidae Halictidae Osmia cornifrons

6 Pollinator community Apis mellifera Bombus spp. Habropoda laboriosa Xylocopa virginica Small native bees Andrenidae Halictidae Osmia cornifrons

7 NC Native Plants Society Measured single visit pollination efficiency Treatments Pollinator Excluded Pollinator Visit Open Pollinated

8 Kevin Littlejohn waits for a single visit.

9 Results

10 Single visit efficiency is not the whole story Criteria Abundance Per-visit efficiency Description number of actively foraging bees in an agroecosystem (Winfree et al. 2008, Tuell et al. 2009) amount of pollination provided by a bee in a single visit to a flower (Inouye et al. 1994, Ne eman et al. 2010, Artz and Nault 2011) Activity patterns foraging activity that may be dependent on weather (Dogterom 1999, Tuell and Isaacs 2010), seasonal phenology (Cane and Payne 1993), and spatial aspects of bee foraging behavior (Dogterom 1999, Gathmann and Tscharntke 2002, Ratti et al. 2008) Visitation rate number of flowers (or plants) visited over a period of time (Cane and Payne 1988, Ne eman et al. 2010, Artz and Nault 2011) Interspecific influence interactions between bee groups that may reduce or enhance visitation rates or per-visit efficiency (Maloof and Inouye 2000, Greenleaf and Kremen 2006, Rogers et al. 2013)

11 Bee species differ in abundance during bloom Mean forager abundance Floral handling behavior a Early bloom Mid Late Apis bloom bloom Bee group East East West East Sampling periods b Apis mellifera L R Bombus spp. L Habropoda laboriosa L Osmia cornifrons L Small native bees L R Xylocopa virginica R

12 Bee species differ in abundance during bloom, and based on weather

13 Bee interactions are uncommon, but influence behavior Apis Bombus Bumble bees are more likely to leave an arena after encountering a honey bee than after encountering another bumble bee This is likely a good thing!

14 What bees are the best? Apis mellifera Bombus spp. Habropoda laboriosa Xylocopa virginica Small native bees Andrenidae Halictidae Osmia cornifrons Abundant? Yes No Yes No Sometimes No Efficient? No Yes No No Yes Yes Activity limits? Yes No No Yes No Unknown

15 Are more bees better? Bee species diversity positive relates to seed set Our estimates suggest that each additional wild bee group contributes 3.66 seeds/berry Summed over our system, each wild bee group adds ~$1.44 million/year to crop value

16 Feeds on fruit or flowers Key blueberry pests Feeds on stems/branches Feeds on leaves Spotted wing drosophila Blueberry stem borer Blueberry stem borer Thrips Blueberry maggot fly Cherry & Cranberry fruitworms Sharpnosed leafhopper Dormant Prebloom Bloom Fruit Growth Harvest Post harvest

17 Blueberry maggot fly Directly damages fruit, larvae feed internally Quarantine concern for shipment to western US & Canada

18 Blueberry maggot fly Most treatments in NC are motivated by quarantine restrictions No formal monitoring program in place

19 Blueberry maggot fly Distinguishing SWD from other larvae present in blueberries SWD Blueberry maggot Pointed on both ends Black mouth hooks visible on front No legs Pointed on one end Larger when mature No legs

20 Blueberry maggot fly Monitoring methods Yellow sticky (AM) traps baited with external ammonium bicarbonate lures DO NOT use prebaited traps, use AM-NB Check and change bait weekly Hang with fold facing down

21 Blueberry maggot fly Even prior to introduction of SWD, blueberry maggot populations in southeastern NC were extremely low 1559 acres were monitored weekly in 2011 (1007 trap weeks), and 3 flies were captured At one location in western NC, which had never been managed for blueberry maggot, 165 flies were captured in 32 trap weeks

22 Blueberry maggot fly Management All materials effective against SWD are effective against blueberry maggot but not all materials effective against blueberry maggot are effective against SWD

23 Cherry & Cranberry fruitworms Eggs laid in calyx cup on young fruit Pupation occurs in spring, and adults emerge around bloom Larvae overwinter in hibernaculae in soil (CBFW) or in pruning stubs/dead leaves (CFW)

24 Cherry & Cranberry fruitworms

25 Cherry & Cranberry fruitworms Monitoring Pheromone baited traps capture adults and should be placed at beginning of bloom Direct cluster observation to detect damage

26 Cherry & Cranberry fruitworms Management In locations with adult trap captures, treatments should be timed to egg hatch (~3 days after peak trap capture), typically around petal fall Select materials selective for caterpillars (Bt, Intrepid, Confirm, Knack, etc)

27 Read entomology.ces.ncsu.edu Like facebook.com/ncsmallfruitipm Follow