Bee Pollination of Tree Fruits & Berries in Virginia

Nancy Adamson, Richard Fell, Donald MullinsVT Entomology Department

(an expanded version of a presentation to VirginiaState Beekeepers on16 April 2010)

Program Overview

Tree fruits & berries grown in Virginia

Colony recommendations

Pollination research on non-Apis bees & a little more pollination biology

honey bee to peach

Rosaceae (rose family) apple & crab apple, pear,

serviceberry, quince caneberry (raspberry,

blackberry, black raspberry, wineberry)

peach, plum, nectarine, apricot

strawberry

Other fruit families Cucurbitaceae (cucurbit):

watermelon, musk melon Annonaceae (custard-apple):

pawpaw Grossulariaceae: gooseberry,

currant Ebonaceae (ebony): persimmon Caprifoliaceae (honeysuckle):

elderberry Actinidiaceae (Chinese

gooseberry): kiwi Passifloraceae: passion flower Cactaceae (cactus): prickly pear

Ericaceae (heath family) blueberry, cranberry,

huckleberry

Insect pollinated* fruit grown in Virginia

* Grapes and mulberries don’t depend on insects—can you think of others?

Most fruit crops benefit from cross-pollination Some crop varieties* require cross-pollination

apples, blueberries, cherries, kiwis, persimmons, sunflowers, caneberries**, and hemp (McGregor 1976, Free 1993, McConkey 2009)

*Variety is a horticultural term for plants of one species with specific characteristics• Red Delicious, Fuji, and Pink Lady apples• Bing and Rainier cherries

two apple varieties

Many caneberries** are sold as self-fertile

** Caneberries are raspberries, blackberries, black raspberries, etc.

bumble bee on blackberry

halictid bee on raspberry

Autumn Bliss (l) & Josephine (r) raspberries

Self-fertile plants—cross-pollination improves size and shape

Cross-pollination requirements/recommendations vary tremendously by variety Pollenizers are the pollen “donors” Crab apples are often used as pollenizers in apple cultivation• Bill Frieman of Doe Creek Orchard in Pembroke, VA prefers to use

compatible saleable varieties

Here, 2 varieties are in different rows

Notice larger flowers in left variety

Cross-pollination needs vary by variety

Check with nurseries for pollenizer requirements

Especially important to match pollenizers to the harvest variety by bloom time

Many of these cherry varieties are self-sterile

Some are cross-incompatible* (for ex. Emporer Frances, Bing, & Kristin)

* Cross-incompatible varieties cannot pollinate one another

http://freedomtreefarms.com/charts/cherry/

cherry pollination chart

Pollination requirements and flower structure:more ovaries require more visits

Prunus spp.: plums, cherries, peaches, apricots & almonds very early spring flowering, single* ovary forms “stone” fruits, drupes

*One visit may be adequate if the female parts are receptive, the pollen viable, and the varieties compatible.

single ovary

pollen

Flower parts may mature at different times—promotes cross-fertilization (vigor in the big scheme)

Malus spp.– apples and crab apples 5 ovaries need multiple visits, generally proterogynous (pollen is

shed after stigma is no longer receptive--prevents self-fertilization)

apple flowers & andrenid bee

stigma

(female)

anther(male)

ovaries

Aggregate* & accessory fruits (multiple ovaries & visits)

Rubus spp. – caneberries (drupelets) Fragaria spp.– strawberries (seeds are achenes)

raspberry

strawberry

blackberry

*Fleshy fruit forms from ovary. Accessory fruit (strawberries and apples) flesh forms from non-ovarial tissue.

Vaccinium spp.—blueberries & cranberries Ribes spp.—currants, gooseberries Asimona triloba--pawpaw

True berries—single ovary, multiple seeds & visits

cranberry

gooseberry

blueberry

* fetid flower odor attracts fly and beetle pollinators

photo courtesy of Margie Adamson

pawpaw*

Dr. Fell* recommends 1 to 2 honey bee colonies/acre for tree fruit (~1 to 3 are recommended for berries)

Some self-sterile, cross-incompatible, or low sugar nectar crops need more colonies Red Delicious apples,

plums, pears

http://freedomtreefarms.com/charts/cherry/

plum pollination chart

* Dr. Richard Fell is the Apiculture Extension Agent at Virginia Tech

Some single ovary early bloomers may not benefit from introduced honey bee colonies

Stone fruits, like peaches & nectarines, require thinning by hand (apples can be chemically thinned)

honey bee on peach

single stigma(leads to ovary)

Bees tend to move down rows—best to interplant pollenizers

Dwarf and semi-dwarf stock may need more colonies dwarf stock=more densely planted

http://www.taranakifarm.com

In this orchard layout, pollenizers are

interplanted

Fell’s “rule of thumb” for farmers to determine if there are adequate bees in orchards

Monitor number of bees in 1 tree on a warm, sunny day 30 seconds OK if 8 to 12 bees(including bumble, mason,and mining bees)

Average at several trees, at various distances from colonies

Osmia (mason bee) on apple

Tricky, huh?

Questions before moving on to pollination research?

Is a global pollinator decline affecting Virginia?

1

Periodic honey bee disease cycle since 1915 approximately 15 to 20 year

cycle (Johnson 2010, Morse and Flottam 1997)

Status of Pollinators in N. America, 2007 (Natural Resource Council of the National Academy of Science)

Baseline data needed

Increasing pollinator dependent crop acres (Aizen 2008)

Primary research objective

halictid bee on blueberry

Investigate the role of native and other non-Apis bees in pollination of entomophilous* crops in southwest Virginia

Available Virginia crop values: apples $37.7 million apple industry value=$235 million (USDA-NASS 2009, VA Apple Board 2010)

tomatoes $88.3 million (USDA-NASS 2006)** cucumbers $4.3 million (USDA-NASS 2006)

watermelons $3.6 million (USDA-NASS 2006)

**Not dependent on bees (except in greenhouses)—bee pollination improves yield & quality in field grown tomatoes.

*Entomophilous derives from Greek for “insects” and “that which is loved.” Unlike wind pollinated plants, entomophilous plants attract insects with nectar, etc.

Study Area in SW Virginia

Undergraduate researcher, Jennifer Kilby, collecting bowl trap specimens

at a caneberry site

Virginia

Blacksburg

Methods: Bee Surveys & Pollen Samples

Survey bees in apple, blueberry, caneberry, & cucurbits• Survey only when weather

conducive to bee activity

• Visual counts & netting at flower at peak flowering time

• Bowl traps (for overall site species richness)

• Pollen load samples (netted at flower)

orchard beeon apple

fluorescent blue bowl trap (with yellow fluorescent & white bowls) in apple orchard—

soap in water breaks surface tension, bees drown

Insect pollinated fruit grown in Virginia

Study crops apple blueberry caneberry • raspberry• blackberry• black raspberry

mining beeon apple

Other insect pollinated fruit grown in Virginia

watermelon, musk melon pear, crab apple, serviceberry, quince (pome fruits) peach, plum, nectarine, apricot (stone fruits) pawpaw strawberry wineberry gooseberry, currant persimmon cranberry, huckleberry elderberry kiwi passion fruit prickly pear honey bee on prickly pear

Rosaceae (rose family) apple & crab apple, pear,

serviceberry, quince ★ caneberry (raspberry,

blackberry, black raspberry, wineberry) ★

peach, cherry, plum, nectarine, apricot★

strawberry

Other fruit families Cucurbitaceae (cucurbit):

watermelon, musk melon ★ Annonaceae (custard-apple):

pawpaw Grossulariaceae: gooseberry,

currant ★ Ebonaceae (ebony): persimmon Caprifoliaceae (honeysuckle):

elderberry Actinidiaceae (Chinese

gooseberry): kiwi Passifloraceae: passion flower Cactaceae (cactus): prickly pear

Ericaceae (heath family) blueberry, cranberry,

huckleberry ★

Crops with Virginia native relatives (shown in BLUE)—what pollinated these before honey bees were introduced?

★ Have more VA relatives not shown

Besides honey bees, what other bees are important crop pollinators in the mid-Atlantic region?

halictid (sweat) bees (various genera)

squash beesPeponapis pruinosaXenoglossa strenua

bumble beesBombus spp.

Osmia photos by T’ai Roulston, http://people.virginia.edu/~thr8z/Bee_Diversity/Blandy_Bee_Diversity.php

mason bees, Osmia spp.mining bees

Andrena spp.

Honey bees are eusocial, bumble bees are primitively eusocial, and most other bees are solitary

Bumble bee queens start a new colony in spring

Female solitary bees make and provision their nests alone

blue orchard bee

(solitary)

brood

honey pots

mining bee (solitary)

Some bees are active in cooler temperatures in spring or earlier in the morning than honey bees

early spring bees bumble bees, Bombus spp. mining bees, Andrena spp. blue orchard bees, Osmia spp. large carpenter bees, Xylocopa spp.

summertime early risers bumble bees, Bombus spp. squash bees, Xenoglossa strenua &Peponapis pruinosa large carpenter bees, Xylocopa spp.

some work later into the evening many, including bumble bees

Many native bees “buzz” pollinate—sonicating flowers improves pollination of crops like blueberry & tomato

Nightshade & heath families (tomato & blueberry, etc)

pollen is only released when sonicated, like sound is released from a tuning fork

pollen

style

stam

en

Percentages of bees visiting crop flowers (2008-2009 study)

★

★ Non-honey bees

Andrenid bees were the most common genus on apple and blueberry (27 species of Andrena in 70 total species on apple)

Andrena barbara was the most common

species on apple (1/4 of all specimens

collected).

vegetation, land cover classes (NLCD), soil (SSURGO) compare data freely available online versus field surveys

Next step: Compare bee species richness with landscape metrics

Management Implications: Practices that support native bee populations like protecting natural areas also benefit honey bees

Some of the best pollen & nectar sources are found in natural areas willow, tulip tree, locust, sourwood, sumac, wingstem,

goldenrod…

bees!!! on wingstem

Management Implications: Remind farmers to avoid chemical use when bees are active or reduce use all together

bumble & honey bees collecting corn pollen

You can’t move native bee nests—avoid spraying during the day Bees collect pollen from many sources (even plants that are wind-pollinated) Fungicides, though not intended for insects, harm bees

Management Implications: Native bees nest in the ground and in vegetation Protect natural areas or create

buffer zones to support bees leave brushy debris unless it may

harbor a pest species provide nesting sites such as

wood blocks, bundles of reed, or bare patches of earth

Many trees are fantastic sources of nectar and pollen stream buffers provide some of

the best habitat

Hedgerows also support other beneficial creatures spiders & predatory wasps

The following links are in a small hand-out--they include info on pollinator habitat & identification FRONT SIDE

Xerces Society: www.xerces.org Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms Using Farm Bill Programs for Pollinator Conservation

Pollinator Partnership: www.pollinator.org Selecting Plants for Pollinators: A Regional Guide for Farmers, Land Managers, and Gardeners in the Southeastern Mixed Forest Province

North American Pollinator Protection Campaign: www.nappc.org Reducing Risk to Pollinators from Pesticides

Bee IdentificationDiscover Life: www.discoverlife.org/mp/20q?search=Apoidea USGS, Sam Droege: www.slideshare.net/sdroege/slideshowsVA, T'ai Roulston: people.virginia.edu/~thr8z/Bee_Diversity/Blandy_Bee _Diversity.phpFlorida (good intro): chiron.valdosta.edu/jbpascar/Intro.htm Bug Guide: bugguide.net

BACK SIDE of HAND-OUT

National Biological Information Infrastructure: pollinators.nbii.gov/portal/community/Communities/Ecological_Topics/Pollinators/Pollinator_Species/Invertebrates/Bees_and_Wasps/

USDA Sustaining Native Bee Habitat For Crop Poll’n plants.usda.gov/pollinators/Agroforestry_Sustaining_Native_Bee_Habitat_for_Crop_Pollination.pdf

SARE’s Managing Alternative Pollinators (for beekeepers, growers, and conservationists) http://www.nraes.org/nra_map.html

Mid-AtlanticVA Fruit Page: http://www.virginiafruit.ento.vt.edu/VAFS-bees.html

Mid-Atlantic Apiculture Research& Extension Consortium: maarec.psu.edu

DE Dept of Agric: dda.delaware.gov/plantind/pollinator.shtml (several terrific guides on native bees, native plants, and farming for bees)

MD DNR: www.dnr.state.md.us/wildlife/wabees.asp (Wild Backyard--Bees)

PA & NJ: www.extension.org/mediawiki/files/1/15/NativeBees2009.pdf

Acknowledgements Richard Fell, Donald Mullins--Co-

Advisors

Douglas Pfeiffer, Lisa Kennedy, & T’ai Roulston—Committee Members

Virginia State government—grant support via the Virginia Cooperative Extension

All the farmers who so generously give access to their farms for this research

Sam Droege, US Geological Survey Bee Guru

Margie Adamson, Sydney Church, Clare Davidoski, & Jennifer Kilby--behind the scenes

VT Entomology Department

Thanks for use of photos from the following web sources http://www.holtanatomical.com/ http://appleparermuseum.com/Images/AppleLongSection

230.jpeg http://comenius.susqu.edu/bi/202/ARCHAEPLASTIDA/VIRI

DIPLANTAE/Flowering%20Plants/judd-photos/Frageria-flower-l-s.jpg 

http://www.biologie.uni-hamburg.de/b-online/vascular/ros.htm

http://www.inhs.uiuc.edu/~kenr/Photos/Prunus_flower.jpg  http://www.beeculture.com/content/pollination_handbook

/196.gif http://www.katsushikahokusai.org/Plum-Blossom-and-the-

Moon.jpg http://knowledge.allianz.com/nopi_downloads/images/C5_

plum_pox_resistant_plum_genetically_modified_GMO_q.jpg 

http://gemini.oscs.montana.edu/~mlavin/b436/labtotal.htm 

http://calphotos.berkeley.edu/imgs/128x192/0000_0000/0504/0300.jpeg 

http://www.naturehills.com/images/productImages/gooseberry_red_big.jpg

http://en.wikipedia.org/wiki/File:Asimina_triloba3.jpg

Hopefully I haven’t forgotten anyone. If I have or you want to share a better photo with me, please contact me at nladamson@gmail.com. Other photos are my own or acknowledged within the slides.

Questions?