Posts written by awpadmin

2016 Bee Abundance Analyses

Greetings apple growers!

We have some fun results to share. This report provides you a description of how we developed our model and a first year evaluation of your native bee community in your orchard. We are happy to find that we have very conclusive data just in our first year.

Why should you care about your native bee population?

A diverse native bee community not only supports plant diversity but it also has potential to drive pollination in apple.  Our 8 years of historical data show us that native bee abundance influences production of apple by increasing seed set (Figure 1; P = 0.008), while honey bee abundance has NO EFFECT (P= 0.36) on seed set, a similar result found in several other crop systems (Garibaldi et al, 2013).  Many studies have overwhelmingly determined that increased seed set influences uniformity of fruit shape (Figure 2), thus producing a higher proportion of Grade A fruits for market.

Using our historical data on pesticide use, surrounding natural habitat and the relationship between native bee abundance and seed set (figure 1; Park et al, 2015), we developed criteria for determining whether an orchard has enough native bees present during bloom time to provide full and efficient pollination.  Our original 15 minute ‘aerial net’ surveys determined that, if we catch an average of 9 native bees/15 min, the orchard is heavily dependent on native bees and would not be pollinator limited if honey bees were not present.

Validating and incorporating Smartphone data into our prediction model

In order to make connections between our historical data and the smartphone survey App data, we ran parallel 15-min ‘net’ surveys at multiple orchards and correlated native bee counts from ‘aerial net’ collections to the ‘smartphone App’ counts (figure 3).  Using the ‘equation’ of the slope of the trendline of that relationship, we calculated the expected ‘value’ of native bees that we would expect the app to record by inputting the significant value of 9 native bees/ 15 minutes (the significant historical net collection count) for X (see equation in figure 3). The result for the smartphone App count (Y) rounded to the nearest whole number was ‘4’ native bees per 5-minutes.  Therefore you need to count at least 4 native bees/5-min survey (on average) to conclude that you rely heavily on native bees (see lower orange line in figure 5).

IPM techniques: an easy step to take that benefits native bees

The smartphone data show us that growers who consider themselves ‘conventional’ have lower native bee averages than growers who consider themselves ‘IPM’ (See figure 4 below).  This suggests that a ‘conventional’ grower who is concerned about native bees could simply incorporate more IPM practices and potentially see an increase in native bee abundance over 3-5 years, that time range being the minimum time it takes native bees to respond to habitat enhancements.  It is important to note that this response is strong even considering the broad use of the term IPM that growers identify with.

Results for 2016 participants

The graph in Figure 5, below, highlights the 19 orchards that submitted at least 3 surveys this year; each bar is the ‘average’ count of native bees per 5-minutes across all surveys.  Seven orchards (M-S) have four or more native bees per 5-minutes. Using the predictive model that takes into account the year-to-year flux of native bee populations and uses GPS data, we can make recommendations.

For example, even though Orchard M (Figure 5) is surrounded by a large amount of natural habitat, they just barely meet the 4 native bees criteria. Given that they identify their pesticide program as ‘conventional’, we determine that they ride the edge of supporting a robust enough native bee population especially in bad weather years.  As a management recommendation we would suggest that they incorporate more IPM practices.

In the case of Orchard Q, we determine they have a robust native bee community but given that they are a conventional orchard we would recommend they either create more native bee habitat (forage & nesting sites) or tighten up their IPM practices to buffer years with low native bee populations, especially if they did not want to rent honey bees.

Orchards R and S easily meet all criteria and rely heavily on native bees for pollination insurance in the face of honey bee decline.

2016 participants will be receiving individualized feedback with in the next 24 hours.

Looking towards spring 2017 we are excited to add to this growing data set and make new connections to more growers.  Get your neighbor growers to use the app, compare results with them.  We want to share this with all New York apple growers.

Welcome to Summertime: The Data is In!

We truly appreciate all your participation this past spring in conducting bee surveys using the Smartphone app Survey tool. We gathered substantial data and learned a great deal about how to make the app even better for next year’s apple bloom.

Here at NEPP Headquarters we are busy analyzing all of your Spring survey data. Our participant summary shows that across 262 data entries we have data on approximately 30 orchards. These data points are spread across 4 states including 10 counties in NY, 2 counties in Connecticut and 1 county each in Maine and Massachusetts. The majority of users were orchard growers, researchers and teacher/students followed by orchard consultants and cooperative extension. Each user took data between 2 and 10 times. This is significant considering this was our first season. (See Summary Table)

NEPP Survey App Summary Table 2016

Summary of User Data                     
# of data points 262
# of Orchards ~30
# of counties in NY 10
# of counties total 14
# of States 4  (NY, MA, CT, ME)
User Type (Total # of Users = 22)
# backyard-naturalist 1
# commercial orchard grower 5
# orchard consultant 2
# cornell cooperative extension 2
# researcher 8
 # teacher-or-student 4
Orchard Type (Total # of Data Points = 260)
conventional 95
IPM 157
organic 7
backyard-garden 1
Average # of bees per orchard type                            
wild bees  honey bees
conventional 2.5  6.0
IPM 3.9  5.7
backyard-garden 6.0  10.0
organic 2.3  3.7

Your data shows that early bloom began between May 9th and 12th. And peak bloom ranged from the 17th to the 22nd of May. Compared to our historical data this was 2-4 days shorter than other years. This is not surprising considering sub-lethal damage caused by the April freeze in many areas.

As hoped, we see meaningful trends in regards to the effects of management technique and temperature on wild bee species vs honey bee abundance. IPM management techniques are significantly correlated with increased wild bee abundance across sites (Figure 1).

Figure 1. Comparing native bee abundances across IPM and Conventionally managed orchards.
figure1

As for bee foraging response to temperature, both honey bees and wild bees show increasing abundance with increasing temperatures. We see a slight tendency for honey bees to be a bit more dependent on warmer temperatures than the wild bee population (Figure 2).

Figure 2. How do native and honey bees respond to changing temperature?
figure2

For sites that we have previously sampled using standardized aerial netting, the wild bee abundance data looks comparable. As we dig further in to the data we will be looking at how your bee populations correlate with surrounding landscape and eventually be able make some regional and individual predictions about the ability of your wild native bee populations to provide full and efficient pollination.

It was very exciting for us that our app detected a 2016 trend showing increased honey bee abundance on specific sites we have been monitoring for several years. We learned that many growers had rented extra honey bees this season in order to compensate for the damage done to the apple blossoms during the April freeze. Orchard growers find that even if the bud damage is very low, apple blossoms can die more quickly when affected by a hard frost. Therefore, orchards that DO NOT normally rent honey bees, rented honey bees this year and orchards that normally DO rent honey bees rented even more hives than usual to ensure that they would get pollinated quickly if blossoms did not last more than a day or two. Being able to compare historical data with our 2016 NEPP App Survey data we found that this explains much of why we see higher-than-normal levels of honey bee abundance in many orchards this year.


Exciting news for next years apple bloom! We are making some important changes to the Survey app and will be providing additional support both in the App and on the website. This year we learned how important it is to get GPS points and bee data when it is NOT cloudy. While bees can be active during partly cloudy weather, fully cloudy weather distorted accurate recording of lat/long coordinates, which limits data analyses on certain survey submissions. This update along with supportive hints and increased functionality of temp and GPS and auto-fill systems will ensure increased user friendliness.

Thanks for your efforts! Keep your antennae perked for our next blog about the recently launched and wisely developed New York State Pollinator Protection Plan.

Comparing Native Bee vs Honey Bee Effectiveness

We are often asked by apple growers (and the general public) whether wild bees are effective apple pollinators in comparison to honey bees. This is not always an easy question to answer because measuring pollinator importance requires that we quantify two things: (1) pollinator abundance and (2) per-visit effectiveness.

Measuring Pollinator Importance

Pollinator abundance is an obvious correlate of pollinator importance – bees that are more common and visit apple flowers more frequently are likely to be more important pollinators than bees that are rare or visit apple flowers infrequently. Data we collect via the app will allow us to quantify pollinator abundance at your orchard and across the region. But pollinator abundance is only part of the equation because some pollinators may be more effective on a per-visit basis than others.

Per-visit effectiveness can be defined in a variety of ways but generally refers to how many pollen grains are deposited per flower visit or how many seeds are set per flower visit. Per-visit effectiveness will depend heavily on how a pollinator interacts with the floral morphology. A pollinator that walks around on the petals of the apple flower and takes nectar will not be as effective as a pollinator that lands on the reproductive parts of the flower and collects (and deposits) pollen.

We have spent a LOT of time trying to quantify per-visit effectiveness of various kinds of bees over the past few years. Our results suggest that, on a per-visit basis, wild bees are nearly four times more effective than honey bees. This means that an apple grower needs just 1/4 as many wild bees as honey bees to have the same level of pollination services in their apple orchard.

How This Survey Will Help Growers

First hand data that each apple grower submits to our NEPP data collection app will allow us to assess the level of pollination services provided by wild bees and honey bees at each eastern apple orchard. Based on the data you collect, we can then make specific data-driven recommendations back to you on whether or not (and at what level) to rent honey bees. These data will also allow us to monitor pollinator population levels across regions of the Northeast as well as over time.

So, please take a moment to visit the project website, download the app, and become familiar with the data collection protocols we have posted there. After you watch the video and scroll through photos of wild bees and honey bees you should be ready to start collecting data. Once you are familiar with the app, each data collection event should take no more than 10 minutes. Keep in mind that we need at least three observations at each site and more observations across a range of temperatures and days would also be extremely helpful.

We look forward to working with you to assess the pollination services at your orchard.

Where Do Bees Do Winter?


Winter has finally arrived in New York (and the rest of the Northeast). It is hard to imagine how bees – animals that love sun and warmth – are able to survive the cold northern hemisphere winter. Do they go south and spend the winter on a sunny beach in Florida? Or do they stick it out (like us humans) hunkered down at home?

The only bees that have the luxury of a winter vacation in Florida are the managed honey bees (Apis mellifera). Many of the migratory (mobile) bee colonies that are commercially managed in the US migrate to warmer places in the winter. This can be a strategy for reducing colony mortality over the winter months, which can be as high as 40% in some years.

In contrast, the wild (non-managed) bees that are so important to apple pollination need to stick it out up here, in chilly upstate NY. No Florida vacations for the native solitary and social bees that we described in our last blog post. These bees, in contrast to honey bees, enter an extended diapause over the winter. Bumble bee queens, for example, mate in the Fall and then find a sheltered cavity in a wood pile, old stone wall, or mouse burrow to wait out the winter months. Bumblebee queens are enormous, with extensive fat reserves to carry them through the winter and to fuel their early spring nest searching.

Most solitary, ground-nesting bees (such as Andrena, Halictus, Agapostemon, Lasioglossum, and Colletes) are in their underground nests in a similar state of diapause. Their metabolic rates have dropped and they are in a state of suspended animation within the underground brood cells produced by their mother.

Stem and cavity nesting bees (such as mason bees and leaf cutter bees; Osmia and Megachile) are in a similar state of suspended animation (diapause), but their nests are above ground and hence experience even more dramatic shifts in temperature than those overwintering in the ground. Wood-boring carpenter bees (such as Xylocopa) remain within their mother’s nest and hunker down with their siblings to pass the cold winter months.

As an apple grower, you can rest assured that, even as the cold winds of February blow, the hard-working solitary bees are still here, spending the winter literally under our noses. Overwintering as an adult means that they are ready to emerge as soon as the weather warms up and the early spring flowers start to bloom. Think of these bees as the Punxsutawney Phils of the insect world – ready to emerge from the ground when conditions look right. But they still have a few more months of restful diapause before spring arrives in this part of the world.

The Secret Life of Bees

In addition to providing tools for monitoring wild bee populations in apple orchards, the NEPP seeks to educate orchardists, backyard naturalists and the public about these economically and ecologically important wild pollinators.  Who are they? How do they thrive? How can we help?

Many Kinds of Bees

Since 2008 we have learned a great deal about the biology, diversity and ecology of the wild bees that contribute to NYS apple production. The 120 identified species of bees visiting apple blossoms in New York represent one quarter of the approximately 415 species of bees that occur in New York. In terms of nesting biology, the apple bee fauna is dominated by ground-nesting bees (67% of the species), below-ground: cavity-nesting bees (11% of the species), stem-nesting species (10%) and a small number of wood nesters (carpenter bees).  By the way, the social honey bee is just one of the 120 species.

Solitary Bees and Social Bees

In terms of social behavior, the apple bee fauna is dominated by solitary bees. Bees are termed solitary when each female constructs her own nest, gathers and stores her own pollen/nectar provisions, and guards her own nest against parasites and predators. She is highly dependent on the proximity of nesting substrates and floral resources. Also, solitary bees tend to be active for a relatively short period of time, whereas social bees persist throughout the spring, summer and fall. Therefore, Spring solitary bees tend to be more highly specialized (and dependent) on early spring flowering trees (such as apple) than their social relatives, potentially making them more effective pollinators.

Attracting Native Bees

So, what does this mean for apple growers who want to maintain a healthy local, wild bee fauna? First, apple growers should provide a diversity of nesting materials for wild bees in and around their orchards. Ground nesters being the most abundant species in apple orchards will benefit from the availability of disturbed, loose soil (‘bee beds’). We recommend tilling a small area along the edge of the orchard to a depth of 10-12 inches in order to provide loose soil for ground-nesting bees. Carpenter bees can benefit from fallen trees, and weathered lumber in and around the orchard. Bumblebees will likely benefit from stone walls, mammal burrows, and brush piles. Stem-nesters, such as mason bees utilize hollow plant stems & branches as well as wooden blocks and cardboard tubes of the right diameter which can be purchased commercially.

Learn More

For more information about the diversity of wild bees in NY apple orchards, see our published guide “Wild Pollinators of Eastern Apple Orchards” available at http://entomology.cals.cornell.edu/extension/wild-pollinators.