Growing the bees to grow the farm

The project had different types of producer engagement and consequently produced different types of results. The proof of concept of collecting wild swarms in AZ of Africanized origin and conerting them to bees suitable for agricultural is a type of "production project". The total production was deeply affected by the drought, however, the actual procedure and success of the strategy was proved successful and worth of continuing from a practical sense.

The colonies used in this part of the project originated as swarms caught in pheromone baited swarm boxes in Tucson, AZ.  These colonies were previously eliminated but the owner of the company decided to start an apiary for future commercial use. A subsample of the colonies was tested using PCR (mtDNA) and were confirmed, as expected for wild caught bees in the area, to be Africanized.  

The expected swarm catch per year, based on previous records, was expected to be in the 100 to 150 swarms, however, the absolute catch was much smaller due to drought conditions. Only, about 30 new swarms were added in 2020 and 2021 to the already established colonies, a clear departure in bee population from previous years. In 2021 – 2022 (Winter-Spring 2022) another 20 were added. As of this report, the AZ beekeeper that owns the colonies is negotiating 3 different sale requests for his colonies, confirming that there is both a need and local clientele for the bees reared from wild caught AHB swarms.

As of now, the AZ beekeeper that owns the colonies is negotiating 3 different sale requests for his colonies, confirming that there is both a need and clientele for the bees reared from wild caught AHB swarms. We had 10 individual requests for assistance with supplemental feeding both in HI and AZ.

The extreme weather (drought and unexpected cold spells) and uncharactersitc timing of the native plant blooming forced us to change our original goals and modify what we could or should do with nutritional supplements for bees under climatic stress. The result was a deeper understanding and field tesitng of modified dietary supplements for bees. The need to provide intense assistance to the colonies also showed the fragility of the environment in which these bees are kept and the changes that beekeepers need to consider before they embark in beekeeping projects in these areas under the current conditions. 

The summary results will be presented below according to the Objective categories

Objective 1 - Improve the health of colonies that will provide pollination services

Improving the health of colonies via management and supplemental feeding was one of the goals of the project. This objective had to be modified due to extreme drought conditions. To survive weather stresses all colonies needed supplemental food and water. Consequently, we concentrated on collecting data on the nutritional needs of the colonies under these environmental stresses and added aspects of thermal regulation to the report. In the end these extreme conditions provided valuable information on emergency care for managed pollinators during extreme drought and unseasonal cold spells.

The following are elements of our strategy and management modifications we made based on field conditions. Originally we employed a  a liquid diet and a more solid carbohydrate diet depending on environmental conditions. The colonies were fed using internal feeders, which meant they had to be opened to pour the liquid. This procedure was difficult due to the robbing activity that took place between colonies as they detected a sugary liquid in a dearth period. The intensity of aggressive interactions between colonies increased as we progressed through the bee yard feeding the colonies. Over time we decided to only use liquid diet to feed those colonies that were not consuming the sugary supplement, generally they were the smaller colonies, and this change made a real difference in field procedures and successful colony management.

During the second summer we began to use a home-made diet that had variables amounts of sugar and oil, but also protein. The “patty” recipe was provided by Emanuel Miranda, a collaborator from Costa Rica, where AHB are common. We successfully modified the patty over the course of the project to create a summer patty and a winter patty.

Summary findings:

• Carbohydrates were needed throughout the study period
• We selected a liquid diet of sugar syrup in 1:1, not corn syrup, for use under extremely high ambient temperatures. Fresh water was provided as well.
• We used a homemade – relatively solid sugar supplement (a mix with pollen, oil, and amino acids = called here “sugar block”) when temperatures declined beyond normal for the site, particularly useful when they dropped to freezing or below freezing at night.

The quantities presented in the table below correspond to amounts per week per colony of supplemental food

Our Arizona field data shows that due to the present conditions, with severe droughts and cold spells, the lower elevation desert areas near Tucson are not suitable for the traditional stationary beekeeping due to resource scarcity. We observed how several local beekeepers repeatedly lost their bees during the grueling summers and during the cold spells. Unlike what is reported by older beekeepers from the area, the bees now needed supplemental food during most of the year when stationary on the site. This change in resource abundance and increased climatic stresses resulted in large scale beekeeping losses in AZ, and to first time ever emergency declaration by the USDA which allowed beekeepers in the state to present claims due to environmental conditions.

We know that these areas in AZ have been used in the past by migratory beekeepers to overwinter colonies near California. Many of these migratory colonies come with enough honey reserves they have gathered while working on pollination in other regions of the country. We believe, based on our field observations, that if the beekeepers leave enough honey on the colonies, they will not need the supplemental carbohydrates we provided, and the site is still suitable to use as “short-term holding yards” before transporting the bees to almond pollination sites in CA. However, we noticed that several beekeepers attempted to reduce management time and provided large amounts of water and or syrup to their bees, but they did not provide follow up visits and consequently were unable to remedy situations that resulted in bee death during their absence. For example, feeding with an internal feeder using a liquid diet in the winter can result in the food freezing and the bees starving, especially if the equipment has holes and/or colony is too small and can’t keep the edge of the box warm enough. The AZ winter is relatively mild compared to more northern regions, however unusual cold spells and even snowstorms can occur.

This last spring 2023, was a record blooming period, and the colonies grew faster and stronger. The number of swarms caught by our beekeeper collaborator has already surpassed what he collected the previous years in a few months. This welcomed change is still tempered by the knowledge that conditions in AZ , and in the west as a whole are not stable, especially when it comes to rainfall and snow reservoirs on the mountains.

Access to water is needed year-round, however, local beekeepers tend to think it’s more of a summer need, and the distance that bees need to fly to water can cause large physiological stress to forager bees and reduce their longevity. Adding water in large drums is common practice in the summer but without a shade cover the water quickly evaporates and bees are compromised. The open field pollination that was common in the farm areas near Tucson and Phoenix can now be potentially stressful to bees because of the soaring ambient temperatures, lack of resources from native or weedy species when the crop has ended, and reduced water sources. These conditions resulted in some beekeepers lost colonies as the wax inside the colonies melted while in the field.

The supplemental feeding allowed the colonies to continue to produce brood in the fall and winter, thus the colonies were able to pick up and grow faster when spring arrived. This trend has also been noted in Hawaii’s colonies, which are often not fed during the very mild winter in Hawaii, but when provided with supplemental food, they tend to react to incoming natural resources much faster than control colonies (Ph.D. thesis by Zhening Zhang, University of Hawaii at Manoa). A version of this new patty is being tested in Hawaii, where climate change has also affected resource availability and where prolonged rains can reduce foraging time. Some of our Hawaii collaborators are interested in the new diet, some still resist the change and don't want to use supplemental food.

Springtime arrives relatively early in AZ and often there is enough pollen to get a colony in growth mode. However, due to variable winter rains and increasing ambient temperatures in the summer the survival, percent cover, and productivity of some Sonoran Desert plant species is changing (https://www.nps.gov/articles/plant-responses-to-climate-change-in-the-sonoran-desert.htm) and the expected resource abundance may not be what it used to be. This can be especially true for annual herbaceous plants, which show a strong response to winter precipitation, but also for some other species that suffer under the higher ambient temperatures in the summer.

Data of colony health based on this project is being currently analyzed. The Varroa mite levels were consistently below the require 3 to 5% that is recommended for treatment. This is not unusual due to the fact that the colonies were Africanized. We will analyze bees collected in 2023 for DWV types.

The data on environmental temperature effects and the management strategies we implemented to alleviate the field conditions is being worked into a document for publication. The AZ crop production fields are devoid of shade, and even the Sonoran Desert landscape has limited large trees that grow tall enough to provide much shade for colonies. Through the use of in-hive temperature and relative humidity sensors we learned a great deal about the bees coping strategies and how to reduce their physiological stress in the field. This data will be prepared as both an extension paper and a scientific journal and will be shared with WSARE upon completion and submission respectively.

Objective 2 – Incorporate colonies that would be destroyed into the pool of manageable honey bee colonies.

Objective 2 focused on the management strategies that are to be followed to re-queen Africanized bees with European bees. This issue has been reported problematic in southern states where the EHB mixed frequently with feral bees and the character of a colony changes.

There are online recommendations on how to re-queen that range from naïve to unrealistic and could mislead novice beekeepers.  Here we provide a summary of common problems and potential solutions based on our experience.

• Re-queening Africanized Honeybee Colonies

Difficulties of re-queening AHB bees are usually linked to 3 main issues:

1. The colony is very large and has become highly defensive

A large colony, whether is AHB or EHB is likely to be more defensive and can be difficult to manipulate. Contrary to what the literature says, we have data that shows that AHB colonies that have access to resources and are provided sufficient hive space do not swarm that often, become very large and can respond with great defensive strength. The larger the colony the more difficult will be to find the queen and/or split the colony in two.

2. The worker bees reject the new queen

Queen rejection can happen in both European and Africanized colonies, although it seems to be more common in AHB that are being re-queened with European stock. Patience and time seem to be critical in positive results when re-queening AHB. Unlike EHB where a beekeeper can remove a queen and in the same day add a caged queen for the bees, AHB need to be given about 7 days of being queenless and the beekeeper needs to be careful to remove over the first 3 or 4 days any queen cell that the worker bees have created. Once that is done, a caged queen can be inserted. It is preferable that initially the candy is blocked at first, so that the workers can only interact with the queen from outside, and by the next day the candy can be exposed so the bees can release the queen. The total procedure from queen removal to new queen inserted takes about 10 days. However, the results from our field trials using queens from 2 sources, Hawaii and New Mexico, were over 90 % acceptance and some our EHB queens lived for over a year in their new colonies

          3. The worker bees replace the new queen within a month or two

This type of event can happen with both EHB and AHB and is hard to predict when it will happen. Introducing a marked queen helps detect the event, but also working the colonies often enough to detect a break in the laying is good indicator of a change. In our study, about 15 % of the queens were replaced in the first 2 months, however, the daughters of those queens showed strong EHB tendencies even though they were open mated with large numbers of AHB drones in the apiaries. Marking the original queen also helps to detect to track the “personality” changes that take place when a queen superseder occurs.

We have now produced 2 documents that relate to this objective: the first is a handout illustrating the diversity of nesting sites that are used by Africanized bees in AZ and promoting the use of swarms traps in combination with artificial bee pheromones to lure the bees into these boxes, the second handout outlines guidelines for re-queening aggressive colonies. The AHB can pose serious problems due to its defensive behaviors, we tested re-queening with 2 sets of HI queens and I set of NM queens. The handout is based on those field experiences which had large success rate.

Our re-queening success, that is the number of European queens accepted by a hive full of Africanized honeybee workers was influenced by the number of days that spanned between removing the original queen (and the emergency queen cells that the workers created), and the introduction of the new caged queen. When the wait was only 5 days only 50% of the queens were accepted. When the wait was 7 days, 80% of introduced queens were accepted by the worker bees. The idea that an Africanized honeybee colony needs to be "hopelessly queen less" before they accept a foreign queen seems to be true.  

In our handout we also indicated that the placement site for a new caged queen differs from the regular placement for European queens. When we attempted to introduce the queen directly to the brood area the cage was immediately swarmed and the workers were aggressive towards the new queen. When the queen cage was attached to an "outer frame" fewer bees approached the queen and their response not aggressive. Although the nurse bees which could provide the best food for the queen are in concentrated near the brood, the defensive reaction was too strong. Queens placed in the periphery were fed and survived the introduction.

Re-queening can only be partially assessed based on the immediate acceptance of the introduced queen. It is important to understand how willing the worker bees are to keep that queen or if they use her eggs to quickly replace her with a queen mated locally, which in this case means a queen with local genetics, and most likely Africanized. Re-queening in early fall in AZ normally meant that colonies would be large, the new queen would not need to go out and mate, since she is already fertilized. Unfortunately, when we tested this we experienced much colder drier winters and suboptimal spring conditions. Consequently, the long term survival assessment of the queens was influenced by those factors. However, when the mortality among the colonies with local stock and the new queens is compared, there was not a statistical difference. Basically it was a hard period for all colonies.

In summary, Objective 2 in our study confirms that wild swarms in AZ will be of Africanized origin but it also shows that it is possible to take wild swarms from areas where AHB are dominant in the feral population and use them for agricultural and or honey production. However, the total number of swarms under these conditions was severely reduced during our study, this in combination with the extreme climatic events, made if difficult to grow the numbers of colonies as had been expected.

Objective 3 – Collect data on the genetics and possible mite resistance or variable levels of viral diseases in the wild caught bees in AZ

Genetic Origin: The colonies collected as swarms in AZ all tested as AHB using mtDNA, so their queens had Africanized genes in them. To further understand the genetic admixture of European Honeybees and Africanized honeybees we began a collaboration with Dr. Brock Harpur from the University of Purdue. We completed a full genome analysis of 25 colonies from AZ and added some from NM. The results suggest that the AZ colonies have a large proportion of Africanized alleles (A), and the rest is a balanced mix of C and M lineages. The NM bees have a much lower degree of Africanization (below10%, except for one colony).

In addition to the lineages and admixture, we correlated our field aggression scores for each colony to SNPs for defensiveness. The preliminary results show that colonies we ranked in the field as very defensive seem to correspond to those a % SNPs higher than 60%. This type of correspondence between field collected observations and molecular results is rare, and in this case our data will greatly contribute to the modern definition of what constitutes Africanization and how to characterize and regulate AHB in the US. We are working on a collaborative publication based on these results.

Mite Resistance: AHB exhibit great resistance to mite infestation and generally can survive without treatment. This is in contrast to their European counterparts that suffer greatly with the Varroa mite and the associated viruses. We have begun to examine behavioral mechanisms of mite resistance that appear to be present in the managed bee populations on Oahu, HI. We will continue to examine this interesting phenomenon and are planning to expand our work to compare and contrast the behaviors exhibited by the AHB in AZ.