Durability of life of bees in greenhouses

Durability of life of bees in greenhouses

It is considered that the microclimate of greenhouses has a negative effect on bees. In order to weaken the influence of the greenhouse microclimate on bees, special rooms for hives were set up, and casings were used. Even different designs of hothouse hives have been proposed.

To convince colleagues of the futility of further searches for bee colonies of isolators from a greenhouse microclimate and special hives, we consider it necessary to briefly discuss the various proposals rejected by practice. So, a teeplek was proposed for year-round keeping of bees. Teplyak was placed outside the greenhouse. It was built of 5-cm boards, the roof is covered with iron. To switch the summer of bees into a greenhouse or to freedom, tapholes were opened and closed with latches.

Simultaneously, the beekeeper constructed a special beehive with 2 bottoms. The hive was placed in a tight casing with a lid. Bottom space was divided by a partition into 2 chambers. The arrival of fresh air from the will was regulated by a latch in the sleeve. The regime in the chamber depended on the air temperature in and outside the greenhouse. To eliminate the warm air coming through the gap for the passage of the bees into the greenhouse, an exhaust pipe with a latch was installed.

The time has passed, and the scientists of the strong point for pollination of closed ground cultures offered thermal insulating boxes for bees, which also did not go into production. It would seem that everything is clear. The reasons for the weakening of the bees are different, but deliberate prejudice continued to push the discovery of the long-forgotten. The beekeeper again proposes, in order to mitigate the adverse effects of the greenhouse microclimate, to place the hive in the greenhouse in a chamber that has a connection with the greenhouse and the external environment. And the results? The bees continue to “wear out”,

and it “replaces” them in the greenhouses only once in May.

To isolate the bees from the greenhouse microclimate, the agronomist suggested carrying bee colonies out of the greenhouses and placing them in the wild so that the hives were placed against the former place. Through the upper duct the bees had access to the greenhouse, through the lower one – to freedom. However, the work to remove and transfer bees to greenhouses has proved to be time consuming. To facilitate it, the hives were installed on a frame specially made of angled iron. On this frame, through the opening transom, the hives are moved to the will or back to the greenhouse.

According to studies, the average mass of bees raised in greenhouse conditions was 95.66 mg. Without beans, these bees died within 39-44 hours. The bees raised in the apiary had a mass of 108.62 mg and died in the absence of food after 47-52 hours, that is, they were more resilient. The bees from the hives standing outside the greenhouses collected more honey.

Before deciding where to keep hothouse bees in summer, it is necessary to know how the microclimate of the greenhouse acts on the mode of the nest of the bee family and on the work of the bees by pollination of the cucumbers.

It is known that a bee family with brood maintains a temperature within the nest of 35-36 њ C. Researcher W. Hess (1926) artificially heated the temperature in the hive up to 40 њ G, but the temperature in the nest remained constant all the time, that is, did not exceed 36 њ C. In the literature there is a report (Dungeym, 1933) that a short-term increase in the temperature of the hive to 42.2 њ C did not cause much harm to the brood.

According to the data, when the bees were transported in beehives with closed flaps and free upper ventilation in the nests of bee families, the temperature rose to 40 њ C, but no visible disturbances were noted.

From what has been said it is clear that bees are capable of thermoregulation. However, at a prolonged temperature above 37 њ C the brood perishes, and the bees cease their work.

What temperature is acceptable for greenhouses? The optimum temperature for growing cucumbers is usually considered 23-25 ​​њ C. Greenhouse workers strictly follow this. They know that with an increase in the corresponding temperature, plants are stretched and pampered, become brittle and break easily. In addition, elevated temperatures favor the appearance and development of pests and diseases of cucumbers. With increased air temperature, pollen becomes sterile, that is, transferred to female generative organs, does not germinate and does not form ovaries. Despite the active years of bees on flowers in the morning cool, the ovary withers under such conditions. Therefore, at a temperature in the greenhouses over the optimal take measures to reduce it (cooling greenhouses): sprayed beds and paths with water,

In summer, in sunny weather, it is permissible to increase the air temperature in the greenhouse to 30-32 њ C.

What is actually the temperature in the summer hot season in the greenhouses and outside it, that is, at the southwestern corner of the hothouse, where the hive is transported in the summer? If you take hot summer days (usually at the end of July), when there is sometimes 28-29 њ C in the shade, the temperature in the hives outside the greenhouses is usually 0.4 to 1 њ C higher than in the greenhouses. This is because the hives standing in the greenhouses are obscured by the whitewashing of the roof, and the beams of the sun are falling on the hives taken from the greenhouses.

To verify the comparison of the quality of bees, deduced in bee families, which were used for many years only in greenhouses, we conducted the following experiment. Groups of 4 strong and 2 weak families of local bees were selected, which were used in the wild and in greenhouses. To all strong families on May 26, there were 2 frames with a honeycomb, and weak ones – on 1 frame of light land. Of all the families on June 17, of the framed frames, there were taken 10 out of the cells of bees. When weighing them, it turned out that the average weight of bees in all the strong families was 112 mg, in weak families at will – 107 mg, in weak hothouses – 106 mg. These data indicate that in more powerful families more viable bees are deduced, regardless of where they were kept – in the wild or in the greenhouses.

By means of a mass and single bee sweep, the duration of their life in the greenhouses was checked. The bees that were born in the first days of March, on average lived 29 days with a maximum life expectancy of individual bees up to 51 days.

With the flight of bees to the wild and the arrival of fresh pollen, bee colonies are growing rapidly.

Many are inclined to think that the increased humidity in the greenhouse has a negative effect on bees. Analysis of literature data on the nest’s moisture regime and its effect on bees showed their extreme inconsistency. According to studies, the humidity in the bee nest depends on the availability of honey. In the absence of honey, the air humidity in the streets between the brood varies from 76.6 to 91%. With a significant amount of honey, humidity dropped to 54-66%. Reduction of air humidity during honey collection explains the need for bees to accelerate the evaporation of excess nectar moisture, ie, this decrease in humidity in the nest is forced, and it is done by bees. Consequently, the humidity regime in cucumber greenhouses for brood rearing is favorable, and it is not necessary to reduce it artificially.

Some experts believed that bees, adapted to a warm, humid climate, would be better in greenhouses. To test this, the Abkhazian (Sukhumi) bees were tested at the vegetable station and in the subsidiary farm. Advantages in their development and work in greenhouses in comparison with other breeds of bees have not been established.

Some experts doubt whether the excess of carbon dioxide in the greenhouses affects negatively the bees. It is known that in ordinary air carbon dioxide contains 0.03%. In greenhouses in the period of intensive development of plants that have a well developed vegetative mass, there is almost no carbon dioxide in the midday, most illuminated hours, which weakens photosynthesis and reduces the yield, especially in gravel greenhouses.

Practice has established that with the artificial replenishment of carbon dioxide air, the yield is increased by 25-30%. Therefore, in greenhouses, plants are fed with carbon dioxide, which is carried in cartridges with a capacity of 20 kg, which are installed in the center of the greenhouse. The content of 1 bottle is sufficient for one-time feeding of a greenhouse with an area of ​​1000 m2. Recently, solid carbon dioxide (dry ice) has become very popular. It is crushed and hung in drawers along the central path. In some farms flue gas is used to feed plants. In all cases, only for a short time the carbon dioxide content in the greenhouse reaches 1%, but this concentration does not affect the behavior and work of the bees in the greenhouse.

From what has been said, it can be seen that both the gas composition of air and the overall microclimate in greenhouses do not have a significant negative effect on bees.

As our long-term observations have shown, the main reason weakening bee colonies in greenhouses is the size of the greenhouses and the translucency of the roof. Bees, rushing to the light, fight against the glass, and in the cold time they are glued to the wet windows and freezes. Many bees fly out of the greenhouses through insignificant cracks in the roof and are lost.

Therefore, it will be more correct to talk not about microclimate in greenhouses, but about conditions, about the ability to find the true causes of bee loss. Regardless of where the hive is placed, in a greenhouse or outside it, bees must work in greenhouses. The duty of the beekeeper is to bring the conditions of the greenhouses closer to the normal ones and to exclude their harmful effects on the bees.

Over time, the bees develop a conditioned reflex to the spatial limitation of the greenhouses. Within a few days after the introduction of bee colonies into the greenhouse, the bees are much less beaten against the glass. Even on the first fly of the bees in the greenhouses, the observant masters of the greenhouse unerringly determine whether these bees worked or not in the greenhouse last season. Previously, bees that did not work in the greenhouse fly violently and strongly beat against the glass. The bees, already working in the greenhouse, fly more calmly and carefully.

As it was said above, the roof of the greenhouses and a small opening for the bees to fly to the will to some extent keep the bees from pollinating the greenhouse culture. Bees that are outside the greenhouses, significantly reduce, and in the case of significant and prolonged honey harvest at large, they completely stop working in greenhouses. This is confirmed by the practice of many greenhouses and numerous observations.

Therefore, in order to obtain high and stable yields of cucumbers and other crops, it is not necessary to expose bees outside the greenhouses, in the central regions and in the north-west of the country.

Partial death of bees in greenhouses should be recognized as a production cost, which can be compensated without harm by favorable (thermal) conditions for the development of families and proper care.

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Durability of life of bees in greenhouses