The integration of agricultural activities with those of beekeeping and meliponiculture is beneficial and possible. Addressed as an important component of sustainability, this assimilation demands measures to mitigate the risks of agricultural practices on bees. On a large scale, most crops of agricultural interest require the use of pesticides to control their antagonists (such as pests, diseases and weeds), and good agricultural practice measures in the application of these products are fundamental in the adoption of Integrated Crop Management. Pests (MIP).
Phytosanitary treatments should only be carried out when really necessary, strictly following the instructions for use, for example, without exceeding the recommended dosage and with products authorized for the crop and respecting the climatic conditions in the applications. These are basic measures to minimize risks, alongside qualified technical assistance.
Knowing the main pollinators to conserve, the selective products and the pattern of use based on the behavior of these insects are essential measures for choices that minimize the risks of contamination of bees in the field.
Pollination is an entomological service that occurs in ecosystems, whether agricultural or natural. Contrary to popular belief, the pollinator visits plants looking for floral resources for food and not with the intention of pollinating flowers. Hence the difficulty of measuring the values of these ecosystem services in Entomology.
Due to the degree of dependence, some plants do not depend on external agents, such as bees, for the fertilization of their eggs to occur and carry out self-pollination (for example: rice, beans, sorghum and wheat), or in cultivation not even the flowers have meaning (garlic, sugar cane, cassava and tobacco). Other crops have a very restricted dependence on pollinators (cotton, coffee, castor and soy).
On the other hand, cross-pollination provides genetic variability of the plant species, diversifying plant genomes, some of which are more vigorous and productive. The cases of the chestnut tree, the guarana tree, the guava tree and the passion fruit tree are illustrative in this aspect.
For a large majority of plant species, pollinators are essential, as without them many would not be able to reproduce and, consequently, it would not be possible to produce fruits, seeds, almonds or chestnuts, which are used on a large scale by human society; in addition, they contribute to the maintenance of native vegetation and the increase in the production of various crops. Thus, plants attract pollinators by offering rewards such as pollen, nectar, oils, resins, colors and odors, which in turn attract a variety of floral visitors.
It is known that the most efficient pollinators par excellence are insects, especially farmed or wild bees. Among the genera of bees that stand out as crop pollinators are the Centris, from solitary oil-collecting bees, the xylocopa, which are also solitary bees known as carpenter bees because they nest in wood and are very important for passion fruit and Brazil nut trees. The gender Bombus It also stands out with the bumblebees, also very important for passion fruit cultivation, in turn the group of stingless social bee genera (meliponines and even Trigona) are useful for the pollination of various plants.
The best-known bee, cited and used in monocultures, belongs to the domesticated species Apis mellifera (Hymenoptera: Apidae), commonly called Africanized or honey bee, as it has a wide geographic distribution. It is a generalist, foraging a huge amount of plants and crops, with high intensity, visiting several flowers due to its great nutritional need to maintain the colony. Furthermore, it is widely managed for the exploitation of its products such as honey, royal jelly, propolis, bee pollen and wax. They are also commonly used in migratory beekeeping mobility, with the aim of pollinating crops at the height of their flowering so that maximum productivity (possibly quality) of the crop and collection of bee products can be achieved. In turn, meliponines tend to be managed more artisanally and are less scientifically known, which does not reduce the service they provide.
The first point is to distinguish causes of potential bee deaths, such as the importance of clearly separating incidental and accidental causes from deliberate actions. Furthermore, understand that Hive Collapse Disorder (CCD) has supposed multiple causes, occurring in cyclical periods in recent centuries, predominantly in the Northern Hemisphere and not exclusively caused by pesticides.
The proximity of bees to agricultural crops makes them exposed to different phytosanitary products used to protect crops, which causes great concern about the health of these insects. Thus, given the integration of agriculture with beekeeping and meliponiculture, measures to mitigate pesticide risks for such pollinators are necessary.
The full adoption of MIP in crops is the first step in this reconciliation. The use of monitoring pests and beneficial organisms as a decision-making instrument duly associated with the application of cultural control methods, plant resistance, biological or natural control, regulatory resources, among others, eliminates the need to use pesticides in an emergency to prevent extrapolation of the level of economic damage.
Knowing the list of selective products for these pollinators to make the right choices is key. Also, having prior knowledge of the list of the main pollinators that visit the crop in which such applications are intended, as well as their foraging behavior in the crop, is of great importance for conservation actions.
In the operational part, avoid applications directly to bees visiting crop fields, for example after early morning until late afternoon, especially during the crop flowering period, as this is when they are most attractive to bees, seeking to carry out these treatments. very early in the morning or close to dusk or at night, always following the recommendations for use in the phytosanitary product leaflets. Simply put, avoid applying pesticides between 8 am and 16 pm, which also has some practical significance in the effectiveness of applications, due to the frequent intense winds and gusts, higher temperatures and low air humidity.
The best option is to apply phytosanitary products when there are no bees or apiaries close to the crops, but this is often not possible. Therefore, if viable, if there are colonies located on crops during flowering, application is not recommended until they are removed. Alternatively, it is recommended to protect the colonies at the time of application, closing the entrance or exit gap for adult bees from the hive.
To optimize the validity, applicability and functionality of these measures, there is a notable need for frequent and professional dialogue between neighboring beekeepers and farmers and their managers, or even between pollination service providers and those responsible for surrounding crops. The vast majority of bees forage within a radius of two to three kilometers from the hive.
The composition of foraging sites with other plants that allow for a larger, more diverse and more attractive bee flora than cultivation is also recommended, as an alternative to increasing the diversity of habitats and plants in the surrounding area where bees can collect floral resources, these locations where there were no applications of phytosanitary products. For this purpose, plants have been suggested such as: assa-peixe, vassourão-branco, astrapeia-rosa, dwarf eucalyptus-with-red-flowers, cambará-lixa, paineira-bombax, resedá-branco, resedá-rosa, ipê- garden, among others.
It is also appropriate to conserve native vegetation close to agricultural cultivation areas, which provide habitats with flowers for pollinators as a more attractive and efficient source of resources than the agricultural crop itself. Thus, the number of visits to crops receiving applications will decrease and the risks of contamination will be lower.
Another point to be observed is respect for safety ranges for applications (distance between cultivation and preservation or conservation areas), in accordance with the concepts of good agricultural practices and the relevant legislation for each location or product leaflet. It is always recommended to periodically carry out maintenance on land spraying equipment, as well as follow the recommended dosages, with spray volume and droplet size for each product to be applied; thus, maximum effectiveness in pest control will be obtained, losses due to drift will be avoided and consequently the contamination of pollinators will be prevented, contributing to their conservation.
As for recommendations for aerial applications, which are no more harmful than terrestrial applications, it is proposed not to apply at a distance of less than 300 meters from areas of natural vegetation and neighboring agricultural crops in the flowering phase and visited by bees. It is recommended that before applications, beekeepers located within a radius of up to six kilometers must be notified at least 48 hours in advance, so that they can protect their hives, and it is recommended that applications be made at a height of three to five meters flying height over the crop to be sprayed. It is noteworthy that anonymous beekeepers or those who place their hives clandestinely in unauthorized locations end up being subject to surprising problems of bee or hive deaths.
The application volume must be at least 50 liters of syrup per hectare, if feasible for the success of the phytosanitary treatment, and the climatic conditions must be respected according to the phytosanitary product registration leaflets, trying to apply when the wind speed is between 3km/h and 7km/h, the temperature is below 30ºC with relative humidity above 55% and with fine and medium droplets, thus aiming to reduce losses due to drift and evaporation as much as possible and ensuring efficient pest control. Some states of the Federation have their own standards for aerial spraying, so attention must be paid when applying.
Contemporaneously, in an agriculture 4.0 environment, where data collected, transmitted and processed in real time improves productivity and sustainability in the field, it is necessary to develop products, processes and services that use georeferencing (GIS/GPS) of hives, mapping and intercommunication applications, maps and warning systems to warn of imminent risks.
In short, we note the evident importance of permanent dialogue between neighboring beekeepers and farmers (or their managers) for risk management, with a view to minimizing bee mortality problems and avoiding interpersonal, legal or business conflicts.
Ellen P. Souza and Paulo E. Degrande, Univ. Federal District of Grande Dourados (UFGD)
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