Chemical toxicosis of bees

Chemical toxicosis of bees

Chemical toxicosis is an infectious disease caused by the poisoning of bees by poison-insecticides used to control insects harmful to agriculture and forestry. Causes of the disease. Chemical poisons, applied against harmful insects (insecticides), are divided into contact, or poisons of external action, and intestinal, or poisons of internal action.

Poisons of contact action poison insects when they come into contact with their body. They are intended for insects that have soft, soft and moist covers, for example, larvae of flies, naked caterpillars, aphids, chervens, leaf-blocks. Contact insecticides include kerosene emulsion, anabasine sulfate, nicotine sulfate, herbicides, tobacco broth, fuel oil, phenol, mineral oil emulsions, calc-sulfur broth, Bordeaux liquid. These poisons are less dangerous for bees than intestinal insecticides.

The most dangerous for bees are intestinal insecticides: inorganic (arsenic,

fluorine, barium), chlororganic (DDT, hexachlorane, methoxychlor, chlorotene, etc.) and phosphororganic (metaphos, thiophos, parathion, phosamide).

Course of the disease. Depending on the nature of the action of the poison, its concentration and the type of food collected by the bee (nectar or pollen), the disease proceeds in different ways. When collecting bee nectar, containing high-speed insecticides, its death occurs quickly. Poisoned bees usually do not have time to return to the hive and die in the field or on the way to the apiary. In such cases, the disease lasts for a short time and does not cause significant harm to the bees.

When collecting nectar containing a slowly acting insecticide, or when collecting polluted pollen, bees manage to bring them to the beehive and signal to other bees about the place of their collection. Bees make a massive flight into the poisoned zone and bring in a beehive abundant amount of poisoned food. In such cases the poisoned food of the bee-collector is transferred to the beehives, and the mass extinction of adult bees of different

ages occurs. This phenomenon is most pronounced in strong families, who took an active part in the collection of poisoned food. With the mass death of bees, a discrepancy is soon found between the small number of remaining adult bees and a large number of broods. The brood also undergoes extinction due to inadequate maintenance (cooling and starvation) and the feeding of adult larvae with poisoned pollen or nectar.

With a small transfer of poisoned pollen, the death of bees can be observed for a long time, sometimes almost all summer.

Symptoms of the disease. Chemical toxicosis manifests itself shortly after chemical control of harmful insects in the flight zone of bees. The destroying bees are in the territory of the apiary, near the tapes, and also inside the hives on their donja. Sick bees fall from the combs, crawl on the bottom and outside the hive, on the ground. They are initially in an excited state, and then in an oppressed state. When poisoning with arsenic preparations, as well as some organic synthetic poisons, the death of bees occurs quickly after the appearance of their first signs.

When poisoning with arsenical poisons, some bees develop diarrhea, discharge from the mouth. Therefore, when examining the intestines of bees poisoned with arsenic, honey goiter and intestines are often empty.

Bees, poisoned by organic poisons, are initially in a highly excited state: they soar and fall, rapidly produce circular motions, their abdomen produces frequent respiratory movements. In the future, oppression begins. They lose mobility for a long time, and then perish.

Diagnosis. For the investigation of chemical toxicosis, 500 bees, 100 g of honey, a piece of honeycomb 15 X 15 cm with a pug or affected brood are sent to the laboratory from each affected family. Bee and honey are packed in glassware or parchment paper. Together with the material, a letter or act is sent indicating the factory name of the chemical used to treat the plants before the bees died on the apiary, the date and method of using the chemical. The material should be delivered immediately, otherwise it will be decomposed. The laboratory is diagnosed with the help of biological and chemical studies.

Prevention. Close contact of beekeeping organizations is necessary with plant protection specialists and veterinary organizations. Spraying of gardens and other agricultural plants with microbiological preparations – entobacterin, dendrobacillin, boverite – is harmless for bees. When plants are treated with chemical poisons, plants are sprayed before flowering. It is necessary to notify the beekeepers in advance about the time of carrying out measures to combat harmful insects. Before the beginning of these works apiaries are taken out for 5 km from the place of processing of plants.

If it is impossible to take out bee colonies, then the hives are removed to dark cool rooms or kept in an apiary in closed hives. In this case, the hives are filled with empty honeycombs additional enclosures or magazine extensions, the nail is cut from above with a metal mesh, covered with a roof, the flaps tightly covered with a wooden liner. Daily these families are given water. When treating plants with arsenic and fluoride preparations, bees can not be allowed to leave for four days; hexachlorane, thiophos and vofatoksom – for three days; metaphos – two days; DDT – one day; anabasine, nicotine and feverfew – for five hours.

Control measures. Sick families feed 3-4 days with liquid sugar syrup. If the disease is delayed, remove honeycombs from the nests with pergolas and re-heat them to wax.




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Chemical toxicosis of bees