Bee acariasis
At present, more than 30 species of mites have been found in the body and hive of bees. Among them, the big wasp mite and the small wasp mite belonging to the family Lepidoptera are seriously harmful to the beekeeping industry in China.
(1) The male of varroa mite is oval, the size is 0.88× 0.72 mm, and the female is transverse oval, dark reddish brown; The back is covered with a backboard, and the ventral surface is covered with reticular patterns and dense bristles. There are chest plate, reproductive plate, anal plate, abdominal thigh plate, abdominal lateral plate and other structures. The mouthparts are piercing and sucking, with keratinized claws, long moving fingers and short degeneration of fixed fingers; Four pairs of feet, short and thick, with bell-shaped claw pads at the ends. Eggs are oval and milky white. The size is 0.6×0.43mm, the egg membrane is thin and transparent, and 4 pairs of limb buds can be seen in the egg when laying eggs. The early nymph is milky white, with sparse bristles on the body surface and four pairs of stout feet. Its shape gradually changed from oval to nearly round, and its size increased from 0.63×0.49mm to 0.74× 0.69 mm. In the early stage, it was a late nymph, and its shape changed from heart-shaped to transverse oval, and its size increased from 0.80× 1.09.
(2) Male red mite is ovoid, light yellow, 0.95×0.56mm in size, with dense bristles on the back plate. The ventral chest plate is combined with the reproductive plate to form a tongue shape, but separated from the anal plate, and the anal plate is oval. Female mites are ovoid, light brown, slightly larger at the front end and blunt at the back end, with the size of 1 .03× 0.56 mm. The back plate is densely bristly, the front edge of the ventral chest plate is straight, the rear edge is extremely concave, the front angle is long, reaching1,and the reproductive plate is narrow and long, almost reaching the front edge of the anal plate, which is bell-shaped. The egg is nearly round, with transparent membrane, and the size is 0.66× 0.54 mm In the early stage, the young mite is milky white, oval, with fine bristles on the back, and the size is 0.54× 0.38 mm. After molting in the early stage, it is oval, and the size is 0.9× 0.61mm.
Life history and habits: Female bee mites sneak into the hive before bee larvae are covered. When bee larvae are covered, female bee mites lay eggs and reproduce by absorbing the body fluids of bee larvae. The eggs first hatch into nymphs, and the egg period of wasp mites is 1 day, and the nymph period is 7 days, and then they further develop into mites (a female mite can lay 1 ~ 3 eggs at a time, and the oviposition can last 1 ~ 2 days), and the adult mites climb out of the nest with the young bees when they leave the nest; The newly-born female mites parasitize the chest and abdomen of bees and suck the body fluids of bees, while the male mites do not feed on bees and die immediately after mating with the female mites in the covered larval room. The average life span of adult mites in the breeding period is 43.5 days, the longest is 53 days, and the wintering period can be more than 3 months.
, U 1M"L5`3A Veterinary teaching reference, veterinary clinical communication, auxiliary diagnosis system of canine diseases. The whole life process of bee mites is partially parasitic on the spleen of the hive and feeds on the body fluids of bee larvae. Female mites sneak into the larval chamber and are covered to lay eggs and reproduce. After a larva is killed by parasitism, the bee mite can crawl out of the hole in the closed room and sneak into other larva rooms to lay eggs and reproduce. When the new bees leave the room, the newly grown bee mites crawl out together with the new bees, and then sneak into other larval rooms for parasitic reproduction. The whole development process of bee mites only takes 4 ~ 4.5 days.
Stealing bees and bees among bees are the main vectors for the spread of bee mites. In addition, when beekeepers change their spleen or adjust their bees at will, it will also cause the spread of bee mites.
Symptoms When bees are killed, one of the most obvious features is that deformed bees with weak wings can be seen near the hive door and on the spleen. After bee larvae are killed by bee mites, they stink. Pick them, don't pull them. Easy to eliminate. Bee pupae remain intact and have no special smell, but the head and chest are darker, the abdomen is lighter, sometimes slightly green, and the mouth and feet turn yellow. Pick out the dead pupae, and you can also observe the bee mites at different development stages in the nest room. After being parasitized by bee mites, adult bees often twist their bodies in an attempt to get rid of bee mites, which makes bees exhausted and accelerates aging. In many cases, worker bees, drones and queen bees come out of the nest room, which is normal on the surface, but it has been damaged due to the parasitism of bee mites. The life span of bees is shortened, drones can't mate, queen bees can't fertilize, and they can only lay drone eggs.
Diagnostic test method: (1) direct test: the spleen with bee larvae was taken from the bee colony, randomly sampled, 50 ~ 100 worker bees were caught, and their abdomen and chest were carefully examined for bee mites. At the same time, 30 ~ 50 bee-covered nests were uncovered with ophthalmic tweezers, and whether there were bee mites parasitized on the pupa and in the nests was observed with a magnifying microscope. Then calculate the parasitic rate according to the inspection results. The inspection method of wasp mite is roughly the same as that of wasp mite. It is important to check the spleen of the lid because the wasp mite is parasitic in the larval chamber of the bee.
(2) Drug fumigation inspection: Take a wire bee cage (10cm×10cm×10cm), take out the spleen of a bee larva from the bee colony, grab 50 ~ 100 worker bees at will, put them in the bee cage, and bring them back indoors to be buckled in a big beaker. At the same time, cotton balls soaked in 0.5 ~ 1 ml ether were put in and fumigated for 5 ~ 10 min. After all the bees were in a coma, the bee mites were also shot down. Then put the bees back to the nest door of the original group, and the bees will return to the nest after waking up. The parasitism rate of bee mites can also be obtained by treating bees with carbon dioxide gas as described above.
Prevention and treatment
(1) Integrated control method: According to the biological characteristics of bee mites sneaking into the sealed larval chamber of bees, artificial seed breaking method is adopted to stop the queen bee from laying eggs for a period of time. There is no sealed spleen in the bee colony, and all the bee mites parasitize the bees, and then drugs are used to drive them away. There are many kinds of drugs used, among which acaricide (20%) has the best effect and is safe for bees. When in use, avoid the honey picking period and spray 0.025% ~ 0.05% water on the peak to kill mites. Alternatively, two mites are selected from each flat box and hung on the bee path between 1 and the second nest spleen and the seventh and eighth nest spleen in the bee colony for 3-4 weeks, so that the acaricidal effect is transmitted due to the activities of bees.
(2) Put forward the method of blocking sub-cards and grouping prevention and control: According to the biological characteristics of giant bee mites parasitic on bees and breeding in the blocked nests of bees, this method is adopted. In autumn, when the honey flow period is over, adjust the bee colony, merge the weak colony or form the double king colony, and add the relay box at the same time. Then, all the covered spleens in the bee colony are taken to the trunk, and the oomph spleen, pink honey spleen, appropriate empty nest spleen and queen bee are left in the hive. The nest box and relay box are separated by gauze cover and divided into treatment group (relay box group) and eclosion group. Immediately after treatment, the treatment group and the emergence group were treated with acaricides (quick acaricide and acaricide I) for 2-3 times, every 3-4 days 1 time. After the young bees covering the spleen in the eclosion group leave the house, treat the mites for 2 ~ 3 times according to the above method until there are no bee mites, and then merge the upper and lower groups for reproduction. This kind of mite control effect is quite thorough, and it is suitable for keeping bees in open space. Because of the complicated operation, at present, it is often used to hang "mites" directly in the bee colony to kill mites, which is much simpler to operate.
(3) "One-time" method of killing mites: This is the research achievement of China in the 1980s. Before prevention and control, all the spleen seals in the bee colony should be hoisted out and put into the empty trunk. Put 7 ~ 8 pieces of spleen on each trunk, no bees. Then spread a layer of plastic cloth on the bottom of the relay box, then spread two layers of absorbent paper on the plastic cloth, and dissolve 10 ml "powerful" nest acaricide (with formic acid as the effective component) in the absorbent paper, and the other two or three boxes can be stacked in turn. Under the condition of temperature above 22℃ and closed fumigation for 5 hours, the acaricidal effect reached over 98%. After mites are controlled, the spleen will return to its original state. At the same time of killing mites, the "quick killing mite" spray is used to drive away mites on bees, and the control effect is more thorough. Bromopropyl ester is a new type of low toxicity and non-toxic (carcinogenic, teratogenic and mutagenic) acaricide, which is used to make cigarette paper. After bees return to their nests in the evening, they hang cigarette paper on the empty nest frame in the hive and seal the door 15min. The acaricidal effect is over 90%, which is relatively safe for bees. There are similar products in China, such as acaricide No.3, which is a kind of acaricide for domestic animals and also has special effects on killing bee mites. Only 0.0025% bee spray can 100% kill the giant bee mite on bees. The usage, dosage and acaricidal effect of Diptera 1 are the same as those of Sulklin. The latter is used once a week, and after two consecutive uses, it can not only kill mites on bees, but also kill bees in the nest (internal inhalation acaricidal effect). Maplik is a pyrethroid acaricide. Put two bees in each colony, and put them on the bee path between 1 and nests 2, 7 and 8 respectively (hanging and fixing), which can be kept for 5 ~ 6 weeks continuously, and the acaricidal effect can reach over 98%. No matter what kind of acaricide is used, especially water agent or emulsifier, the honey harvesting period should be avoided. In early spring and late autumn, it is effective to control mites during the period of group breakage or after long-distance transportation. Use different drugs according to different conditions such as external temperature and colony potential. If the temperature is low in early spring and late autumn, fumigant should be used, while in summer, fumigant should be used. Anti-mite fumigant: it is a patent medicine for treating large and small bee mites. The dosage should be accurate to prevent damage to young bees (please follow the instructions for details). Mifenling synthetic fumigant: a new type of acaricidal drug, which is particularly effective in controlling large and small mites and does not harm young bees. Nicotine (nicotine): 0.5 ~ 0.6 ml for each group, dripped on the filter paper, fumigated at the bottom of the box at night, with good effect and safety. Dermatine: use the commercially available emulsion containing 2.5% or 7.5% rotenone, dilute it with water to 1500 ~ 2000 times, and then spray it on the spleen. Spray each spleen 3 ~ 4 times until the bee wings are slightly foggy. It is beneficial to the mite, spraying 1 time every two days or so, and continuous treatment for about 4 times. Bayvaro 1 strip is the latest acaricide synthesized by Bayer Pharmaceutical Factory in Germany. It is convenient to use, and the harm of bee mites can be effectively controlled by hanging two pieces of bee mites in each box. It is effective for both big and small bee mites, and can quickly kill big bee mites within 24 hours. The drug effect lasts for 6 weeks, which is safe and harmless to people and animals.