Chapter 8 Adverse natural factors and pests
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Natural enemies and posts
In this chapter, environmental problems which the bee industry is likely to face will be discussed in some detail, and, where possible, suggestions will be made on ways and means of counteracting them. These problems are grouped into three categories: natural climatic conditions, man and his activities, and natural pests.
The amount of annual rainfall and the temperature of an area exert a great influence on the life and work output of the honeybee. The insect has been called a "summer bird", for it performs most energetically at relatively high temperatures, up to 35°C. Its activity slows when the temperature drops below 20°C, and bees will not move at all below 8°C. Fortunately, such low temperatures are rare in Africa.
At low temperatures, comb building ceases. Bees remain indoors and cluster to generate heat to keep themselves warm. To fan themselves or to cluster, they need fuel to burn; honey fuel allows them to perform these functions. Therefore, if one of these two activities is allowed to continue for long, field bees will not fetch food and other necessities of life, and the colony will have to depend on honey stored in the comb cells. The same phenomenon occurs during rainfall or the rainy season. Indeed, honey stored is for consumption during bad weather such as the chilly rainy season. If bees are confined because of unfavourable weather, an average colony may consume as much as 1.4 kg of honey in a day. Should this continue, whole stores of honey may be completely depleted and the colony will face famine.
On the other hand, temperatures above 37°C are equally unfavourable for the honeybee. At very high temperatures, combs begin to melt and most of the bees in the hive will move out and fan themselves and the brood nest frantically. At such temperatures, bees will spend all their time fetching water to cool the hive, and nectar collection will cease completely.
It was previously mentioned that the equatorial evergreen rain-forest area does not support any reasonable beekeeping activity. In the dense forest regions of Africa, the annual rainfall may range from 1 500 to as much as 10 000 mm, and the peak rainy season occurs from mid-June through July. It is at this period that most bee colonies swarm, and they therefore have to solve their accommodation problems promptly: if suitable hollows are not available, the swarm will hang in the open and drown. The problem of the swarm does not end there. A young virgin queen leading a secondary swarm must make her mating flight. A temperature of about 21°C is required for the drone to leave the hive, while the queen bee flies out at about 24°C. If the rain continues for a long time and low temperatures persist, the queen's nuptial flight will be delayed. After a week, the workers will become angry and may kill her or, if she is allowed to live, she will begin to lay unfertilized eggs. Once she starts egg-laying, the nuptial flight cannot take place and that will spell the doom of the entire colony.
Other problems are also encountered by the honeybee in the dense equatorial forest:
- Some trees are so tall that worker bees will not visit them for any reason.
- Tall trees in the equatorial forest have few or no flowers, so that nectar and pollen are scarce.
- The sun's rays cannot reach the forest floor, the thick undergrowth prevents the free flow of air, and the temperatures are too low to induce worker bees to fly out to procure the commodities essential for the colony.
- High humidity levels promote serious fungal diseases in the insect.
- High moisture content in the nectar prevents honey from curing well.
- Ants, reptiles, birds and other hive predators are present in the forest in large numbers.
It should be noted that the absence of honeybee, from the forest in adequate numbers hampers adequate pollination, and this affects crop yields. This explains why some fruit crops (e.g. mango and orange) cannot perform well in dense forests; even though the plants grow taller and larger, they always bear less fruit than might otherwise be expected.
The savannah and semi-arid regions occupy over 50% of Africa's total area. These regions ideally could support large-scale commercial beekeeping, because their climatic conditions favour the honeybee. Almost every shrub and tree found in the region produces flowers. Grasses are wind-pollinated, but it is common to find bees visiting some of them, including guinea corn, millet and maize. These regions have few beekeeping problems, the most important being inadequate surface water and the dry harmattan wind.
The density of human population suggests the degree to which an area is geographically favourable for man and animals, and also for bees. In general, most arid and desert areas of Africa are fertile lands which only require water in the form of either rainfall or irrigation. In Egypt, for example, thanks to the presence of the Nile River for irrigation, parts of the land support high-density human settlement. The irrigated areas have several tree crops and enough water to support abundant bee life. The days are bright and warm. There is little or no rainfall to disturb flight activities. There are abundant drought-resistant plants which when in bloom provide nectar and pollen to support strong bee colonies.
Sparsely-populated areas, on the other hand, are like the dense forest regions in that they do not support beekeeping. They have the same wild plants and warmth as the densely populated savannah to support the honeybee, but they lack year-round surface water. In several uninhabited savannah woodland areas of West Africa, for example, the annual rainfall may exceed 1 000 mm, but the torrential rains come within two months and leave a long period of the year with barely a shower. The porous soil cannot retain the rain water for long, and the harmattan winds aggravate the situation: the dry, thirsty wind drains all moisture from both the soil and the plants. The trees shed their leaves quickly, and there are no flowers to support the honeybee. Colonies which began life during the rainy season quickly migrate to other regions where they can survive.
The worst of all the enemies of the honeybee is man. In his attempt to improve his living conditions, man has caused, and is still causing, great damage to nature. Trees that support bee life are hacked down, and houses are built on fertile soils which would support crops. Forage trees and forests which took millions of years to develop are destroyed in decades. The bee population is falling off, as their places for food and shelter are being destroyed through the work of lumbermen, road builders, building constructors and farmers. The farmer is the most guilty, and he is also the most severely punished for destroying his own environment. He has cleared all the bush covering the soil along the banks of the rivers which provide him with water, thus exposing the water to direct sunlight and increasing the rate of evaporation and soil erosion. The catchment areas that our grandfathers used have been cleared, and the water-tables have therefore dropped seriously. Drought and famine, which are causing a mass exodus from the land and untold human suffering in wide areas, are thus to a great extent the result of man's careless utilization of the land.
A well-implemented reafforestation programme is the best -indeed, it is probably the only -- means of halting the desertification that is threatening ever-larger zones of Africa. If every able-bodied person in a country of 10 million people planted only one tree a year, the country would have 100 million new trees in only 10 years. Beekeepers, however, should set their own, much higher, targets, planting quick-maturing bee-forage trees (eucalyptus is perhaps the best) to cover once again the banks of streams and rivers and all other areas known to have water-tables. They should also plant fruit crops that, with the help of the honeybee, could yield fruit, honey and beeswax for man. Many apiaries could be sited in such man-made forests. The bees would find their food and water naturally, while man would gain several immediate advantages and lay a sound foundation for future generations.
As mentioned very early in Chapter 1, honey-hunters using outdated, barbaric methods are a terrible danger to the bees. Not only do they deliberately kill many of them, but as they cut down trees to take the colonies' combs, they destroy the tree hollows that are the bees' natural home. The colonies are thus forced to hang outdoors, exposed to all their natural enemies. And if the bees are destroyed, they cannot fertilize flowering crops, and this again contributes to famine conditions.
For all these reasons, the activities of the traditional honey-tapper, the main present supplier of honey in most African countries, should be very strictly controlled. Governments should not only regulate honey-hunting and enforce the regulations once made, but should also make serious efforts to instruct honey-tappers in the newer, more efficient ways of honey-hunting, as well as to encourage them to keep bees themselves.
One of the greatest problems in the savannah and the transitional forest zones is bush-burning. This practice is rampant during the dry season (generally from November to Hay). Some obvious reasons for bush-burning are (i) to clear the land for farming (ii) and to clear the bush and make hunting easy. The honeybee population suffers greatly from such fires' in a wild fire that consumes an area of 250 square kilometres, with only one colony for every 10 hectares, about 125 million bees could be destroyed.
The beekeeper must guard his hives against bush fires. Before the dry season, he should make a fire belt around the apiary and visit it as frequently as possible, removing any fallen wood or leaves which could spread a fire on the site.
Where water is scarce during the dry season, the honeybee makes life difficult for man. The streams disappear, and it becomes necessary to travel several miles to fetch a head-load of water for domestic purposes. At the same time, the temperature is high, and the harmattan wind drains all moisture from the honeycomb. There are larvae to feed, and this requires water, but the honeybee can only travel three kilometres. If she cannot find water in the streams, then that bucketful of water which the villager has collected must be snatched away. The bees will lay claim to-it in large numbers. Returning from the farm late in the evening, the exhausted, thirsty farmer finds that his only bucket of water has been drained by the bees. What is more, the bees harass the women pounding grain. In extreme cases, they try to suck human sweat, and this results in a scuffle.
In some places, therefore, the villagers hunt the bees and burn them. In one village in Ghana, a government officer said,
"We deliberately burn them in order that we can live peacefully in this area."
Bees must be watered in the same manner as birds are watered on a poultry farm. The surest way to prevent bee-burning is to provide a regular water supply for bees as well as for human consumption in the dry season. In planning a beekeeping project in the savannah area, it is essential to provide adequate water for bees as well as for humans, in order to prevent bee attacks from causing loss of life or other serious inconvenience.
The palm-vine tapper
The palm tree produces a sweet, refreshing liquid which is drunk by man in many tropical countries. The honeybee also refreshes herself with this type of wine from the pot of the wine-tapper. The honeybee begins to leave the hive as early as 5 a.m. The wine-tapper usually makes sure he reaches his wine very early, but by the time he removes his first pot of wine from the tree, many bees have already been there. They fill themselves with wine and become tipsy. In extreme cases, the whole pot of wine is consumed, and many bees drown. The wine-tapper, furious at the sight of the countless bees lying in the wine pot, sometimes collects all the bees and throws them away or kills them. If he assumes that the motionless, tipsy bees are dead, he does them no further harm. However, most of the bees left unmolested will eventually recover and return to the hive.
In general, drunken bees are like human drunkards. They work less and produce little honey. Apiaries should therefore not be set up near places where vine-tapping is in progress. Colonies may dwindle in size and may perish completely as the insects are burned, crushed or drowned.
As the honeybee visits plants during her search for nectar or pollen, she flies from one plant and flower to another. Sometimes the insect unknowingly lands on a poisonous plant or contacts a poisonous pesticide which the farmer has sprayed to protect his crops. (According to a report published in 1973, out of 399 pesticides, 20% were highly toxic to bees, 15% were moderately toxic and 65% were relatively non-toxic.) Pollen collectors may carry this poisoned pollen into the hive and store it for future use by the bee brood. As long as the poisonous pollen remains in the cells, it poses a dangerous threat. It may kill both adults and brood, either by contact or by ingestion. This intensive hazard of pesticide poisoning sometimes overshadows all other problems, for example when an entire orchard is sprayed by aircraft. Beekeepers are strongly advised to keep their hives away from sprayed fields.
Natural enemies and posts
The greatest natural enemies of the honeybee are all types of ants: driver, tailor, black, red, brown, large or small, all are dangerous to the hive. They eat sweets such as nectar, honey, sugar and the bee's body. They like to live in hollows like the bee, and the same empty beehive produced by man for bees can also be a good home for them. The hive must therefore be protected from ants.
All four wires or the legs of the hive should be protected by insect repellents. The part of the suspension wire nearest to the branch on which the wire hangs should be coated with thick grease. The legs of the hive stands can also be protected with grease, but the best insect repellent to use with hive stands is dirty engine oil, each leg of the stand being placed in a shallow container full of the oil. Spreading wood ash or charcoal ash around the stand will also keep ants away.
A newly installed beehive should be visited frequently to check whether it has been colonized by bees or ants. Destroy every ant found in the hive.
Wax moths (Galleria mellonella and Achroia grisella)
The wax moth is the bee's second worst enemy. There are two types: greater and lesser wax moths. They attack colonies during the warm periods of the year. Strong colonies are able to repel them, but weak ones are susceptible to attack. The moth itself does no harm to adult bees but does harm the larvae. The female, which is slightly smaller than the honeybee, enters the hive freely and lays her eggs in the combs. The eggs hatch in three days, and the emerged larvae begin to eat the wax, tunnelling through and destroying the comb cells, and spinning web-like cocoons about themselves for protection against the bees. They are capable of destroying all the combs in a hive. The bees may leave the hive and cluster on a support near the apiary. If the beekeeper's attention is drawn to this, he can sometimes prevent the colony from absconding by cleaning all the destroyed combs and removing all the larvae of the wax moth. The bees may return to the hive and start all over again.
When the wax-moth reaches its pupal stage, it digs hollows in wood for its cocoon and by doing so damages or destroys the inner surface of the hive and the top-bars. (See Fig. 15.)
Weak colonies can be protected against wax moth by making them strong, for example by uniting two or three colonies. The moth usually enters a hive to lay her eggs when a colony swarms.
When strong colonies swarm, most of the bees leave the hive, and the few which remain may not be able to cover all the combs. Unguarded combs should be removed, stored and replaced later as the colony increases in size.
The entrance of a weak colony should be reduced to enable the few "security officers" to guard it effectively. Other holes which can serve as entrances to the hive will surely be used not only by the moth but by other hive predators as well. Such entrances should be sealed off as soon as they are discovered.
Lizards, reptiles measuring about 25 cm from head to tail, are mostly found in backyard gardens, in villages and the outskirts of the city. The activity of the "home lizard" may cause great concern to the beekeeper. It sometimes stays very close to the hive or accommodates itself comfortably between the lid and the hive body, if it can find an entrance. From that convenient spot, it may feed indefinitely on the bees.
Even lizards not living near the hive will feed on the bees once they can locate the apiary. Although they prefer dead bees, they will eat live ones as well. A worker bee, acting as a scavenger, will pounce on an old, lazy or sick bee and try to tear the victim's wings, breaking them into pieces. While this action is in progress, the lizard will rush in and lick both of them up with its sticky tongue.
A serious lizard problem may lead to absconding. The simplest and most practical protective measure is illustrated in Fig. 8 on page 52. Beehives are installed on a platform, with metal cones nailed on the legs about 70 cm above the ground, to prevent lizards from reaching the hives.
Toads use the same methods as lizards, and will remain in the apiary if they can get bees to eat. The toad generally consumes only weak and dead bees, but if it can reach the hive, it will eat live bees as well. The toad does not pose as many problems as the lizard because it cannot climb. The best means of protecting hives against toads is therefore to install them at least 60 cm above the ground.
Some snakes are known to eat bees. They do not cause much damage to the colony, but the beekeeper should always be careful to avoid being bitten by a poisonous snake near the hive.
This large moth is well known in the forest for entering hives between June and November. It makes a special sound which paralyzes the bees, and they may refrain from attacking it. The moth may then be able to load its stomach with honey. Sometimes the bees are able to catch the moth and break it into pieces. The dead Atropos may be found disposed of near the entrance of the hive.
Since the wing-span of the moth is as wide as 12 cm, Atropos cannot enter any hole which is only 8 mm in diameter. The use of hives with slot-like entrances should be avoided if the area is infested with this insect.
The bee pirate
A wasp-like insect with orange and black skin is sometimes found molesting the field bees entering and leaving the hive. This insect is usually active between October and May. There is nothing the beekeeper can do to stop it, but it cannot cause any great harm to a colony of bees.
The praying mantis
The praying mantis also eats bees, but this insect cannot cause any great damage to a colony.
The spider constructs webs around in the apiary or in an empty hive. Once the web catches bees, the spider will eat them.
All webs found in or near the apiary should be destroyed. The hive should be cleaned and all webs found within it removed. Otherwise, the scout bees will be caught and eaten, and no swarm will ever take possession of the empty hive.
The Alpine swift
This bird is well known for eating bees. The birds arrive in December and stay on for several weeks, usually causing considerable losses.
There are other organisms which follow a swarm and settle with them in the hive. Some harass the bees, and the Workers are often found trying to drive them away.
The hive beetle (Aethina tumida): This is a small black or brown insect with an armour-plated shell which the honeybee is unable to crack with her mandibles or sting to death. The beetles are found in the hive every day, and their number increases during the honey-flow season. A colony of bees containing large numbers of this insect produces less honey than one of the same size without the insects. The bees try to keep them away, but as the bees chase them out, the beetles resist and waste the honeybees' time. There is no known way to eliminate them.
The bee scorpion (Pseudoscorpion): This insect, as the name implies, looks like a scorpion. It usually clings to the legs of the bees and accompanies them to the nest. The worker bees try to drive them away, but like the Aethina tumida, the pseudo-scorpion will never go away.
The bee louse (Braula): One or two may be found on a worker or drone, but more are usually found on the queen bee, probably because the braula enjoys taking royal jelly; hence, it would be the first to partake of the food whenever the queen is served. The worker bees never attack them, but the queen can be deloused by catching her and holding her between the thumb and the middle finger, placing a live cigarette ash on the louse. It will quickly fall off. It can also be smoked out with the smoke of a cigarette.
Creatures found in or near the hive which constitute no danger to honeybees are the little green lizard, wall gecko, some small frogs and the cockroach. They are usually called the bee friends. They eat some insects which encroach upon the hive such as the wax moth, the house fly, the blue-bottle fly and the mosquito. However, there is some doubt whether the cockroach is really a good friend to the honeybee.
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