=The Blind Louse.=--This is a parasite fairly common in this country, and the bees, both hive and wild varieties, are favoured by it as hosts. Although it is said to be harmless, it must be treated with suspicion, and if its presence in a hive be detected steps should be taken to get rid of it. If tobacco smoke be blown into the hive, the parasite will loosen its tenacious grip and fall to the floorboard of the hive. Its destruction is then easy. Before the floor-board is replaced it should be washed with hot water into which a few drops of carbolic acid have been dropped. =Pollen Mites.=--Amongst the smallest of the insects visible to the naked eye these little creatures work--as their name suggests--among the pollen stored by the bees. They are about the size of a grain of pollen and prefer the pollen when it is damp either with honey or water. It is a commendable practice to keep combs that contain pollen by themselves when they are not in use. =Spiders.=--In this country the spider is not to be so dreaded by the bee-keeper as it is in hotter climates. For cleanliness' sake, however, it is well to keep the hive clear of its webs. =Green Fly.=--It is the bee-keeper rather than the bee that has cause to dislike the green fly. To the bee, indeed, the aphis ranks as great a friend as it does to the ant. To both it is the excretion with which the aphis surrounds itself that is the attraction. To the gardener and the bee-keeper, however, it is an abomination to be warred against by all means at command. The excretion of the aphis, popularly known as "honeydew," is white when at first sprayed out by the little creature, but after it is stored by the bee in the comb its presence is marked by a dark patch in the honey, and the bee-keeper knows that the latter is spoiled. This dark colour is attributed to a fungus generated by the honeydew. Where large quantities of honeydew are contained in combs the most economical method of dealing with the latter is to give them to the bees for drawing-out combs, for it is practically impossible to separate the honey, and for commercial purposes the presence of honeydew is prejudicial. Occasionally honey that contains honeydew will crystallise, sometimes to look like a sponge, and in such cases the honeydew can be run off. If not so treated it will ferment and permeate the candied honey. =Wasps.=--When particularly numerous, wasps become a source of anxiety to the bee-keeper, and it is therefore to his interest to aid in keeping their numbers down as much as possible. The usual method is to destroy the nests before the queens are hatched out--which generally occurs about the middle of September. =Snails and Slugs.=--Here again the bee-keeper and the gardener are at one in their efforts against common enemies. It is probably due to the trail of slime left by both slug and snail that the bees do not care to interfere with these intruders to the hive and leave them to roam about at their leisure.