INSECTA, in Natural History, a smaller fort of animals, commonly supposed to be exsanguious; and distinguished by certain incisions, cuttings, or indentings in their bodies. The word is originally Latin, formed of in, and seco, "I cut;" the reason of which is, that in some of this tribe, as ants, the body seems to be cut or divided into two; or because the bodies of many, as worms, caterpillars, &c. are composed of different circles, or rings, which are a fort of incision. See ENTOMOLOGY.

Noxious INSECTS; Means of destroying them, or preventing their Increase. The following remedies we find collected in the Gentleman's Magazine for October 1795.—Of those substances which have been generally observed to be efficacious in driving away or in destroying insects, mercury, and its various preparations, may be reckoned one of the most generally useful. Sulphur is also useful. Oils of all kinds have been often and deservedly recommended. Tobacco is not less remarkable for its utility. Of the application of these in order,

1. Mercury is known to kill or drive away lice from the human body; and it may probably be of equal efficacy in ridding other animals of their insects. For instance, sheep having a small quantity of mercurial ointment rubbed on their skins, on the sides, between the fore-legs and the body, it may kill or drive away the insect peculiar to them. Sulphur is recommended to be added to the mercurial ointment. Thus not only the insect peculiar to them, but also the scab, may be cured: See the Transactions of the Society for the Encouragement of Arts, London, vol. vii. viii. p. 90. In the Transactions of the same society, vol. v. vi. p. 59. Mr Allway directed that, in the winter, the walls, frames, &c. of his green and hot-houses should be well washed with the following mixture: Take of corrosive sublimate mercury four ounces, and dissolve it in two gallons of water. These houses had been greatly infested with red spiders and ants. After having been washed with the above mixture, neither were to be seen next summer. This wash may be used on old garden-walls, and to the roots of fruit-trees infested with insects, if made weaker. It may destroy the tender leaves of plants, though not the roots. This wash will effectually destroy that disagreeable insect the bug, and all other insects of a tender cuticle; and it will not in the least hurt the colour of bed-furniture or hangings. Care must be taken that the wash be applied into every crevice or folding of the furniture with a painter's brush. It will sometimes be necessary to repeat the wash, as some of the ova of bugs may remain concealed, notwithstanding the utmost care.

Some of the West India islands were much infested with large ants, which greatly hurt the sugar-canes. The remedy was, to dissolve corrosive sublimate mercury in rum, in the proportion of two drams to a pint of spirits. This solution was poured on dry powdered sugar; and when the sugar was dried, it was laid in the paths of the ants. They ate it, and were destroyed. Might not this practice be imitated, by laying sugar thus prepared on paper or pieces of thin boards near the roots of fruit-trees infested by insects, especially when the fruit is ripening? The papers or boards might be taken in during the night, or when it rained. The sugar should be coloured with indigo, or other substance, thereby to mark it as a substance to be avoided by curious idlers.

2. We are informed that a person in Philadelphia employed brimstone in the following manner. Having cleared all round the roots of trees infested with caterpillars or other insects, he strewed some flour of brimstone round the roots, and covered it with a thin sprinkling of fine mould, that it might not be blown away by the wind, yet so that the sun might operate through, and cause the brimstone to fumigate. Thus he destroyed the caterpillars. One pound he found sufficient for 200 trees. In that hot climate the sun may may perhaps have that effect; but it scarcely will in this. He also employed sulphur in the following manner to drive insects from small trees. He split the end of a pole, and put in the slit some matches, set them on fire, and held them under the parts of the trees chiefly affected. A pole thus armed, he found, would answer for three or four trees. Brimstone thus mixed with damp straw, and set on fire, for instance, in hop-ground infested with the fly, might be of use to drive away the fly.

The itch is supposed to proceed from a very small insect which resides under the skin, and proceeds no farther into the habit; and is therefore attended with no dangerous consequences. Brimstone made into an ointment with hog's-lard is a sure remedy.

Sheep are liable to an eruption on the skin, known by the name of the scab. The brimstone, when added to the mercurial ointment recommended for that disorder in the Transactions of the Society for the Encouragement of Arts, vol. vii. p. 90, might perhaps render the application more efficacious and less dangerous.

3. The natives of hot countries are taught by experience, that an unctuous covering on their bodies prevents the bites of mosquitoes and all gnats. The white inhabitants in such countries are not sufficiently careful in preventing the least stagnant water near their dwellings, in which the mosquitoes are bred; even in the waste water thrown out they are produced. Dr Franklin, by a careful attention to this circumstance, guarded his family in Philadelphia from such insects: one day seeing a number of mosquitoes in his library, he found on inquiry, that one of his servants had taken the cover off a tub placed near his window for receiving rain-water. On such an occasion the remedy is easy, viz. shutting the room up for the day, so that the mosquitoes cannot come at any water, in which time they die. Though this caution may seem trifling to us who live in a mild climate, it is far otherwise in hot countries.

Oil being known to be most efficacious in destroying insects, may not the use of it be extended to the destruction of worms in the bowels of horses, where they may occasion the violent pain they seem sometimes to suffer? If the horse was for some time kept fasting, and a large quantity of oil, suppose a pint, was given, if worms are the cause, the oil may in that case kill them.

Flowers, leaves, and fruit, on plants, are known to be devoured by caterpillars. These are destroyed by oils, which close the lateral pores by which they breathe. For this purpose it is advised, that, on the approach of spring, a cloth dipped in train oil be laid on such parts of the tree in which there is the least appearance of them.

We are informed in the Memoirs of the Society of Agriculture at Paris, that oil of turpentine, when applied to animals which were covered with insects, destroyed the insects without hurting the animal. The author tried it on several trees, mixed with fine earth so as to incorporate them well, then adding water, still stirring them carefully till the whole was brought to some degree of fluidity. In this mixture he dipped branches of fruit-trees on which there were insects, and hereby destroyed not only the eggs but also the insects, without hurting the leaves. This composition may be got of by washing, or the first heavy shower. From these experiments the author thinks, that oil of turpentine may with equal efficacy be employed for killing various kinds of lice on domestic animals.

We are informed, in the Transactions of the Society for the Encouragement of Arts, vol. v. p. 45, that Mr Winter, among other experiments on turnip-feed, steeped the feed 24 hours in a sufficient quantity of train oil. He then drained the oil from the feed, which he mixed with a quantity of fine sifted earth, and immediately sowed it in drills. When the plants began to appear on the surface, the ground was sown with foot. He found that feed steeped in linseed oil answered equally well. The turnips the least injured by the fly were those that grew from seed steeped as above, which grew so luxuriantly as to produce rough leaves several days prior to the most flourishing of any of his other experiments, and were the better enabled to withstand the fly's attack. The leaves of these turnips were of a darker green, and appeared twice as thick in bulk and luxuriancy as the other turnips, and were a considerable deal larger. The feed was drilled an inch and a half deep, and at a foot distance in the rows. Train oil is apt to kill the leaves of plants which have been injured by insects, but linseed oil has not that effect, though equally destructive to the insects. The train oil seems to act both as an oil, and by its disagreeable smell it prevents insects approaching it. In this respect it may be successfully used to prevent field mice or other vermin preying on acorns, chestnuts, or other seeds sown in it before they are sown.

When thus giving directions for preventing the fly on turnips, a late experiment should be mentioned, by the disclosing of which a person gained a considerable reward. His secret was, running a roller over the ground early in the morning, while the dew remained on the ground, on the first appearance of the fly. The dew entangled the flies so much, that they could not make their escape, and were therefore crushed to death. As the roller may leave the surface of the earth too hard, some very properly advise to fix some boughs of elder in a gate or hurdle, to be drawn over the field; and if the boughs had been before fumigated with the smoke of tobacco, or tincture of alumetida, the success would be the surer. The most certain method of preventing the hurt done by the fly is to raise the plants in a nursery, and at a proper age to transplant them, being carried to the ground in a wheelbarrow filled with manure softened with water so as to admit the plants. This method will secure their more speedy growth. In the nursery the attack of the fly may be prevented by sprinkling foot or quicklime on the ground. The utility of transplanting turnips is evident by the practice of transplanting the turnip-rooted cabbage. They who are discouraged from this practice by the expense attending it, do not reflect that the hoeing is prevented, and the plants grow the better, being set in fresh earth.

3. Before proceeding to direct the use of the last means mentioned, viz. tobacco, for destroying insects in turnips, it may be proper to mention an experiment made by Mr Green, of her majesty's flower-garden at Kew. He contrived a pair of bellows similar to that employed in recovering people seemingly drowned. It has has a cavity in the nozzle, in which some tobacco is put, with a live coal over it. The bellows being then worked, the tobacco is set on fire, and the smoke is directed to any particular spot. A lady was fond of having the mokrofe in her dressing-room, but was prevented having it on account of the green insects which constantly adhere to that plant. To remedy this inconvenience, Mr Green had a box made large enough to contain a pot in which a plant of the mokrofe grew. In one end of the box was a hole, to admit the nozzle of the bellows; the bellows was worked, and the smoke was received into the box. When the tobacco was consumed, the nozzle was withdrawn, and a cork being put into the hole, the box thus remained till morning, when the insects were all laid dead on the earth. Being swept off, the plant was in a state fit for a dressing-room. Many plants thus infested with insects may be too large, or otherwise so placed as not to be put into a box. In this case it occurred to the writer of these observations, that being sprinkled with an infusion of tobacco in water might in some degree answer the same purpose. On trial he found it answered, and he thus freed other plants of their insects. He also used it on trees of early access with advantage. Train oil is so inimical to tender plants or leaves, that it destroys them if insects have in the least hurt them; whereas the infusion, instead of killing the leaves, promoted a fresh vegetation.

Fruit trees often become the prey of insects. Those against a wall, or in espaliers, being easily come at, much of the mischief may be prevented by cutting off the leaves so soon as they are observed to be curled; for then fresh eggs are laid on them, probably by butterflies. If sprinkled with the infusion of tobacco, it will prevent their coming to life. After the fruit is formed, the infusion must not be used, lest the taste and smell may remain. The sciaras are then the proper remedies, which ladies may employ as amusements, and may thereby present fruit to their friends of their own preserving. A lye of the ash of plants sprinkled on the leaves may have a good effect, as also on other pot-herbs, which are often the prey of caterpillars. As many insects, besides those bred on the leaves or in the walls, may destroy the fruit, the sugar with the corrosive sublimate, as already described, may be laid in the way of other insects, to all which it will prove a speedy death. Diligent inspection into their retreats is the most certain means of preventing the loss sustained by snails. Ants are prevented rising up the trees, by laying round the roots powdered chalk, or any other substance which by entangling their feet prevents their croaking it. Care should be taken to destroy their nests everywhere near the garden.

Hops are now become an article of so great consequence, that it deserves our particular attention. Early in its growth, when the vines begin to ascend the poles, a black fly preys on its leaves, frequently in such numbers as, by destroying the leaves, to interrupt the vegetation, much of the food of plants being absorbed by the leaves. The infusion of tobacco destroys them, or at least drives them away so effectually, that a plant almost totally stripped of its leaves has put out fresh leaves after the use of it. If care be not taken, they will again fall on the fresh leaves. As the flies lodge on the lower side of the leaves, they are protected from storms of rain, and therefore the infusion must be driven upwards by a forcing pump. As it is said that the expense of tobacco is too great, perhaps lime-water, or even water by itself, driven strongly against the leaves, might drive them away. The labour attending such experiments in a large plantation discourages others, without reflecting, that, if such means are used early, the flies may more easily be got rid of.

Free ventilation is undoubtedly beneficial to all plants; and hence perhaps the particular advantages of drilling corn in rows a little distant. If alleys somewhat larger than common were made in the plantations of hops, there might be sufficient spaces left where the alleys cross one another to admit of setting damp straw, or other materials mixed with brimstone, foot, &c., on fire. Smoke itself is said to prevent the fly; and if so, it will still act more powerfully when mixed with such materials. It has been observed in Sweden, that the hops grow naturally among heaps of stones or fragments of rocks. They therefore advise to cover the ground round their roots with stones, which will prevent the insects laying their eggs near the roots in the ground, where they lay them to be protected during the winter. The stones will also preserve moisture at the roots during the summer. A rope cannot be drawn across a plantation of hops, as it can across a field of corn, in case of mildew. Here water to wash off the clammy juice that entices and feeds insects seems to be the only remedy. The plantation being well ventilated, may at least prevent the frequency of it. The forcing pump will most effectually wash off this exudation.

Cruelty to INSECTS. It does not appear upon what principle of reason and justice it is, that mankind have founded their right over the lives of every creature that is placed in a subordinate rank of being to themselves. Whatever claims they may have in right of food and self-defence (to which ought we to add the purposes of the naturalist, explained above?) did they extend their privilege no farther than those articles would reasonably carry them, numberless beings might enjoy their lives in peace, who are now hurried out of them by the most wanton and unnecessary cruelties. It is surely difficult to discover why it should be thought less inhuman to crush to death a harmless insect, whose single offence is that he eats that food which nature has prepared for his sustenance, than it would be were we to kill any bulky creature for the same reason. There are few tempers so hardened to the impositions of humanity, as not to shudder at the thought of the latter; and yet the former is universally practised without the least check of compassion. This seems to arise from the gross error of supposing, that every creature is really in itself contemptible, which happens to be clothed with a body infinitely disproportionate to our own, not considering that great and little are merely relative terms. But the inimitable Shakespeare would teach us, that

—the poor beetle that we tread upon,

In corp'ral suff'rance, feels a pang as great

As when a giant dies—

And indeed there is every reason to believe that the sufferings of many insects are as exquisite as those of creatures of far more enlarged dimensions, perhaps even more so. The milipede, for instance, rolls itself round upon the slightest touch, and the snail draws in its horns upon the least approach of our hand. Are not these the strongest indications of their sensibility? and is it any evidence of ours, that we are not therefore induced to treat them with a more sympathising tenderness?

Montaigne remarks, that there is a certain claim of kindness and benevolence which every species of creatures has a right to from us. It is to be regretted that this general maxim is not more attended to in the affair of education, and pressed home upon tender minds in its full extent and latitude. We are far, indeed, from thinking, that the early delight which children discover in tormenting flies, &c., is a mark of any innate cruelty of temper, because this turn may be accounted for on other principles; and it is entertaining unworthy notions of the Deity, to suppose he forms mankind with a propensity to the most detestable of all dispositions; but most certainly, by being unrestrained in sports of this kind, they may acquire by habit what they never would have learned from nature, and grow up into a confirmed inattention to every kind of suffering but their own. Accordingly the supreme court of judicature at Athens thought an instance of this sort not below its cognizance, and punished a boy for putting out the eyes of a poor bird that had unhappily fallen into his hands.

It might be of service, therefore, it should seem, in order to awaken as early as possible in children an extensive sense of humanity, to give them a view of several sorts of insects as they may be magnified by the affluence of glasses, and to show them that the same evident marks of wisdom and goodness prevail in the formation of the minutest insect, as in that of the most enormous Leviathan: that they are equally furnished with whatever is necessary, not only to the preservation, but the happiness of their beings in that class of existence which Providence has assigned them: in a word, that the whole construction of their respective organs distinctly proclaims them the objects of the divine benevolence, and therefore that they justly ought to be so of ours.