1070 PRACTICE OF AGRICULTURE. ' Part III. 



constituting one of the heaviest afflictions that can happen to a country. The mischiefs done by the 

 blattffi, or cock-roaches, is trifling compared with -4;hose of this destroying tribe, for the dreadful ra- 

 vages committed by the locusts are such as to reduce the most fertile fields to the appearance of barren 

 deserts j they devour the fruits, leaves, and even the buds and bark of trees, and have even been 

 known to devour the reeds used in thatching the hurhan habitations, so unfortunate as to be visited 

 by these devouring hordes. Jackson depicts their ravages in the empire of Morocco, and gives a figure 

 of the insect {fig. 755.) of half the natural size. In 

 Abyssinia, China, and other countries, the caterpillar 

 or larva of certain species of roaches and locusts is, like 

 that of some beetles, eaten by the natives. 



6882. A species of grasshopper apparently peculiar 

 to New England is mentioned by Dr. Dwight, as 

 appearing periodically. He says, " As I had no op- 

 portunity of examining them, I cannot describe their 

 form or their size. Their favorite food is clover 

 and maize. Of the latter, they devour tlie part which 

 is called the silk, the immediate means of fecundating 

 the ear, and thus prevent the kernel from coming to 

 perfection. But their voracity extends to almost every 

 vegetable, even to the tobacco plant and the burdock. 

 Nor are they confined to vegetables alone. The gar- 

 ments of laborers, hung up in the field while they are 



at work, these insects destroy in a few hours, and with the same voracity they devour the loose particles 

 which the saw leaves upon the surface of pine boards, and which, when separated, are termed saw-dust. 

 The appearance of a board fence, from which the particles had been eaten in this manner, and which I saw, 

 was novel and singular, and seemed the result, not of the operations of the plane, but of attrition, the cause 

 of which I was unable to conjecture. At times, particularly a little before their disappearance, they 

 collect in clouds, rise high in the atmosphere, and take extensive flights, of which neither the cause 

 nor the direction has hitherto been discovered. I was authentically informed in Shaftsbury, that some 

 persons, employed in raising the steeple of the church in Williamstown, were, while standing near the 

 vane, covered by them; and saw at the same time vast swarms of them flying far above their heads. 

 The customary 'flight of grasshoppers rarely exceeds four or five j^ards, and their wings are apparently 

 so weak as to forbid excursions extended much beyond these limits. It is to be observed, however, that 

 they customarily return, and perish on the very grounds which they have ravaged." [Dimght's Travels, 8cc. 

 vol. ii. p. 385.) 



6883. The frog-hopper, or cuckow-spit insect, {Cicada), feeds on various kinds of plants; the grub or 

 larva is without wings ; in the pupa the wings are very short; but in both states they are exceedingly 

 active. The males are distinguishable by their loud chirping note, the females are quite mute. In the 

 fly state, they are found on the leaves and stems of plants, and irt the immature state about the roots of 

 grass and trees. The white froth-like spittle, which is seen on the leaves and stalks of many kinds of 

 plants in the summer season, is produced by the black-headed frog-hopper {Cicada spumaria,fig. 754 b), 

 and if this froth be wiped off and examined, it will be found to contain the larva or young of the cicada : 

 and this matter, which is discharged from its own body, no doubt serves to protect it from the attacks of 

 other insects. 



6884. Jfte ptoraf-ZoMse, vine-fret ter, or puceron," (Jj9/5) is a very common insect, the numerous species 

 being denominated from the trees and plants which they infest. The males are winged, and the females 

 without wings ; they are viviparous, producing their young alive in the spring: and also oviparous, lay- 

 ing eggs in the autumn. As these insects derive their nourishment from the juices of the plants which 

 they infest, nature has wisely ordained that the females should lay eggs in the autumn, though 

 they bring forth their young alive all the spring and summer months. This is to prevent them from 

 being starved for the want of food in winter. The young burst forth from their eggs in spring as soon as 

 there are leaves to subsist upon. Their noxious effects are well known to the gardener. They sometimes 

 migrate, and suddenly fall in showers on spots that were until then free from their ravages. Water 

 dashed with force from a syringe will prove as destructive to them as any thing when on trees ; and 

 smaller plants may be washed with lime-water, with tobacco-water, with elder leaves infused in water, or 

 with common soap-suds, any of which will destroy the insects. The larvae of the lady-hird eat thousands 

 of them, some species of ichneumon and common ants also destroy them ; and some conjecture that it 

 would probably prove serviceable to scatter ants, which may always be procured in abundance, upon in- 

 fested trees. The aphides sometimes settle upon the tops of beans, covering them so thickly as to make 



tops, a practice 

 increasing the 

 yield of beans. {Dr. Skrimshire's Essays, Tntrod. to Nat. Hist., vol. i. p. 149.) The rose-tree is, after a 

 mild spring, greatly injured by a species of aphis {A. rosce). The best mode of remedying this evil is'to 

 lop off the infected shoots before the insects are greatly multiplied, repeating the same operation be- 

 fore the eggs are deposited. By the first pruning a very numerous increase will be prevented, and by 

 the second, the following year's supply maj^ in a great measure, be cut off! If it were not for the 

 numerous enemies to which the aphis is exposed, their wonderful fecundity is such that the leaves, 

 branches, and stems of every plant would be totally covered with them. Myriads of insects of different 

 classes, of different genera, and of different species, seem to be produced for no other purpose than to 

 devour the aphis. On every leaf inhabited by them we find caterpillars of different kinds. These 

 feed not upon the leaves, but upon the pucerons, whom they devour with an almost incredible rapacity. 

 Some of these larvas are transformed into insects with two wings, others into flies with four wings, and 

 others into beetles. While in the larva state one of these glutinous insects will suck out the vitals of 

 twenty pucerons in a quarter of an hour. Reaumur supplied a single caterpillar with more than a 

 hundred pucerons, every one of which it devoured in less than three hours. 



6885. The chermes {fig. 154: c, d, e.) is a genus very generally confounded with aphis ; it also inhabits 

 the leaves and stems of plants, and by its punctures, produces excrescences and protuberarrces of various 

 sizes and shapes, which are generally found to enclose either the egg or immature insect, in the larva 

 state ; it is six-footed, hairy or woolly, and without wings ; and in the pupa are two protuberances from 

 the thorax, which are the rudiments of the future wings. The winged insects (c) leap or spring with great 

 agility, and infest a number of different trees and plants : the females {d); by means of a tube at the ter- 

 mination of their bodies, insert their eggs under the surface of the leaves ; and the worms, when hatched, 

 give rise to those tubercles, or galls, with which the leaves of the ash, the fir, and other trees, are some- 

 times almost entirely covered. The old females, before depositing their eggs, expand to a comparatively 

 large size (e). 



6886. The thrips genus {fig. 754/. ) consists of very small insects, found chiefly on the flowers of plants, 

 and, excepting when very numerous, are not very detrimental. The natural size is very minute, and 

 therefore to search for this insect a magnifying glass is required. 



6887. Of the cochineal or coccus genus {fig. 754 g.) there are several species very injurious in gardens, the 

 peach, vine, pine, and orange bugs. They are very well known to gardeners, and are almost exclusively 

 found in hot-houses. The males are active, but the females are very inert, being generally fixed to differ- 

 ent parts of plants. The eggs, of their natural size, are mere dots, magnified {g) they appear of an oval 

 shape ; the larva is proportionally small, but magnified {h) is oblong and roundish ; the males {i) only have 

 wings, and require to be magnified to show their form (A) ; the female attains a considerable size (/), and. 



them appear quite black : in such cases the crops may often be preserved by cutting off the tc 

 which is likewise adopted, independently of this pest requiring it, for the purpose of ii 

 yield of beans. {Dr. Skrimshire's Essays, Tntrod. to Nat. Hist., vol. i. p. 149.) The rose-t 



