350 



MUSEUM OF ANIMATED NATURE. 



[Insects. 



from the margins of the body, and in the end coveiii 

 the whole iiutect with a cell of this substar.ce, which, 

 when haixlened by exposure to the air, becomes lac. 

 So numerous are these insects and so closely 

 crowded together, that they ollen entirely cover a 

 branch, and the groups take different shapes, as 

 •quare, hexagon, &c., according to the space left 

 round llie insect which first began to form its cell ; 

 under these ceils the females deposit their eggs, 

 which alter a certain ptriod are hatched, and the 

 young ones eat their way out. Though indisputably 

 an animal secretion, many of the properties of lac 

 are not very different from the juices of the trees on 

 which the insect feeds, and which therefore would 

 seem lo undergo but little alteration." It may be 

 added that the parent, after depositing her eggs, 

 becomes glued to the spot and dies, covering the 

 germs of her progeny. Lac is an important export 

 from India, and is much used in this country in the 

 composition of varnishes, japanning, sealing-wax, 

 ice. It is called stick-lac when unseparated from 

 the twigs on which it adheres ; seed-lac when sepa- 

 rated and pounded, the colouring matter being ex- 

 tracted by water ; and shcll-lac when strained and 

 allowed to harden in the form of thin flakes. Its 

 colouring-matter is termed lac-lake, and a still su- 

 perior preparation is known as lac-dye, and used as 

 a dye cither conjointly with cochineal or by itself. 



"The Cochineal (Coccus cacti), like the rest of 

 this tribe, is closely allied to the Aphides, and feeds 

 on the succulent shoots of a species of fig, called, in 

 Mexico, nopal, and of which plantations are made 

 for the sake of the insect product. According to 

 Kirby and Spence, the cochineal is '• chiefly cul- 

 tivated in the Intendency of Oaxaca : and some 

 plantations contain sixty thousand nopals in lines, 

 each being kept about lour feet high, for more easy 

 access in collecting the dye. The cultivators prefer 

 the more prickly varieties of the plant, as aftording 

 protection to the cochineal from insects, to prevent 

 which from depositing their eggs in the flower or 

 fruit, both are carefully cut off. The greatest quan- 

 tity however of cochineal employed in commerce 

 is produced in small plantations belonging to 

 Indians of extreme poverty, called Nopaleros. 

 They plant their nopaleros in cleared ground in the 

 slopes of mountains and ravine.;, two or three 

 ]eaj;ues distant from the vilhi'^es, and when pro- 

 perly cleaned the plants are in a condition to main- 

 tain the cochineal in the third year." Three 

 gatherings of the insect take place usually in the 

 coui-se of the year; they are brushed off the twigs 

 by means of squirrels' tails, or similar instruments, 

 and are killed by exposure to the heat either of the 

 sun or of ovens. It has been calculated that the 

 annual consumption of cochineal, or the dried in- 

 sect, amounts to about 750 bags, that is 150,000 

 pounds, worth about 370,000/. Our readers will, we 

 trust, pardon this digression respecting the Coccus 

 cacti, of which Figs. 3459 and 3-100 give the repre- 

 sentation : fl, the winged male; h, the wingless fe- 

 male (magnitied). Fig. 3461 exhibits the eggs of 

 a species of coccus, invested with the down, which 

 appears to be either secreted by the parent from 

 pores in the skin, or excluded with them. Over 

 each group of eggs is the body of the parent, glued 

 fast and withered. They appear on the bark like so 

 many nodes or excrescences, and might be easily 

 mistaken for vegetable galls. 



A species of coccus in our island infests the 

 hawthorn and other trees, and places its group of 

 eggs in oval cells at the divarication of the twigs 

 or spines. These' eggs are orange-coloured, and 

 covered by the skin of the parent dried and 

 shrivelled, and which is glued tightly over them. 

 There are also several other species, some to be 

 found on the hawthorn, others on the vine, on cur- 

 rant-bushes, &c. The eggs constitute a source of 

 supply in winter to the titmouse, the hedge-sparrow, 

 and the golden-crested wren. 



Fig. 3462 represents the eggs of the Hawthorn 

 coccus covered by the dead body of the parent : 

 a, b, c, the groups of eggs ; d, one of the cells mag- 

 nified ; e, a section showing the eggs within. 



We may now pa.ss to insects which deposit their 

 eggs either in cavities on the ground, in the sub- 

 stance of plants, or of animal bodies, and for this 

 purpose are provided with a special instrument, 

 variously modified, termed the ovipositor. 



It is by means of a stout and powerful ovipositor 

 that the field-crickets, grasshoppers, and locusts 

 bury their eggs in the earth, where the larvse, 

 when hatched, find, in the roots of grasses and 

 herbage, abundant food. The ovipositor of these 

 insects is straight, and consists of two upper and 

 four lower blades, which together form a very effi- 

 cient instrument ; this inserted into the ground con- 

 veys the eggs safely to their destination. Fig. 3463 

 represents the spotted grasshopper of Europe (Tet- 

 tigonia verrucivora) in the act of depositing its 

 eggs. The dotted line shows the ordinary position 

 of the ovipositor. 

 Fig. 3464 shows the eggs of the green grasshop- 



per, Tettigonia viridissima (.\crida viridissiraa). 

 The insect's ovipositor is in the ordinary position. 

 We need not say that these ovipositors are not 

 I>resent in the stridulous males. 



An allied insect, the mole cricket (Grillotalpa 

 vulgaris), deposits her eggs in a different method. 

 This insect mole is well known in some parts of 

 I England, and commits in lawns, gardens, and fields 

 no little havoc ; it bores into the earth, excavating 

 long galleries, in which it lives ; its fore-limbs are 

 [ admirably adapted for the laborious operations it 

 carries on, being short, thick, and palmated at the 

 termination ; their muscular power is enormous, 

 and their action in shovelling the earth is the same 

 as in its mammal representative ; and they have, 

 moreover, the same oblique toumure. These in- 

 sects appear to live in small societies ; and we have 

 seen a patch of moist ground in which their bur- 

 rows were very numerous. This insect has been said 

 to devour the roots of herbage — and certainly it cuts 

 them asunder, but this jt apparently does, in order 

 to carry out its superficial galleries, while in pur- 

 suit of worms, ants, and other underground insects. 

 The nest of the mole-cricket, in which the female 

 deposits her eggs, is a smooth excavation at no 

 great distance underground from the surface. 

 Latreille says that she lays her eggs in June or 

 July ; but according to Gilbert White, much earlier. 

 "About the beginning of May," he says, " they lay 

 their eggs, as ' was once an eye-witness — for a 

 gardener at a hc*<se where I was on a visit, happen- 

 ing to be mowing on the sixth of that month by the 

 side of a canal, his scythe struck too deep and laid 

 open to view a curious scene of domestic economy : 



* Ingentem lato dedit ore fenestiam ; 

 Apporet domus intus; et atria longa patescunt 

 Appareut .... penetralia.* 



There were many caverns and winding passages 

 leading to a kind of chamber, neatly smoothed and 

 rounded, and about the size of a moderate snuffbox. 

 Within the secret nursery were deposited nearly a 

 hundred eggs of a dirty yellow colour, and en- 

 veloped in a tough skin — but too lately excluded 

 to contain any rudiments of young, being full of a 

 viscous substance. The eggs lay but shallow, and 

 within the influence of the sun, just under a little 

 heap of fresh-moved mould, like that which is raised 

 by ants." He informs us that " in fine weather 

 about the middle of April, and just at the close of 

 day, they begin to solace themselves with a low 

 dull jarring note, continued for a long time without 

 interruption, and not unlike the chattering of 

 the fern-owl or goat-sucker, but more inward." 

 Latreille says the song of the male, which is heard 

 only at evening and during night, is soft and rather 

 agreeable. 



Fig. 3405 shows the mole-cricket, with a separate 

 outline of one of its hands ; and Fig. 3460, the nest 

 of the same insect, with the eggs. 



Among the insects which bury their eggs in the 

 earth by means of an ovipositor, are the 'i'ipulse, or 

 crane-flies, so abundant in grassy meadows. The 

 ovipojitor is simple, bifid at the point, like a pair of 

 pincers, sharp, hard, and horny (see Fig. 3467). The 

 eggs are small and black, and of these each female 

 deposits several hundreds. The position she assumes 

 is very singular. Raising herself perpendicularly on 

 her two hind legs, and resting on the ovipositor, she 

 steadies herself by clinging with the other limbs to 

 the surrounding herbage ; she then thrusts the ovi- 

 positor in the earth to the first ring of the body, and 

 deposits a single egg; this doni she moves for- 

 wards, still maintaining her upright position, and 

 performs the same operation again; and so on till 

 the whole of her eggs are safely lodged in the 

 ground. The maggot, when hatched, attacks the 

 roots of grass and other herbage, and the ravages 

 which myriads of these caterpillars produce are often 

 very serious. They have frequently destroyed entire 

 fields of rising wheat and acres of verdant pastur- 

 age- , i 



A minute fly of the same family often proves even 

 more injurious ; we allude to the wheat-fly (Cecido- ' 

 myaTritici), which, bymeansofalong,slender,tubu- 

 lar and retractile ovipositor, deposits its eggs upon 

 the inner chaff, in which the furrowed side of the 

 grain is imbedded, fixing them by a glutinous secre- I 

 tion. They are occasionally placed in the interior I 

 parts of the flower and chaff. "A glutinous thread," i 

 says Mr. Shireff (Loudon's 'Mag. of Nat. Hist.' Nov. \ 

 1829), ■' frequently connects a cluster of eggs with i 

 the style, where the larvic seem to subsist on the 

 pollen ; in one instance fifteen eggs were numbered 

 on such a thread, several of which were suspended 

 on the portion extending between the chaff and the 

 style, 'i'he fly seems thus not only to provide a con- ' 

 veyance from the larvse to the style, but also food 

 for their support. The anthers are prevented from 

 leaving the style, in consequence of being gummed 

 down by the glutinous matter of the fly ; the pollen 

 is thereby detained for the use of the larvae, which 

 would otherwise be in part carried out of the glumes 

 by the expansion of the filaments, known to farmers 



by the term Uoom. In the exertion of gumming 

 down the anthers, many of the flies are entangled on 

 the vascules of the corolla, and thus become a sacri- 

 fice to their maternal affection. 



" The larvae are produced from ine eggs in the 

 course of eight or ten days ; they are at first per- 

 fectly transparent, and assume a yellow colour a few 

 days alXerwai-ds. They travel not from one floret to 

 another, and forty-seven have been numbered on one. 

 Occasionally there are found on the same floret larva; 

 and a grain, which is generally shrivelled as if de- 

 prived of nourishment ; and although the pollen may 

 lurnish the larvse with food in the first instance, they 

 soon crowd around the loweir part of the germen, 

 and there, in all probability, subsist on the matter 

 destined to form the grain." They appear to pass 

 the winter in the earth in a pupa state, leaving the 

 ears of wheat at the latter part of July. These cater- 

 pillars are happily very subject to the attacks of two 

 species of ichneumon-fly, which deposit their eggs 

 in the body of their victim, on which the future 

 larvae subsist. Were it not for this check to the in- 

 crease of the wheat-fly, its multiplication would be 

 most alarming. 



Fig. 3469 represents the germination of a grain of 

 wheat : a, the heart of the grain, the part devoured 

 by the larva; b, the bag of the seed; c, the root; 

 d, vessels to convey nutriment ; e, e, feathers con- 

 veying the pollen to fructify the seed. 



Fig. 3470 shows the female wheat-fly : a, greatly 

 magnified; A, larvae, of the natural size, feeding : c, 

 one of the larvae, magnified. 



An allied but rather larger species, the Hes- 

 sian wheat-fly (Cecidomya destructor), has committed 

 extensive ravages in America. It was first observed 

 in 1776, at Long Island, in the wheat-fields, whence 

 it spread gradually, and in 17«s had extended its 

 range two hundred miles from its original locality. 

 These flies literally appeared in clouds, and such 

 vyere seen crossing the Delaware, to the consterna- 

 tion of the country. The panic reached England, 

 and the subject engaged the earnest attention of the 

 Privy Council, for great was the probability that the 

 insect might be imported, when the most disastrous 

 consequences were to be anticipated. The female 

 Hessian fly, so called from an erroneous impression 

 that it was conveyed into America among straw by 

 the Hessian troops from Germany, deposits from one 

 to ten or twelve eggs in a single plant of wheat, 

 between the sheath of the inner leaf and the stem 

 nearest the roots ; and in this situation the larva, 

 with its head towaids the root or first joint, passes 

 the winter, and eating into the stem, causes it to 

 break, and at once destroys all chance of bearing 

 grain. It is easy to conceive the results of the descent 

 of a cloud of these flies over the corn-lands of Kent 

 or Essex. A fly, known in our own country, the Mark- 

 wick fly (Chlorops pumilionis), the larva of which 

 eats into and destroys the stems of wheat, was erro- 

 neously regarded by Mr. Markwick as identical with 

 the terrible Hessian fly, and his published observa- 

 tions respecting it caused no small consternation 

 among the agriculturists. It would appear that it is 

 only the early wheat sown in October that is liable 

 to injury from its visits. At Fig. 3471 both insects 

 are represented : a, the Hessian fly (Cecidomya de- 

 structor) ; b, the Markwick fly (Chlorops pumilionis) 

 magnified. 



All are acquainted with those little white mag- 

 gots, or larva, so common in cheese, and known by 

 the name of hoppers ; they are the products of a 

 minute black fly, with whitish wings margined with 

 black, termed the cheese-fly (Piophila casei). This 

 insect, by means of a retractile ovipositor of great 

 length, is capable of penetrating to a considerable 

 depth into the cracks and fissures of the cheese, 

 where it deposits its eggs, between two and three 

 hundred in number. In a few days these are 

 hatched, and commence their depredations. Swam- 

 merdam says that the decay of the cheese is really 

 caused by these maggots, for they not only crumble 

 the substance of it into small particles, but moisten 

 it with some sort of liquid, so that the decay rapidly 

 spreads. The .cheese-hopper is destitute of limbs, 

 but is provided with two stout horny jaws, which 

 it uses both for digging into the cheese and dragging 

 itself onwards. On being exposed by the breaking 

 up of its retreat, this maggot endeavours to escape 

 by the most astonishing leaps, which, the animal 

 being without feet, are performed in a very singular 

 manner. The larva first raises itself upon its tail, 

 which is furnished with two projections, to enable it 

 lo assume and maintain an upright position. It 

 then bends itself, arching its body in the form of a 

 circle, and lays hold of the skin of the tail with its 

 mandibles ; it now contracts with all its energy from 

 a circular into an oblong form, and with a sudden 

 jerk assuming a straight line, propels itself to a con- 

 siderable distance. 



The breathing tubes, or spiracles, of this cater- 

 pillar are not placed, as in ordinary cases, along the 

 sides, near the head, and near the tail, a pair being 

 situated at each part ; and it is said by Swammer- 



