Part 37

[1490] Dejean in his catalogue gives only 434 species; while Mr. Stephens, _four_ years ago, had 550, and has since increased the number to above 600.

[1491] _Journal of a Tour in Iceland_, 272.

[1492] VOL. I. p. 115--.

[1493] _Entomogr. Russ._ Coleopt. _t._ xiii. _f._ 1.

[1494] Ahren's _Fn. Europ._ i. 1.

[1495] _Hor. Ent._ 47--.

[1496] _Annulosa Javanica_, 36.

[1497] See the Rev. L. Guilding's admirable _History_ of _Xylocopa Teredo_ and _Horia_ (_Cissites_ Latr.) _maculata_, Linn. Trans, xiv. 313--.

[1498] Out of 51 species described by Bilberg, 28 are African, and 19 of these are from the Cape.

[1499] _Géogr. Génér. des Ins._ 18.

[1500] _Hor. Entomolog._ 45.

[1501] Dr. Leach has described 8 British species (_Linn. Trans._ xi. 37.); Dejean has 7 Spanish ones.

[1502] I have a very splendid species of this genus taken by C. C. Elwes Esq. on the Pyrenees, which is undescribed, and falls under none of the count Dejean's Families, having its elytra perfectly smooth, without striæ, punctures, &c. It is of a brilliant golden green. It stands in my cabinet under the name of _C. lævigatus_. K.

[1503] Fischer _Entomogr. Russ._ 90--. _t._ viii. _f._ 13.

[1504] VOL. III. p. 562.

[1505] Major General Hardwicke gave me one of this description from Nepal.

[1506] Latr. _Géograph._ &c. 18--.

[1507] _Linn. Trans._ xiv. _t._ iii. _f._ 4.

[1508] _Hor. Entom._ 147.

[1509] _Linn. Trans._ ubi supr. _f._ 1.

[1510] _Ibid._ xii. _t._ xxi. _f._ 9.

[1511] _Ibid._ _f._ 14.

[1512] To this genus belong _Melolontha aurulenta_. Ibid. 400; and _M. sericea_. Ibid. 463.

[1513] Latr. _Géograph._ 7.

[1514] _Cetonia atropunctata_ and _Brownii_ of _Linn. Trans._ (xii. 464. _t._ xxiii. _f._ 6.) belong to this genus.

[1515] _Linn. Trans._ xii. _t._ xxii. _f._ 2; _t._ xxiii. _f._ 7.

[1516] Latreille, _Géograph._ &c. 10.

[1517] _Linn. Trans._ xiv. 569.

[1518] See above, p. 496.

[1519] Fischer, _Entomogr. Russ._ i. 135.

[1520] From finding it in water, Fabricius considered this insect as a _Hydrophilus_, but it is a true _Cercyon_.

[1521] See above, p. 401.

[1522] _Personal Narrat._ E. T. v. 91--.

[1523] See VOL. I. p. 470--.

[1524] A species of _Gyrinus_ (_G. Viola aquatica_), described by Modeer (_Linn. Syst. Nat._ Ed. Gmel. i. 1612. n. 9.), is said to inhabit _salt_ water.

[1525] _Géograph._ &c. 6.

[1526] _Apis_ *., a. _Mon. Ap. Angl._ ii. 178--.

[1527] _Linn. Trans._ iv. 30--. v. 96--. _t._ iv.

[1528] VOL. I. LETTER VI.

[1529] _Géograph._ &c. 6.

[1530] VOL. II. p. 255.

[1531] These, as well as _Melecta_, are probably a kind of _Cuckow_-bee. _Mon. Ap. Angl._ i. 150.

[1532] _Melitta_ * *. b. _Mon. Ap. Angl._ i. 138--.

[1533] _Mémoires sur le gènre_ Halicte.

[1534] VOL. II. p. 9.

[1535] _Linn. Trans._ ix. 78--. _t._ i. _f._ 20.

[1536] _Ibid._ 55. _t._ i. _f._ 12.

[1537] This insect does not, I believe, eat the petals of the rose, but _laps_ the nectar it produces. I have seen it employed upon wounded trees lapping the sap.

[1538] _Mon. Ap. Angl._ ii. 172. 257.

[1539] See above, p. 491, note^a.

[1540] _Ibid._ p. 219; and VOL. I. p. 267--.

[1541] _Ibid._ p. 256--.

[1542] _Apis_ * *. e. 2. K.

[1543] _Apis_ * *. c. 2. α. K.

[1544] _Butterfly Collector's Vade Mecum_, 66, note^d.

[1545] De Geer ii. 638--. 641--.

[1546] Swamm. _Bibl. Nat._ i. Conf. 114 with 103.

[1547] Reaum. vi. 480--.

[1548] VOL. II. p. 11.

[1549] _Lepidopt. Britann._ 263--.

[1550] _Linn. Trans._ v. 256.

[1551] VOL. II. p. 95--.

[1552] See above, p. 254--.

[1553] VOL. II. p. 217. See above, p. 200.

LETTER L.

_ON ENTOMOLOGICAL INSTRUMENTS; AND THE BEST METHODS OF COLLECTING, BREEDING, AND PRESERVING INSECTS._

Having in my last letter given you some account of the _haunts_ of insects, I now proceed to describe the various _instruments_ with which you ought to be provided, to enable you to collect them; and the best mode of employing each. The Entomologist when he makes an excursion should have _three_ principal objects in view, for which he ought to be duly prepared. The first is to _find_ insects, the next is to _catch_ them, and the last when taken to bring them _safe_ home. In exploring their haunts he must also recollect that some will be _reposing_; others _feeding_; others _walking_ or _running_; others _flying_; others _swimming_; others _lurking_ in various places of concealment, and in _different_ states of existence; and that he must be prepared with means of coming at and capturing them under all these circumstances.

1. First furnish yourself with a strong _knife_ or other instrument with which you can raise the bark or penetrate the wood of any tree, when circumstances indicate that insects are busy below the one or within the other. There is no better tool for this and other purposes than Mr. Samouelle's _digger_, which consists of an iron five inches long, rather more than one-third of an inch in diameter, forming a curve towards the extremity, terminating in a lozenge-shaped point, and strongly fixed in a wooden handle[1554]. With this you may not only explore the interior of timber-trees, but grub up the turf under them, and examine the earth for the pupæ of _Lepidoptera_. When your object is merely this _latter_ purpose, a potato-fork--which is better than a spade, as it will seldom injure the pupæ--will be your best implement.

2. Next have a _stick_, to resemble a common walking-stick, sufficiently stout to beat the branches of the trees and shrubs, fitted at one end with a male screw, and at the other with a female, with a brass cap to screw over each to keep the dirt from them. Besides this, you may carry with you a spare piece or two about a foot long, properly equipped to screw to it when you want to lengthen it.

3. Another implement must be a _bag-net_[1555]. This consists of a hoop of stout brass wire about nine inches or a foot in diameter, with a socket to receive the end of your stick, or, what is more secure, a screw to fix it to it, with a bag of gauze, muslin, or fine canvass, about twelve inches deep, sewed round it. The French collectors use a net of this kind, in which the hoop is formed of two semicircular pieces of iron or brass wire hooked together at one end, and at the other made to lap over the corresponding piece, and pierced to receive the screw at one end of your stick. When not employed, they double the hoop and conceal it under the vest; they fix to it a muslin bag of two feet long. This net is made to serve various purposes. With it they catch _Lepidoptera_ and other _flying_ insects; and an adroit collector by giving it a certain twist completely closes the mouth, so as to prevent the escape of his captives. Fixed to a very long pole (Mr. Haworth says it should be _twenty_ or _thirty_ feet long[1556]), it is the best net for the purple emperor butterfly (_Apatura Iris_). It is also used with success to _push_ before you through the _grass_ of meadows, woods, &c., and thus often displaces numerous insects, which fall into it;--every now and then it is examined, and the valuable captures secured. The common bag-net will perform the same operations, but is not deep enough for _flying_ insects. If you lengthen your stick before you screw it on, it enables you to brush with it the weeds at the sides and bottom of ditches. This employment of brushing the grass, &c. may be carried on if you are walking with any friend not interested in Entomology, without much interruption of conversation. For this last operation--sweeping the grass, &c.--if you wish at any time to devote a morning wholly to it, you will find a net invented by the late Mr. Paul, of Starston in Norfolk, and which he employs to clear his turnips of _Haltica Nemorum_[1557], a very useful implement. The accompanying figure will give you a better idea of it than any description[1558]; you may make it large or small according to your convenience: the wider it is, the greater space it will brush at once. When your object is a more general investigation, the bag-net just described is preferable.

4. Scarcely any implement seems a greater favourite with British collectors than what may be called the _fly-net_[1559]. This is universally employed by them for capturing _flying_ insects, especially _Lepidoptera_. It is similar to what is called a _bat-fowling_ net, and should be made of green or white gauze or coarse muslin. The _former_ colour, as being less visible, is most proper for _mothing_ in the _night_; but the _latter_ is best for the _day_, as this net is useful to hold under the branches of trees and shrubs to receive the insects that fall when they are beaten. The rods for the net we are considering,--which should be about five feet long, half an inch in diameter at the base, and gradually tapering to the end,--must be made of some tough wood; each should consist of about four joints for the convenience of carriage, and each joint should be fitted with a socket at the lower extremity, to receive the top of the joint below it: the terminal joint must either be bent into a curve, or fitted with an angular socket or ferrule, so as to form an obtuse angle with the rest of the rod[1560]. The gauze which is to form the net, being cut into the requisite shape, should be welted round, except at the bottom, where it should have a deep fold or a bag for preventing the escape of the included insects--in order to form a slide for the rods to slip in. At the apex where they meet, a few stitches should be set, or a piece of leather sewed in, to prevent their going too far. At the bottom, on each side, two strings must be sewed on the net, to receive which there must be a hole in each rod about six inches from the bottom: these must be tied, which will keep the net from slipping upwards. When you go after moths and other insects that fly in the _night_, a plan, as I am told, of some of the London collectors may be adopted with advantage. Cause a lanthorn to be made with a concave back, and furnished with a reflector: this must be fastened, by means of a strap, upon the stomach. If you hold your expanded fly-net before this (as nocturnal insects fly to the light), you may thus entrap a considerable number. In sultry summer nights also, if you place a candle on a table in a summer-house, or even in a common apartment, and open the windows, you will often have excellent sport, and take insects you might otherwise never meet with.

When you use your fly-net, you must take the rods one in each hand, so as to keep it extended; and when you have brought it fairly beyond the insect you are pursuing,--to accomplish which you must be upon the alert,--you must bring the two sticks together, which, if you are commonly dexterous, will capture your prey. This net is likewise useful in taking winged insects when at rest upon the ground, by simply spreading it over them. When you use it to beat into, as above recommended, you must take both the sticks in one hand, and extend it by crossing them as much as you can. In the absence of this, a common umbrella, or even a sheet of stiff paper which you may carry folded in your pocket, are no bad substitutes. When your object is _beating the bushes_, bring your fly-net, &c. rapidly under the branches you mean to operate upon, or the insects will fall from them to the ground before you are prepared.

Under this head I may mention a very ingenious net for taking _Lepidoptera_, particularly _butterflies_, invented by Dr. Maclean of Colchester, which I would call _Maclean's elastic net_. It is constructed of two pieces of stout, split cane, connected by a joint at each end and with a rod which lies between them, in which a pulley is fixed; through this a cord fastened to the canes passes; a long cane with a ferrule receives the lower end of the rod and forms a handle; and to the canes is fastened a net of green gauze. Taking the handle in your right hand, and the string in your left, when you pull the latter the canes bend till they form a hoop, and the net appended to them is open; when your prey is in it, relax the cord, and the canes become straight and close the mouth of the net, keeping them close with your left hand, you may soon disable your prey with your right. Dr. Maclean has scarcely ever found this net fail.

5. Another instrument which should be constantly in the hands of the Entomologist is the _forceps_[1561]. This is particularly useful for catching _Diptera_ and _Hymenoptera_ chiefly while at rest on the leaves and flowers of plants. Both these tribes are usually too agile to be taken by the hand alone, which besides without this contrivance would be exposed to the stings of many of the latter. The leaves of the forceps should be _octagonal_, five or six inches in diameter, and covered with green gauze, or rather very fine catgut, which will enable the head of a lace-pin to pass through it. You must direct your artisan to make the joint of the handle nearer the rings for the finger and thumb than to the leaves, or the instrument will not open well. An old pair of curling-irons might be made into very good handles; but the hoop to which the catgut is fastened should be brass, or if iron it ought to be painted to secure it from rust. Some make the leaves of the forceps _round_; but when an insect is perched on a wall or any _vertical_ surface, it has less chance of escape if you can apply a straight side to its station. The Germans use a much longer and larger instrument of this kind, having leaves of ten or twelve inches in diameter, which they use to catch _Lepidoptera_ when settled on plants. When you aim at an insect with your forceps, you must expand the leaves as much as possible, and cautiously approach your prey; and when within reach, close them upon it suddenly, including the leaf or flower on which it rests. As these are sometimes bulky, and prevent the instrument from shutting closely,--that the included insect may not escape, it is often necessary to use the other hand to bring them together, when the pressure of the finger and thumb soon disables it.

6. As the _waters_, whether running or stagnant, as well as the earth and the air, teem with insects, you must likewise be provided with a net of a different description from any of the preceding, that you may _fish_ them out. It may be made of fine canvass, just deep enough to prevent the insect from jumping out, and fastened to a brass hoop five or six inches in diameter, not perfectly circular, but having the segment of a circle cut off anteriorly, so that it will apply well to a flat vertical surface; and fitted posteriorly with a socket, to receive the end of your stick; or, what is better, with a _screw_, which will securely fasten it to it[1562]. In using this net, different modes may be adopted. You may either watch the motions of an individual insect, and secure it by darting the net beyond it and drawing it towards you; or by placing it quietly under it, and then elevating it suddenly; or you may push your net at random along the margins of the pools and rivers amongst the weeds, &c.; amongst the duck-weed (_Lemna_) on their surface, or the mud at the bottom; and when you examine its contents, you will often find valuable captures. I have thus sometimes got rich booty in the most unlikely places;--such as _Hydræna longipalpis_, and an allied nondescript species, &c.; and by fishing amongst _Zanichellia palustris_, _Hæmonia Zosteræ_. If at any time you do not happen to have your water-net with you, with a common rake you may take the duck-weed from the surface of a pool, and upon examination you will often detect amongst it many minute water-beetles.

But besides all these implements you will find your _finger_ and _thumb_ a very _handy_ forceps when insects are stationary or walking upon the ground; and even when flying, minute ones that you would not otherwise meet with may be taken by the palm of your hand, wetted with saliva, if, when you see them swarming in the air, you pass it to and fro amongst them. When such are stationary, or moving on the ground, on rails, the trunks of trees, &c., the fore-finger, so wetted, will often best secure them: but if they are perched on a summit or a vertical surface, before you approach near enough to alarm them bring forward quietly your bag-net, and hold it so that they may fall into it, if they attempt by falling to escape you. Other methods of entrapping insects may also be pursued with success. A table-cloth spread on the grass in the open parts of a wood I have known allure several scarce insects: a lady's white dress is equally attractive. An old mattress, laid at night upon a grass-plat, if suddenly reversed in the morning, will supply the Entomologist occasionally with good _Coleoptera_. No better trap for the _Silphidæ_, _Dermestidæ_, &c., than a piece of carrion, a frog, or mole, &c. The numerous insects that inhabit excrement of every kind, especially that of the cow and the horse, may be best taken by immersing their pabulum in water: for this purpose, let a boy carry a spade and pail to the scene of action, and filling the pail nearly full of water begin the operation, and all the insects lurking in the submerged dung will come to the surface, and may be easily taken.

Another object of the collector of insects, when he has once entrapped them, is to bring them _safe_ home. The Entomologists on the Continent, I believe, generally transfix their prey, of whatever Order, with a pin, as soon as they are caught: but as _hard_ ones, such as _Coleoptera_, _Hemiptera_, &c., may be destroyed without injury by immersion either in spirits of wine or boiling water; and as large beetles, if transfixed (not to mention the unnecessary cruelty of so serving them), are apt to whirl round upon the pin in spite of any precaution, and injure themselves, and destroy other insects that are in their way, it seems best to kill them by other more effectual methods. With regard to those that would be injured by immersion in any fluid, as the _Lepidoptera_, _Hymenoptera_, _Diptera_, &c., they must be secured as soon as taken; and after having disabled them as much as you can without injuring them, by pressing the trunk below the wings with the finger and thumb, they should be transfixed and put into a pocket-box lined with cork. Some use an oblong deep chip one, with paper pasted over it, and lined at top and bottom, the top being convenient for setting small moths. But this you will find not easy to open when you have an insect in one hand; and it is too deep for the pocket. I generally use a mahogany one, about 7-1/2 inches by 4-1/2 and 1-1/4 deep in the clear, corked only at the bottom, and opening by pressing a spring, which can be done with one hand. This will contain as many of the above insects as you will usually take in a day's excursion. When travelling, you should provide yourself with larger store-boxes, to receive at night the fruit of the day's hunt. These may be 18 inches square and 2-1/2 deep, corked at top and bottom; which should be of equal depth, and fit very closely, to keep out _Acari_, &c. Entomologists have recourse to various ways of bringing home insects for immersion. For the larger ones, you must be provided with a number of small boxes, the lids of which are not liable to come off in the pocket. If it can be done, it is best to have only a single insect in a box. If you have several, those that are predaceous in their habits will probably devour the rest: and besides, if you open a box to put in other insects, generally one or two of those before imprisoned in it will make their escape. It is best to put the boxes containing an insect in one pocket, and the empty ones in another. If your boxes are numbered, in a small memorandum-book, which you should carry for the purpose, you may make any remarks as to the food, station, and habits of any insect you may take, inserting against them the number of the box or phial that contains it, and it will be ready for future use. For the smaller beetles, &c. a number of phials, with their rims ground down and the mouths well fitted with corks, must be provided; but for those you do not wish to keep separate, a wide-mouthed phial filled with spirits of wine, which soon kills them, is the best receptacle. I have found, when at a loss, a piece of elder, with the pith taken out to a sufficient depth at each end and each mouth stopped with a wooden plug, a useful insect box. As numerous insects inhabit the various species of _Boleti_, if you go where these are to be found, unless you are a very agile person and expert at climbing, a boy with a short light ladder will be no useless accompaniment.

Something may be said in this place upon the _dress_ with which the Entomologist should provide himself. I shall not recommend to you, in imitation of the insect-hunters in the vignette to Reaumur's second volume, to put on a bag-wig and a velvet court-dress; but the plain fustian jacket with side and other pockets used by English sportsmen will very well suit your purpose; only let the pockets be sufficiently ample: have also an inside one fixed on the left-hand side to receive your forceps. You may also have a bag like a shooter's, or an angler's basket, which may contain your nets till you want to use them. With all your implements about you, you will perhaps at first be stared and grinned at by the vulgar; but they will soon become reconciled to you, and regard you no more than your brethren of the angle and of the gun. Things that are unusual are too often esteemed ridiculous; and the philosopher whose object is to collect and study the wonderful works of his CREATOR, is often regarded by the ignorant plebeian as little short of a madman.