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thrust cautiously from the tube, and the garniture of the head is displayed so as to form a circle of miniature plumes of great elegance and delicacy.

The animal is scarcely an inch long, with a vermiform body of a reddish or flesh colour, the tint varying in intensity, according to its state of repletion. The head is truncated, and invested with a fine membrane divided in front and produced at the sides into angular points. On the upper and dorsal margin there are two dark, prominent, minute specks, something like eyes. From the anterior surface of the head originate the pectinated, or plume-like, branchiæ, collected into two bundles or tufts, but apparently forming a continuous circle when expanded. There are six branchiæ in each tuft, but it is rather difficult to ascertain the exact number: they are of a uniform yellowish colour. The mouth is inferior, and is encircled with not less than six tentacular filaments, of unequal length. Body tapered posteriorly, very distinctly annular; the segments shorter than their diameter, and armed on each side with a few short unequal bristles: a darker line down the middle marks the course of the alimentary canal, which runs straight from the head to the tail. Just below the head, and on each side of the intestine, there is a linearoblong organ of a dark colour, which is in a state of constant alternate contraction and dilatation; and which, therefore, I presume to be the heart propelling forward the circulating fluid.

The genus Sabélla occurs in the Systema Natura of Linnæus, who, having no distinct knowledge of the variety of the inmates, placed in it every tube composed of particles of sand and broken shells united to a membrane by a glutinous cement. As at present restricted and defined, the genus may be considered as having been instituted by Cuvier, whose name Lamarck has uncourteously changed to that of Amphi

trite. It is one of the most beautiful and remarkable genera among the sedentary Annélides; but the species now described differs from the typical species, in having more than two tentacular filaments at the mouth; so that the generic character of Cuvier and Lamarck will require some modification in order to the reception of it.

Berwick on Tweed, May 28. 1833.

ART. VII. A Notice of the Ravages of the Cane Fly, a small winged Insect, on the Sugar Canes of Grenada, including some Facts on its Habits; by a SUBSCRIBER in Grenada: with additional Observations, by J. O. WESTWOOD, Esq. F.L.S. &c.

Sir,

FOR these last six months [back from March 13. 1833] this island has been infested with a species of insect that threatens not only great injury to the present crop of sugar cane, but also to render the labours of the planter entirely abortive for the next crop. The Aphis, puceron, vinefretter, blight, or cane fly, as the insect is here termed by the planters, has long afforded an interesting study to the naturalist, and been a pest to the husbandman and gardener, and is too well known to require particular description. I am not aware that any species of insect hitherto noticed has been found so formidable, either in number or destructive qualities, as the cane fly, which is now propagating, and so rapidly overrunning the sugar plantations in this colony. I therefore hope the following particulars respecting it will not be altogether uninteresting to your readers, and that these particulars will draw forth some useful observations from those who may have had opportunities of witnessing the habits and ravages of this tiny destroyer of the cane, and who may, consequently, be able to throw some light on the most effectual method of extirpating it. The insect, formed with a snout and beak ending in a bristle, no doubt for the double purpose of depositing its eggs and extracting its food, attacks the cane in all the stages of its growth; but is more particularly injurious to plants or ratoons when they are young and tender. The under surface of the leaf, and towards the midrib, or the course of the larger sap-vessels, is selected by the insect for the scene of its operations. There it makes an oblique puncture, resembling that which would result from a lancet introduced in the same direction. Into

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each of these punctures from five to fifteen eggs are deposited; and each egg is placed transversely with respect to the direction of the fibre of the cane, which serves to overlap them, and thus afford a protection from the many enemies they have among the insect race. The aperture is then covered by a very light substance resembling that which protects the eggs and young of various species of spider (Arànea). This substance is always observed to be attached to the posterior part of the body of the insect, and to cover the two spines placed there, and which are characteristic of the genus. When the insect appears on the surface of the leaf after its first transformation, it seems dull and inactive, and is generally covered with a light floss of the substance already mentioned; but having changed its skin, which it leaves perfect and attached to the leaf, it becomes lively, active, and voracious, and joins in the work of propagation and destruction.

There can be no doubt, or at most but little, that the A'phides do not select the sugar cane merely as a medium for the deposition of their eggs, but that, like millions of other creatures, they also regale themselves with its sweets, and, from their numbers, literally bleed the plant to death. The Aphis sacchari, for such it ought to be called according to Linnæan nomenclature, like most of the tribe, produces in great abundance the substance called honey-dew, so much so, that the upper surface of the leaf infected is covered over with it. This substance, when dry, becomes black and of a light texture, which, being nearly insoluble in water, destroys or interrupts the action of the atmosphere, and aids in the general destruction of the plant.

This destructive insect, which might have, at first, been easily exterminated, has now overrun a great part of this island, and has baffled every attempt made to destroy its countless offspring. There is no doubt that, although they are new in this colony, they must have been known in many other parts of our tropical regions; and information on this point and on any other point of the subject will be much valued. Accompanying this, I send you specimens of the full-grown insect, with a specimen of the diseased leaf, and a magnified sketch (fig. 54. b) of the insect, in case of the loss of the insect itself. Although this species of the A`phis generally confines itself to the sugar cane (Saccharum officinàrum L.), like as other species of Aphis severally addict themselves to distinct species of plants, yet it may be worthy of notice that I have found it on the Paspalum distichum L., a grass of so opposite a nature, that it has here obtained the

name of sour grass, although the taste is more that of a bitter with a slight acidity, and, being avoided by cattle, horses, &c., is considered poisonous.

Grenada, March 13. 1833.

I am, Sir, yours, &c.

A SUBSCRIBER.

Additional Observations upon the Insect which infests the Sugar Canes in Grenada. By J. O. WESTWOOD, Esq. F.L.S. &c.

Sir,

As the circumstances detailed in the preceding communication, although here and there somewhat obscure, are of much interest in a commercial point of view, and as they add another species to a catalogue, already too extensive, of insect destroyers of the sugar cane, I trust that the following observations thereupon will not be deemed unacceptable.

The insect forming the subject of the preceding account, submitted to me for examination, proves, both from your correspondent's sketch, and from various specimens contained in the box of cotton accompanying his remarks, to be a Homopterous insect belonging to the Linnæan genus Cicàda, and to the subgenus Délphax as restricted by Latreille. Consequently your correspondent is in error in assigning to it the scientific name of an A`phis, although it is not improbable that persons unacquainted with entomology in the West Indies may have bestowed upon it, from its resemblance to the common plant lice, the French vernacular name of the A'phides, puceron. So also your correspondent appears to have gratuitously furnished the insect, in his description of it, with two spines, which, as to place, he has assigned to the posterior part of the body, but which, although characteristic of the genus A`phis, are not found in the specimens which he has himself forwarded of the insect in question, nor, indeed, in any of the Cicádidæ.

It does not appear quite clear in what manner the insect attacks the plants. Your correspondent, indeed, mentions "a snout and beak ending in a bristle," which he considers may be for "the double purpose of depositing its eggs and extracting its food." As, however, it is of absolute necessity that we should be perfectly acquainted with the peculiar modes of attack of our insect depredators, before we can think of proposing any effectual remedy for their destruction, it may be allowed me to endeavour, from the peculiar anatomy of these insects, from analogy, and from your correspondent's notes, to show the real cause of the mischief. Now, the

female of this insect, in common with all of the Cicádidæ, is furnished at the extremity of the body, beneath, with an admirably formed pair of saw-like organs, which are expressly for the purpose of cutting grooves in various vegetable productions, in which the eggs are then deposited. A full account of this apparatus is given by Reaumur: but, the A'phides not being furnished with it, their progeny is deposited upon the surface of plants. Where, therefore, the Grenada insect abounds, it is not improbable that much mischief may be occasioned by the interruption of the juices of the plants; but I can scarcely think that this (which is the chief complaint of your correspondent) can be the primary cause of the mischief. He, indeed, adds, although doubtingly, that the insects regale themselves upon the sweets of the sugar cane, and, from their numbers, literally bleed the plant to death. Now, the under side of the head of the insect in all the different stages of its life, is furnished with a jointed sucker having several fine internal darts ("the snout and beak ending in a bristle," of your correspondent), which it thrusts into the leaves or stems of plants, for the purpose of pumping up its fluids, which are its only nourishment; but in no instance of which I am aware is this kind of rostrum employed in forming a receptable for the eggs.

Many of your readers have, doubtless, often observed in the spring a quantity of frothy matter upon various plants. This is caused by an insect nearly allied to the Grenada pest, and is commonly known by the name of the cuckoo-spit insect (Aphróphora spumària). In this instance the frothy matter is nothing else but the sap of the plant which the insect has pumped up into its stomach by its snout, and afterwards ejected; and we can easily conceive, if any plant were to be attacked by myriads of this insect, how great would be the damage which it would sustain; the operations of this insect, from the similarity in the structure of the mouth, being very similar to those of the plant lice: and your readers are all aware how exceedingly detrimental some species of the latter genus (A`phis) are in England; one of them, A`phis hùmuli, often occasioning damage as serious to the grower of the hop as the Grenada insect does to the planter of the sugar cane.t

In the weevils (Curculionidæ), however, this appears to be the case, it being recorded that the nut weevil (Balaninus nùcum) pierces with its long snout the shell of the nut in which it deposits its eggs. (See, also, Rusticus of Godalming, in the Entomological Magazine, p. 35.)

See a most able essay on the habits, and injurious effects on vegetation, of the A'phides generally, and of the A`phis hùmuli (or hop fly, or hop louse) in particular, and in full detail, by Rusticus of Godalming, in the Entomological Magazine, vol. i. p. 217 to 224. — J. D.

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