The Zoologist/3rd series, vol 1 (1877)/Issue 10/Proceedings of Scientific Societies
PROCEEDINGS OF SCIENTIFIC SOCIETIES.
Entomological Society of London.
September 5, 1877.—Prof. J.O. Westwood, M.A., F.L.S., President, in the chair.
Donations to the Library were announced, and thanks voted to the donors.
Mr. F. Smith exhibited, on behalf of Mr. G.A. James Rothney, a fine collection of Hymenoptera, collected in the neighbourhood of Calcutta during the past season. The majority of the species belonged to the fossorial division; among them were several fine species of Sphegidæ and Bembicidæ. In the collection were several new species of the genus Cerceris, also a few new species of Apidæ, the whole series being in the finest possible condition.
Mr. M'Lachlan exhibited drawings (with details) of the extraordinary insect from Java, described by Wesmael in 1836, under the name of Himanopterus fuscinervis, as pertaining to the Lepidoptera. The insect remains to this day unique in the collection of the Brussels Museum. In 1866 Dr. Hagen transferred Himanopterus to the Neuroptera as a subgenus of Nemoptera. No palpi nor legs existed in the insect when first described, but from the neuration, general form, nature of the clothing, &c., Mr. M'Lachlan is quite certain it has nothing to do with Nemoptera, and is truly lepidopterous, allied to the North Indian insect described and figured by E. Doubleday as Thymara zoida.
Prof. Westwood stated that in 1876 he had also studied the type, and made drawings and agreed as to its position near Thymara.
Mr. M'Lachlan also exhibited leaves of a large species of Acer from trees growing in the grounds of Mons. van Volxen, at Lacken, near Brussels. These trees were many of them fifty feet in height, and almost each leaf had one or more large white blotches on it, being the mines of a small sawfly described by Kaltenbach as Phyllotoma aceris, a species occurring in England on the wild Acer campestre. The insect only first appeared in M. van Volxen's grounds last year, and was now in such extraordinary profusion that the flattened discs formed by the larvæ when full fed made quite a pattering noise as they fell from the trees. Unless the insect should disappear as rapidly as it came, there is every possibility that the combined attacks of the myriads of larvæ may seriously damage the trees.
Prof. Westwood exhibited specimens of two minute hymenopterous insects from Ceylon, closely allied to Mymar pulchellus, a British species.
Prof. Westwood also exhibited the two sexes of Narycius (Cyphonocephalus) smaragdulus, sent to him by Mr. James Wood-Mason, having been taken in the Nielgherries. One of the males exhibited was of a purple colour. The insect had remained almost unique since first described by Prof. Westwood, in 1842, in his 'Arcana Entomologica' (vol. i., p. 115).
Mr. J. Wood-Mason exhibited the two sexes of Phyllothelys Westwoodi, one of the remarkable species of Mantidæ, as to which he had observed and pointed out (in Proc. As. Soc. Beng., August, 1876, and in Ann. and Mag. Nat. Hist., 1876) that the females are distinguished by the presence either of a well -developed foliaceous frontal horn (as in Phyllocrania) or of a great vertical cephalic cone (as in Blepharis or Gongylus) from the males, wherein these processes are represented by mere rudiments; and stated that a pair of Hestias Brunneriana, another of the species in which this interesting and novel kind of distinction between the sexes had been observed, was in the collection of the British Museum, under the MS. name of Oxypilus pictipes. The latter appeared to be a species common in collections; but of the former he had hitherto seen but five specimens—three females (one a nymph) and two males—all, even the nymph, exhibiting the sexual differences referred to equally and perfectly. The specimens exhibited were, the male from Upper Tenasserim, and the female from Sibsagar, in Assam.
Mr. Mason next exhibited a beautifully executed drawing of the great stridulating spider from Assam, Mygale stridulans, in a stridulating attitude. This sketch was by Mr. S.E. Peal, who had likewise furnished Mr. Mason with a detailed description of the habits of the creature.
Mr. Mason further announced the discovery of stridulating organs in scorpions. While recently working at the anatomy of a species allied to S. afer, he had met with structures which, from his familiarity with the analogous ones in other Arthropods, crustaceans as well as insects, he had at once without hesitation determined to be sound-producing apparatus—even before he had found that sounds could be produced by them artificially by rubbing the parts together or accidentally in the mere handling of alcoholic specimens. He had, however, been enabled to place the matter beyond all doubt; for while at Bombay, waiting for the steamer, he had obtained, by a happy chance from some Hindustani conjurors, two large living scorpions belonging to another species of the same type; these, when fixed face to face on a light metal table and goaded into fury, at once commenced to beat the air with their palps and simultaneously to emit sounds, which were most distinctly audible, not only to himself, but also to the bystanders, above the clatter made by the animals in their efforts to get free, and which resembled the noise produced by continuously scraping a piece of silk fabric, or, better still, a stiff tooth-brush with ones finger-nails. The species—a gigantic one from the Upper Godaveri district—in which he had first observed stridulating organs had these organs more highly developed than in the one experimented upon at Bombay, and must stridulate far more loudly, for by artificially rubbing the parts together in a dead alcoholic specimen he could produce a sound almost as loud as, and very closely similar to, that made by briskly and continuously drawing the tip of the index-finger backwards and forwards, in a direction transverse to its coarse ridges, over the ends of the teeth of a very fine-toothed comb. The apparatus, which, as in the Mygale, is developed on each side of the body, was situated—the scraper upon the flat outer face of the basal joint of the palp-fingers; the rasp on the equally flat and produced inner face of the corresponding joint of the first pair of legs. On separating these appendages from one another, a slightly raised and well-defined large oval area of lighter coloration than the surrounding chitine was to be seen at the very base of the basal joint of each; these arege constituted respectively the scraper and the rasp; the former was tolerably thickly but regularly beset with stout, conical, sharp spinules curved like a tiger's canine, only more towards the points, some of which terminate in a long limp hair; the latter crowdedly studded with minute tubercles shaped like the tops of mushrooms. He had met with no stridulating organs in this position in any scorpions besides S. Afer and its allies; but in searching for them in other groups he had come to the conclusion that the very peculiar armature of the trenchant edges of the palp-fingers in all the Androctonoidæ, and in some at any rate of the Pandinoidæ (no Telegonoidæ nor Vejovoidæ had yet been examined), was nothing but a modification for the same purpose, for the movable finger of this pair of appendages when in the closest relation of apposition to its immovable fellow could most easily be made to grate upon it from side to side so as to produce a most distinct crepitating sound; but wiieu separated from it ever so little appeared to be incapable of the slightest lateral movement. It was his intention on his return to India to endeavour to determine this question, as well as many others relative to the species in which the presence of sound-producing apparatus had now been demonstrated by careful observation and experiment upon living animals.
Mr. Mason finally handed to Prof. Westwood for identification the larva of some homopterous insect with what appeared to be a lepidopterous casebearing larva attached to its last segment by a tough semi-transparent cord. The specimens were from Bangalore.
Mr. Wormald exhibited, on behalf of Mr. Pryer, a small collection of Chinese Lepidoptera.
Mr. G.C. Champion exhibited some rare beetles from Aviemore, Inverness-shire; among them was Pachyta sex-maculata, a Longicorn new to Britain.
Mr. J. Jenner Weir mentioned a case of parthenogenesis in Lasiocampa quercus, which bad recently come under his notice.
The President read the following letter from Herr A.W.B. Grevelink, of the Hague, relating to the insects which attack the cocoa-nut trees in the West Indies:—
"At Barbadoes the cocoa-nut trees were all destroyed by the Aleyrodes cocoïs, which afterwards, according to Sir Robert Schomburgh, extended its ravages over Antigua, Nevis, St. Christopher's, and other islands, from which I infer that it did the same in Martinique, as that island lies in the same line with the rest. The year or years, however, in which all this happened I have never been able to make out, and all that I can gather on this point, from the 'History of Barbadoes,' is that the said trees had been planted after the hurricane of 1831, and that they had attained to maturity when the insect first showed itself, which, as regards the new plantations, cannot well have been earlier than 1837.
"Now it so happened that in March of the same year, whilst serving as Lieutenant on board II. M. Brig 'Echo,' then stationed in the West Indies, I assisted in carrying over from St. Pierre, Martinique, to Curaçao a considerable number of the nopal-plant (Cactus coccinillifera), peopled, of course, by the cochineal insect; and as it was not many months afterwards that, in the last-named island, the cocoa-nut trees on some of the estates began to show symptoms of being affected as if by blight, which on examination was pronounced to be caused by an insect of the Coccidæ or Coccus genus, many persons there have ever since held the opinion that it was introduced at the same time with the cochineal from Martinique, which opinion was not a little strengthened when, in 1839, tidings from that island stated that all the cocoa-nut trees there had been destroyed by an insect (name not mentioned), but which, all things considered, I have not the least doubt was the same species which ruined the cocoa-nut trees at Barbadoes.
"After making a voyage to Europe, I arrived again at Curaçao in the beginning of September, 1838, where I took charge of the estate St, Joris, belonging to my family, on which were about two thousand cocoa-nut trees, the greater part of which were then already in a sickly condition, caused evidently by a microscopic insect which covered every part of the crown and extended also deep down into the heart of the tree, though outwardly the stem remained free from them. I applied every means that could tend to arrest their progress, in which I persevered during several months, but without any perceptible effect, for the fronds turned yellow and dropped to the ground as before. Trees which when I arrived were still healthy successively caught the infection, their leaves withered, and after they, as well as the fruit-stalks, had all dropped, down came also the centre of the crown, when nothing remained but the lifeless trunk, a useless encumbrance to the soil, as the wood is fit for nothing—not even for fuel. On all the other estates they had the same story to relate, and at the end of the year 1839 not one of those noble palm trees remained alive, which, to the number of 20,000, had graced this barren island only a year before.
"As for the appearance of the insect which caused this calamity, I can only say that, like other larvæ of Aleyrodes, it was not even so big as the head of the smallest pin in common use, and was of nearly circular outline, but quite flat, and as thin as the finest paper. It never moved that I could see, and seemed as if glued to the leaf, on which myriads of them were huddled together.
"Having thus been an eye-witness in the case, you may judge of my astonishment when, only last year, I was informed here at the Hague by a professional entomologist of some repute, that from the communication of a friend of his who visited Curaçao many years after the above-mentioned occurrence, he felt convinced that the cocoa-nut trees in that island have been destroyed by the caterpillar of a nocturnal lepidopteron. This absurd notion I have not been able to dispel, not even by producing extracts from the colonial newspaper, because, said he, although it appears therefrom that the colonists hold the same opinion as I do, yet the question remained whether that opinion is the right one. In reply, I can only say that I never expected an entomologist to believe on mere hearsay that any butterfly will soar to a height of sixty to eighty feet above the ground to lay its eggs in trees which have so little to attract them as those of the order Palmæ, whose leaves, from their texture, are unfit to serve as food for the larvae of Lepidoptera.
"Passing from this subject to that of the destruction of the cocoa-nut trees in the coast regions of Guiana, here in Holland it seems nobody ever heard of those trees suffering from insects in Surinam. I beg to refer to Mr. Russell's report on the Aleyrodes, as well as on the beetle, which, long before the arrival of the first-mentioned insect, about three or four years ago, used to spoil the said trees in those districts, and which report must have reached you long since, as it was read at one of the monthly meetings of the Royal Agricultural and Commercial Society in Demerara, and printed in the 'Royal Gazette' (George Town, British Guiana), of the 4th March, 1876.
"From that paper, I see, Mr. Russell says his friend Dr. Whitlock calls the beetle Passalus tridens, which, so far as I know, may be very correct, though, judging from the appearance of one I saw in the museum at Leyden, I should not have thought it capable of boring holes which have been compared by Mr. Russell to those made by means of an augur. Among the eight species of Passalus enumerated by Dr. Dalton, in his 'History of British Guiana,' I do not find this one; but, of course, that is no reason why it should not be found there, as the author himself does not pretend to give a complete list of insects. I was lucky enough to have the opportunity of inspecting a couple of beetles, which were caught on the estate of a respected friend of mine, the Hon. A.D. van der Yon Netscher, formerly a landed proprietor in Demerara, and member of the Council there. They were trapped by one of his coolies while in the act of burrowing in the ground for the evident purpose of finding their way through a hole in the rhizome up to the top of the tree, in order, by the attacks of their larvæ, to destroy it; the whole according to the manner described by Mr. Russell, whose very interesting account is fully corroborated by Mr. Netscher's, who has very obligingly drawn it up from his own experience, at my request. The beetles are a male and female, well known in the country as belonging to the real destroyers of cocoa-nut trees, and from their very prominent features, easily recognizable as answering in every point—the male to the description of the Scarabæus aloë, the other, or female, to that of the S. alveus in Dr. Voet's 'Catalogus Systematicus Coleopterorum,' both insects being stated to belong to Surinam. Let me add that, from their hirsute aspect, they look a by no means very amiable couple."
The Secretary exhibited a Longicorn beetle which had been sent from Birkenhead by Mr. David Henderson. It had been captured on the wing in that town, having probably flown from a ship in the river.
Mr. J.W. Slater read a paper entitled "Vivarium Notes on some common Coleoptera."—R Meldola, Hon. Sec.