No. XVII.-ORTHOPTERA, PHASMIDAE OF THE SEYCHELLES.

Abstract

Read 21st March 1912. THE PhasmidE brought from the Seychelles by the Percy Sladen Trust Expedition are remarkable firstly by the character of their local distribution within those islands. Out of the 6 species found there, 5 are peculiar to the Seychelles, and only 1 single species (Phyllium bioculatum Gray) is widely distributed. Now Mr Scott informs me that all the specimens of the 5 peculiar species (i.e. the Curuusius and G7wfea) collected by him, and among which are 3 new species, were found in the mountain-forests, most of them in the highest parts, among the endemic forest vegetation: on the other hand no Phyllium was found by him in the forests, but all those in the collection were given by residents or local collectors, who stated that these insects are found in the foliage of guava-bushes (Psidium), and perhaps of some other non-endemic plants in the lower cultivated country. If we consider now the wider geographical distribution we see that all the species of Phyllium recorded from the Seychelles are found, outside that country and Mauritius, only in India, Ceylon, and the East Indies ; and that, likewise, the genus Camusius has its centre of distribution in the Malay Archipelago, and extends also into India, Ceylon, the South of China, and Australia ; while the genus Grmfeu has been hitherto recorded only from Australia, Celebes, New Guinea, Fiji, Society Islands and other localities in those regions t * The two authors' portions of the work are distinguished by their names being placed in brackets a t the end of each of their several sections. A small but interesting series of Phasmidae was collected by the "Sealark" Expedition in 1905. This material was worked out by Dr Bolivar, and sent back by him to Cambridge : he found among it a new species (Carausius gurdineri), the description of which is included in this paper, and also two others (first obtained by Alluaud in 1892) which he had previously described in Ann. SOC. Ent. Prance, xiv. 1895, pp. 369-385. A much larger material was collected in 1908-9, and this was studied by M. Ferrihre a t the Cambridge University Museum in the autumn of 1911. He not only had before him the material determined by Dr Bolivar and the latter's manuscript, but he also visited the Hope Department of the Oxford Museum in order to consult the fine collection of Phasmidae preserved there. I n the Seychelles collection of 1908-9, he referred a large number of specimens to the species already determined by Dr Bolivar, but he also described the two new species Carazksius scotti and GrEffea sayc?helknsis. M. Ferribre has incorporated his own and Dr Bolivar's manuscripts into the present paper and written the introduction thereto. I have myself added certain particulars as to localities, habits, &c., and have also, with Dr Bolivar's permission, translated those parts of his manuscript which were written in French.-HUGH SCOTT. t The Indo-Australian affinities of the Seychelles Phasmidae are commented on by Professor Kolbe in the introduction to his paper on "Die Coleopterenfa...

Intrasexual Aggression in the Stick InsectsDiapheromera Veliei and D. Covilleae andSexual Dimorphism in the Phasmatodea

“…In the only account known to me of attempted mate theft by a stick insect, an intruding male Orxines macklotti made several futile efforts to engage his genitalia, climbed off and walked away (Robinson 1965). Also indicative of a passive defense was a congregation of Carausius alluaudi collected in the Seychelles Islands consisting of 6 males clasping a female's abdomen at various points (a seventh male was nearby) (Bolivar and Ferriero 1912).…”