OCR Text |
Show 640 MR. A. D. MICHAEL ON THE [Dec. 1, The numbers of Aphidse, Coleoptera, and indeed of other insects which are commonly found in Ants' nests are too well known to require any reference by me ; but the observations on the presence of Acariin a similar situation are, as far as I know, very few. Forel in his great work 'Les Fourmis de la Suisse,' published in 1874, speaking of Myrmecophilous insects (p.424), says:-" Acarina appear to enjoy a certain immunity; they run about amongst the ants without exciting their anger ; it is rare to see them attach themselves to the bodies of their hosts or to those of the larvae or nymphs. 1 have nevertheless observed the fact many times, and as it is the mode of life of most Acari we may probably consider it as general in this instance also. Moreover, living in the nest the Acari do not risk anything in releasing one ant, because they can find as many others as they wish." This is, I believe, his only notice of the subject. It will be seen that Forel does not say what Acari he is talking about, and they are almost as various as the different groups of the Insecta ; he also falls into the very general, but by no means correct, view of supposing that the great bulk of the Acarina are parasitic, whereas in fact probably not half the species are ever parasitic, and amongst those that sometimes are so by far the larger proportion are only parasitic in an immature stage, not when adult; and among these a very large number only use their host as a means of conveyance, and are not parasitic in any other sense. The first notice, which I am aware of, specially connecting any Gamasids with Ants is that of Haller in 18771, who describes a species which he makes the type of a new genus and which he received from Dr. Uhlmann, who found it, apparently near Munich, parasitic upon (auf) Formica nigra. Haller does not state, and probably did not know, the extent of the parasitism ; he had a dozen specimens. At the end of his description Haller says " Parasitic upon Insects, especially Ants ;" he does not, however, give any reason why he believes it to be parasitic on anything except Formica nigra. This remained the only species of the genus until 1888, when Prof. Berlese described two new species found by A. Balzan 2„ One from Brazil, called " caput-carabi," in spite of its name, is not stated to have been found on any insect; but is so called because the whole mite is supposed to resemble the head of a Carabus ; the other, viduus, was found upon a Beetle of the genus Scarites. The next notice is that of Sir John Lubbock, who in 1881 found a very curious Uropoda in the nests of Lasius favus ; he obtained several specimens, and informed me that it was not uncommon in the nest of that species of Ant. It was called Uropoda formicarice3. The only other record which I know of refers to one of the species dealt with in this paper, which was unknown when I started 1 " Antenophorus uhlmanni, ein neuer Gamaside," Archiv fur Natursresch. Hft. xliii. p. 57, 2 " Acari Austro-Americani quos collegit Aloysius Balzan," Bull. Soc. Ent. Ital. 1888. 3 " Observations on Ants, Bees, and Wasps.-Part VIII.," Journ. Linn. Soc, Zool. vol. xv. (1881) p. 386. |