. The Cambridge natural history. Zoology. 6o HYMENOPTERA. Fig. 23.—Psilhyrus restalis. Britain. A, Female, B, outer side of hind leg. no harm beyond appropriating a portion of their food supphes. Sehmiedeknecht says they are commensals, not parasites; but it must be admitted that singularly few descriptions of the habits and life-histories of these interesting Insects have been recorded. Hoffer has, however, made a few direct olDservations which confirm, and at the same time make more definite, the vague ideas that have been generally prevalent among entomologists. He found and took home a nes
. The Cambridge natural history. Zoology. 6o HYMENOPTERA. Fig. 23.—Psilhyrus restalis. Britain. A, Female, B, outer side of hind leg. no harm beyond appropriating a portion of their food supphes. Sehmiedeknecht says they are commensals, not parasites; but it must be admitted that singularly few descriptions of the habits and life-histories of these interesting Insects have been recorded. Hoffer has, however, made a few direct olDservations which confirm, and at the same time make more definite, the vague ideas that have been generally prevalent among entomologists. He found and took home a nest of Bom- Inis variabilis, which contained also a female of Psithyrus campestris, so that he was able to make observations on the two. The Fsithyrus was much less industrious than the Bombus, and only left the nest somewhat before noon, returning home again towards evening; after about a month this specimen became still more inactive, and passed entire days in the nest, occupying itself in consuming the stores of honey of its hosts, of which very large ([uantities were absorbed, the Psithyrus being much larger than the host-bee. The cells in which the young of the Psithyrus are hatched are very much larger than those of the Bomius, and, it may therefore be presumed, are formed by the Psithyrus itself, for it can scarcely be supposed that the Bombus carries its complaisance so far as to construct a cell specially adapted to the superior stature of its uninvited boarder. When a Psithyrus has been for some time a regular inhabitant of a nest, the Bombus take its return home from time to time as a matter of course, displaying no emotion what- ever at its entry. Occasionally Hoffer tried the introduction of a Psithyrtis to a nest that had not previously had one as an in- mate. The new arrival caused a great hubbub among the Bombus, which rushed to it as if to attack it, but did not do so, and the alarm soon subsided, the Psithyrus taking up the position in the nest usually affecte
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
