. Transactions of the Entomological Society of London. Fig. 6. Head of Loxaspis villosus Stal (1865).,, 7. ,, ,, Polyctenes molossu-i Gigl. (1864). totally blind. The Cimicidae are usually found where batssleep, only visiting their hosts in order to take nourishment,as they are temporary parasites. The Polyctenidae, on theother hand, live in the fur of bats, not leaving the are more intensely parasitic and exist in almost uni-formly dark surroundings. Is it the intensity of parasitismor the darkness which has caused the loss of eyes in Poly- ( cxlvii ) ctenidael A comparison with oth
. Transactions of the Entomological Society of London. Fig. 6. Head of Loxaspis villosus Stal (1865).,, 7. ,, ,, Polyctenes molossu-i Gigl. (1864). totally blind. The Cimicidae are usually found where batssleep, only visiting their hosts in order to take nourishment,as they are temporary parasites. The Polyctenidae, on theother hand, live in the fur of bats, not leaving the are more intensely parasitic and exist in almost uni-formly dark surroundings. Is it the intensity of parasitismor the darkness which has caused the loss of eyes in Poly- ( cxlvii ) ctenidael A comparison with other groups of ectoparasiteswill enable us to answer the question. Among the Siphon-aptera the very intensely parasitic Echidnophaga and Derma-tophilus penetrans have not lost the eye; they fasten them-selves on the naked or comparatively bare parts of the skin ofthe host, in birds, for instance, around the eyes and ears, andon the wattles of fowls, in mammals on the ears and ? of Dermatophilus penetrans burrows into the bare skin,. Fig. 8. Head of Xenopsylla eridos Roths. (1904).9. ff ,, ,, niloticus Roths. (1908). 10. ., „ niloticus Roths. (1908). 11 , ,, brasiliensis Baker (1905) \\ 12. ,, „ „ tortus Roths. (1908). 13. „ „ Booseveldtiella georychi Fox (1913). but even that habit is not accompanied by the loss of theeyes. The nearest allied species, D. caecata, however, has areduced eye : and this species swells up in such a curiousway in the $, that the abdomen almost completely envelopesthe head and thorax. In both species the $ <J do not burrowinto the skin. Again, among the Anoplura, the human liceare at least as intensely parasitic as the Polyctenids, but theyhave nevertheless preserved the eyes, while other species oflice, living in the fur of burrowing mammals, have the eyesmuch reduced or absent. All this appears to show that the ( cxlviii ) degree of parasitism is of less importance in connection withthe reduction of the eye than the absence of li
Size: 1920px × 1301px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorr, bookcentury1800, booksubjectentomology, bookyear1836
