Illustrations of African blood-sucking flies other than mosquitoes and tsetse-flies / by Ernest Edward Austen.

  • Ernest Edward Austen
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Illustrations of African blood-sucking flies other than mosquitoes and tsetse-flies / by Ernest Edward Austen. Source: Wellcome Collection.

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    and 16). The eyes, which, as implied by the generic name, are golden green in life, are marked with conspicuous purplish spots and streaks, presenting useful specific characters,* unfortunately indistinguishable in dried specimens. The females of the genus Chrysops attack human beings as well as domestic and other animals ; they are often extremely blood¬ thirsty, and are capable of inflicting a severe bite. With reference to Chrysops dimidiata, v. d. Wulp, and Ch. silacea, Austen, as met with by him in Southern Nigeria, Mr. G. C. Dudgeon, a competent observer, writes as follows f :—“ The effects from a bite of C. dimidiatus [Chrysops dimidiata, v. d. Wulp] were similar to a honey¬ bee’s sting, causing a good deal of pain and inflammation, but from that of the red Chrysops [Ch. silacea, Austen] even more severe, with dropsical-like swelling of the limb and high temperature. My carriers appeared very much afraid of this insect, and hastily dropped their loads when one came near in order to arm themselves with branches to ward off its attack ; this they never troubled to do for other biting flies. Both species mentioned are somewhat similar to Syrphidce (Hover-flies) in appearance, and, as they also hover round the person they intend to attack, their flight is not unlike that of these flies.” From the observations of Hart and Hine upon Life-history. North American species it would appear that the eggs are usually deposited upright in a single layer, “ forming an oval or diamond-shaped area,” upon the leaves and stems of plants overhanging pools and small lakes. The eggs, which are white when first laid, gradually turn brown or black. The larvce live in water, mud, or the matted and sodden remains of aquatic vegetation. Both larva and pupa are of the usual Tabanid type. The larva may be distinguished from that of Tabanus by the last joint of the antenna being considerably longer than the preceding one, instead of the same length or much shorter. * Gf. V. A. E. Daecke’s interesting paper, “ On the Eye-Coloration of the Genus Chrysops ” : Entomological News, Yol. XVII., pp. 39-42, PI I. (1906). t Gf. G. C. Dudgeon, Journal of {Tropical Medicine, Vol, IX., p. 327, November 1, 1906).