Annual report on the Medical Research Institute / 1909-.

  • Nigeria. Medical Research Institute.
Date:
[1923]
Catalogue details

Licence: Public Domain Mark

Credit: Annual report on the Medical Research Institute / 1909-. Source: Wellcome Collection.

    25/34 page 23
    C. fatigans, five, one with filaria, four negative. C. thalassius, five, one with? oocysts on stomach wall, four negative. Ochlerotatus irritans, five, all negative. Stegomyia (Aedes) fasciata (argenteus) four, all negative. Culex tigripes, two, negative. C. quasigelidus, two, negative. 0. grahami. one, negative. C. duttoni, one, „ Anopheles umbrosus, one, negative. Taefniorrhynchus annetti, one, negative. The differences between the stomachs of the various mosquitoes and also between their glands, are remarkable. The stomach of Man- sonioides africana is very tough, as are also the glands which usually hav.e # bifurcations at the tips. The glands and the stomach of Culiciomyia nebulosa are extremely soft and very easily burst. A record was kept for six months, of the number of rafts of mosquito eggs laid in a barrel which received the waste water from a wash-hand basin. The rafts were counted each morning, after which they were removed singly, and the barrel emptied. No note was made of single eggs laid. The figures are :— January ... ... 339 February ... 302 March ... 18(5 April ... 095 May ... 354 J une ... 1,134 Th® mont„h of March may be regarded as the end of the dry nebulosa M°St °f the rafts weie iaid Oulex decens and by Culiciomyia MOSQUITO LARVAL . ‘^s *n past, collections of mosquito-larvae made by the Sanitary Inspectors on their daily rounds in the Municipal area of Lagos were kindly sent by the Medical Officer of Health, Dr. R. W. Orpen to uvli1 VT „f.°r Jden*I®<'atlon- 868 collections were received and in .,,.e ' 1 d b® )oud tll(; receptacle and the larvae as identified. It wili be seen that, as formerly, the larvae of Aedes (Stegomyia) argenteus (fasciata) greatly outnumber the others, the total collections being 634 and the favourite breeding place being the house-hold water pots and other receptacles containing, in most cases clear water. Culici- omyia nebulosa is next in order of frequency, occurring as it did in 216 receptacles. I he favourite breeding medium for this mosquito is a ,?ontfmaZ mch decomposing and malodorous matter such as g o and native dyes. The other mosquitoes hatching out from the Ode* ,W W61? . ('‘rf, fati§ans eighteen. Anopheles costalis twelve, r i ?• eiSht. OchIerotatus irritans seven, Stegomyia luteofephala two, t ulex tigripes two, and Oulex insignis one.
    digitised image 1
    digitised image 2
    digitised image 3