Observations on the biology and taxonomy of the eggs of Anopheles mosquitos
- 1 June 1968
- journal article
- research article
- Published by Cambridge University Press (CUP) in Bulletin of Entomological Research
- Vol. 57 (4), 495-508
- https://doi.org/10.1017/s0007485300052858
Abstract
A study of the egg shells of 11 species of Anopheles was made with the stereoscan electron microscope. A number of structures have been found that are useful in distinguishing between eggs of different species; all of them can also be seen with the light microscope. A list is given of these structures, together with others already known to be of taxonomic importance.The functional significance of the network of the outer layer of the chorion of Anopheles eggs is discussed. It is suggested that the film of gas held by the network is of selective advantage in that it contributes to the buoyancy of the egg, provides it with a part of its protective coloration, and functions as a plastron when the egg is submerged. The plastron of A. labranchiae atroparvus Van Thiel resisted wetting at an excess pressure of more than half an atmosphere.The relation of Anopheles eggs to the surface film is discussed. A highly stable line of contact with the water is formed, such that the water surface is depressed along the sides of the egg and raised at each end. Because like menisci are attracted and unlike ones repelled, eggs make contact with each other end to end or side to side, never end to side. Water spreads on most natural objects, forming menisci like those at the ends of the egg, which is thus provided with anautomatic trapping device that tends to attach the egg endwise to an object projecting from the water. The selective advantage of endwise over sideways attachment is not known, but it may facilitate hatching.The structure of the egg of A. pseudopunctipennis Theobald has been disputed, and it is therefore described in some detail.Keywords
This publication has 13 references indexed in Scilit:
- Structure and protective devices of the egg of the mosquito Culex pipiensJournal of Insect Physiology, 1968
- The respiratory system of the egg-shell of the blowfly, Calliphora erythrocephala Meig., as seen with the electron microscopeJournal of Insect Physiology, 1963
- The structure and function of the respiratory horns of the eggs of some fliesPhilosophical Transactions of the Royal Society of London. B, Biological Sciences, 1960
- Plastron Respiration in the Eggs of Drosophila and other fliesNature, 1959
- Notes on the Eggs of Some East AfricanAnophelesPathogens and Global Health, 1955
- Viability of Anopheles Gambiae Eggs and Morphology of Unusual Types Found in BrazilThe American Journal of Tropical Medicine, 1943
- Further Notes on the Overwintering of the Eggs of Anopheles walkeri Theobald with a Description of the EggsJournal of Parasitology, 1938
- The Egg of Anopheles pseudopunctipennis in PanamaJournal of Parasitology, 1937
- A Comparative Study of the Eggs of Californian AnophelinesJournal of Parasitology, 1932
- The Egg Laying Habits of Californian AnophelinesJournal of Parasitology, 1920