A NOTE ON THE GENUSULTRACOELOSTOMACOCKERELL (HOMOPTERA : MARGARODIDAE)

Life history of the sooty beech scale (Ultracoelostoma assimile) (Maskell), (Hemiptera: Margarodidae) in New ZealandNothofagusforests

“…In the field he noted 1 large emergence of males at the same time that most of the females are in their 2nd instar and concluded that mating must take place at this time because eggs were found several weeks later. Although Dumbleton (1967) reported an accurate estimate of 4 female instars he suggested that in the apparent absence of males, U. assimile was probably parthenogenetic. Our studies confirmed the presence of males, but the breeding system in U. ussimile remains a mystery.…”

“…Further study of the breeding system in New Zealand Margarodidae will provide an interesting comparison with that of Z q a sp. Dumbleton (1967) commented that mating was unlikely to occur in the 2nd instar female. He suggested that it would be diEicult because the anal filament aperture of the female test is occluded with the cast skins of previous stages and that it would be almost impossible for the male prepupa to emerge from tests similar to those of the female since these are hard and have a small aperture.…”

“…Moreover, in recent years beekeepers have become aware of the potential of honeydew as a source for the commercial production of "bush honey". Previous studies of the sooty beech scale have been limited to taxonomic work (Brittin 1935(Brittin , 1936Cockerel1 1902;Dumbleton 1967;Maskell 1889Maskell , 1891Morrison & Morrison 1922;Morrison 1928;Oliver 1975) and investigations of honeydew production for the honeydew industry (Anon 1986;Belton 1976Belton , 1978Belton &Crozier 1979;Cook 1971a, 197 lb, 1978a andb;Crozier 1978Crozier , 1981Reid 1978;Smellie 1949;Smith 1980). Except for Belton (1978) and Moller et al (1987), little attention has been paid to the ecology of the insect, to phenology, fecundity and the role of males.…”

Description of the male of the endemic New Caledonian speciesAenetus cohici(Lepidoptera: Hepialidae)

“…comm.). The sole New Zealand species, A. virescens (Doubleday), has only a subbasal spine and a shallow median spine (Philpott 1927, Dumbleton 1966 (Fig. 3).…”

Contribución al conocimiento de los primeros geotécnicos del siglo XX

“…Mecánica de Suelos e Ingeniería de Cimentaciones, Terzaghi comparó los arcos circulares con espirales logarítmicas y con las cicloides, llegando a afirmar que el uso de arcos circulares era más conveniente para el cálculo y que ofrecían una precisión suficiente para los problemas ingenieriles (Terzaghi, 1936a). En Mayo de 1939 fue cuando Terzaghi en una conferencia impartida en el ICE 445 , refiriéndose al trabajo de Petterson y Hultin 446 , habló del Método del Círculo Sueco, es decir, del método de superficies circulares de deslizamiento, basado en el hecho empírico de que las secciones transversales de una superficie de deslizamiento se aproximaba a la forma de un arco circular.…”