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Genus Lithoaphis Takahashi, 1959 is reported from China. One new species Lithoaphis quercisucta sp. nov. from Yunnan Province, China is described. Diagnosis character, key of species, distribution, host plant and biology of the genus Lithoaphis are provided. Morphological description, feature pictures, distribution, and host plant of the new species are included in this paper. All specimens including the type are deposited in the Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, P. R. China.
The aphid subgenus, Tuberolachnus (Tuberolachniella) Hille Ris Lambers et Basu, 1966 is newly recorded from China. A new species, Tuberolachnus (Tuberolachniella) macrotuberculatus sp. nov. is described. The types are deposited in Zoological Museum, Institute of Zoology, Chinese Academy of Sciences.
Surface waxes from wax-covered triticale plants (RAH 122) were sprayed on plants of the waxless genotype RAH 366 or the surface waxes were used to make artificial diet preparations. The results were significant increases in the mortality of apterous adults of the grain aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae) at all concentrations tested in comparison with those aphids which fed on the control plants or aphids which were reared on the diets. In the choice tests, most aphids settled on plants without surface waxes or on diet preparations which did not have surface waxes (the controls). When the concentration of the surface waxes was increased on one of the plants or surface waxes were increased in the diet preparation, the number of wandering aphids increased. Those aphids which did not wander were mainly on the waxless control plants or on the waxless diet preparations. Aphids did settle on those plants or on the diet preparations which had 100 and 1,000 μg · g–1 of surface wax. The aphids rarely settled on the diet preparations containing 10,000 μg ∙ g–1 of surface waxes. From these observations it appears that surface waxes can act as a feeding deterrent. Since aphids on plants with surface waxes, or aphids which settled on diet preparations with surface waxes, started to die earlier than aphids fed only the control plants or the control diet preparations, it is possible that the surface waxes had a toxic effect that led to early mortality. Thus, it can be said that the surface waxes caused feeding deterrence and had a toxic effect on the aphids.
The cotton aphid, Aphis gossypii is an economically significant insect pest infesting various important crops and vegetables. The neonicotinoid, acetamiprid was recommended against aphids with excellent results. Resistance emergence and environmental pollution makes acetamiprid a favorable alternative to conventional insecticides. The aims of the present work were to predict acetamiprid resistance risk in A. gossypii, investigate cross resistance to other tested insecticides and explore acetamiprid stability in the absence of selection. A field-collected population from Sharqia governorate, Egypt was selected with acetamiprid. After 16 generations of selection, there was a 22.55-fold increase in LC50 and the realized heritability (h2) of resistance was 0.17. Projected rates of resistance indicated that, ifh2 = 0.17 and 50% of the population was killed at each generation, then a tenfold increase in LC50 would be expected in 12.2 generations. If h2 was 0.27 then 7.63 generations would be needed to achieve the same level. In contrast, with h2 of 0.07 it necessitates about 30 generations of selection to reach the same level. Cross resistance studies exhibited that the selected strain showed obvious cross resistance to the other tested neonicotinoid members, moderate cross resistance to alpha-cypermethrin and no cross resistance to pymetrozine. Fortunately, resistance to acetamiprid in the cotton aphid was unstable and resistance reverses the nearby susceptible strain throughout five generations without exposure to acetamiprid. Our results exhibited cotton aphid potential to develop resistance to acetamiprid under continuous selection pressure. The instability of acetamiprid makes A. gossypii amenable to resistance management tactics such as rotation with pymetrozine.
First descriptions of fundatrix morphs of Pterocomma tremulae Börner, 1940 and P. pilosum Buckton, 1879 are presented with some taxonomical comments on their morphological traits. The key to the known fundatrices of European representatives of the genus Pterocomma is provided.
As a result of two-years studies carried out in the Dendrological Garden in Poznań 47 aphid species representing 2 families: Adelgidae and Aphididae wwere found. Aphids were collected on 26 tree species and 38 shrubs species.
Celem badań było określenie wpływu wyciągów z roślin z rodziny rdestowatych (Polygonaceae) na mszycę burakową (Aphis fabae Scop.) i jej parazytoidy (Hymenoptera: Parasitica). Napary z rdestów: wężownika, powojowego i plamistego powodowały stopniowy spadek liczebności mszyc na jaśminie wonnym, chociaż skuteczność tych wyciągów jako aficydów była w warunkach laboratoryjch niska. Opryskiwanie kolonii mszyc w laboratorium powodowało obniżanie liczebności i liczby wylęgających się z nich parazytoidów pierwotnych.
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