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Articles 1111 - 1129 of 1129

Full-Text Articles in Entomology

Mechanisms Of Resistance In Wild Rice Oryza Brachyantha To Rice Leaffolder Cnaphalocrocis Medinalis (Guenée) (Lepidoptera: Pyralidae), R. Ramachandran, Z. R. Khan Jan 1991

Mechanisms Of Resistance In Wild Rice Oryza Brachyantha To Rice Leaffolder Cnaphalocrocis Medinalis (Guenée) (Lepidoptera: Pyralidae), R. Ramachandran, Z. R. Khan

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A wild rice, Oryza brachyantha, was rated as highly resistant to rice leaffolder, Cnaphalocrocis medinalis (Guenée), while its F1 hybrid from a cross with a high-yielding, leaffolder-susceptible rice, IR31917-45-3-2, was rated resistant in a standard screening test. In comparison with IR31917-45-3-2, O. brachyantha and the F1 hybrid were unsuitable for oviposition, survival, and growth of C. medinalis. However, growth and survival of larvae in artificial diets containing lyophilized leaf powder of IR31917-45-3-2 and O. brachyantha were comparable. Studies on the feeding and settling preference of the larval stages suggested that the mechanism of resistance of O. brachyantha is that of …

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Enhancement Of Diapause Development In A Stem Borer, Busseola Fusca (Lep.: Noctuidae) By Dry Conditions, Takashi Okuda Jan 1991

Enhancement Of Diapause Development In A Stem Borer, Busseola Fusca (Lep.: Noctuidae) By Dry Conditions, Takashi Okuda

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Water was an important factor for diapause termination only during the late stage of the diapause in Busseola fusca. Exposure to dry conditions for 2 months accelerated diapause development more. Diapause development proceeded at warm temperatures only. © 1991, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.

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Volatile Components Of Banana Pseudostem Of A Cultivar Susceptible To The Banana Weevil, Isaiah O. Ndiege, William J. Budenberg, Wilber Lwande, Ahmed Hassanali Jan 1991

Volatile Components Of Banana Pseudostem Of A Cultivar Susceptible To The Banana Weevil, Isaiah O. Ndiege, William J. Budenberg, Wilber Lwande, Ahmed Hassanali

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Volatiles from banana ('githumo''cultivar) pseudostem were trapped using porapak S. The trapped volatiles were desorbed from porapak columns by elution with dichloromethane and analysed using GC and GC-MS. The volatile compounds identified included α-pinene, β-pinene, β-myrcene, limonene, α-cubebene, α-copaene, α-cedrene, β-caryophyllene and α-humulene. © 1992.

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Trap-Catches, Nutritional Condition And The Timing Of Activity Of The Tsetse Fly Glossina Longipennis (Diptera: Glossinidae), Sarah E. Randolph, D. J. Rogers, R. D. Dransfield, R. Brightwell Jan 1991

Trap-Catches, Nutritional Condition And The Timing Of Activity Of The Tsetse Fly Glossina Longipennis (Diptera: Glossinidae), Sarah E. Randolph, D. J. Rogers, R. D. Dransfield, R. Brightwell

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Samples of Glossina longipennis Corti, taken over four days in traps (baited with acetone, cow urine and octenol) at half-hourly intervals during their restricted activity periods at dusk and dawn, were analysed for their nutritional condition. For both sexes, trap catches were highest at the end of dusk, between 19.00 and 19.30 h, associated with a significant increase in numbers with the low haematin content characteristic of flies estimated to have fed more than 60 hours previously. Also, the mean fat content of these flies was significantly lower than that of those trapped earlier. There was considerable day-to-day variation in …

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Commitment To Metamorphosis In Tsetse (Glossina Morsitans Centralis): Temporal, Nutritional And Hormonal Aspects Of The Decision, David L. Denlinger, Jan Žďárek Jan 1991

Commitment To Metamorphosis In Tsetse (Glossina Morsitans Centralis): Temporal, Nutritional And Hormonal Aspects Of The Decision, David L. Denlinger, Jan Žďárek

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Larvae of Glossina morsitans centralis were manually extruded from the uterus of the female at different times during the third (final) larval instar to evalute their competence to initiate metamorphosis. Parturition is a gated response in tsetse, and in this species the peak of activity occurred 8.7 h after the onset of the daily 12 h photophase. Larvae aborted a few hours prematurely were completely competent to crawl and pupariated within 1-2 h, but a portion of the puparia blackened before tanning. Younger larvae (22.9 mg vs full grown weight of 33.6 mg) were also competent to crawl, but after …

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Monitoring Secondary Outbreaks Of The African Armyworm In Kenya Using Pheromone Traps For Timing Of Bacillus Thuringiensis Application, M. Broza, M. Brownbridge, B. Sneh Jan 1991

Monitoring Secondary Outbreaks Of The African Armyworm In Kenya Using Pheromone Traps For Timing Of Bacillus Thuringiensis Application, M. Broza, M. Brownbridge, B. Sneh

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The arrival of male moths of the African armyworm, Spodoptera exempta Walker, was monitored in Kenya using pheromone traps. Peak trap counts were obtained during March 1989, and were concentrated in three out of nine traps distributed in small farms in an area of 625 km2 in Lambwe valley, South Nyanza. Large numbers of egg masses were located on dry stalks of last year's cereals in wild cynodon grass situated around the crop fields. Smaller numbers were found on the underside of the first emerged leaves of maize seedlings. Few egg masses were found on millet crops. Application of a …

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Lipophorin From The Tsetse Fly, Glossina Morsitans Morsitans, James O. Ochanda, Ellie O. Osir, Edward K. Nguu, Norah K. Olembo Jan 1991

Lipophorin From The Tsetse Fly, Glossina Morsitans Morsitans, James O. Ochanda, Ellie O. Osir, Edward K. Nguu, Norah K. Olembo

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1. 1. Lipophorin was isolated from the haemolymph of adult tsetse fly, Glossina morsitans morsitans, by ultracentrifugation in a potassium bromide density gradient. 2. 2. The tsetse fly lipophorin (Mr {reversed tilde equals} 600,000) has a density of {reversed tilde equals} 1.11 g/ml and consists of two apoproteins, apolipophorin-I (apoLp-I, Mr {reversed tilde equals} 250,000) and apolipophorin-II (apoLp-II, Mr {reversed tilde equals} 80,000), both of which are glycosylated as shown by staining with periodate-Schiff reagent. The protein complex is composed of 49% protein and 51% lipids. 3. 3. The finding of lipophorin in tsetse fly haemolymph suggests that, although these …

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Infection Rates In Glossina Morsitans Morsitans Fed On Waterbuck And Boran Cattle Infected With Trypanosoma Congolense, Steve Mihok, Reardon O. Olubayo, David F. Wesonga Jan 1991

Infection Rates In Glossina Morsitans Morsitans Fed On Waterbuck And Boran Cattle Infected With Trypanosoma Congolense, Steve Mihok, Reardon O. Olubayo, David F. Wesonga

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Teneral Glossina morsitans morsitans were fed on waterbuck (Kobus defassa) and Boran cattle (Bos indicus) infected experimentally with Trypanosoma congolense clone IL2895. Infection rates in tsetse varied from 9 to 31% when fed on cattle, and from 2 to 59% when fed on waterbuck. In waterbuck, infections were often detected through the development of parasites in tsetse at times when parasitaemia could not be detected through microscopic examination of blood. Male and female, and 1- and 2-day-old flies were equally susceptible to infection on both hosts. Infection in tsetse was associated with a 14% absolute reduction in survival during the …

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Pathogenicity Of Tsetse-Transmitted Trypanosoma Congolense For Waterbuck (Kobus Defassa) And Boran Cattle (Bos Indicus), R. O. Olubayo, S. Mihok, D. F. Wesonga, E. R.M. Mbwabi Jan 1991

Pathogenicity Of Tsetse-Transmitted Trypanosoma Congolense For Waterbuck (Kobus Defassa) And Boran Cattle (Bos Indicus), R. O. Olubayo, S. Mihok, D. F. Wesonga, E. R.M. Mbwabi

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Five waterbuck (Kobus defassa) and four Boran cattle (Bos indicus) were infected with Trypanosoma congolense IL2895 using Glossina morsitans morsitans. At the same time, two waterbuck and two cattle were inoculated intravenously with bloodstream forms. With both methods of challenge, cattle had short prepatent periods followed by a continuous high parasitaemia. All cattle became severely anaemic and had to be treated with trypanocidal drugs to prevent death. In contrast, tsetse and intravenous challenge of waterbuck resulted in a long prepatent period, followed by brief, intermittent levels of low parasitaemia, and eventual selfcure. Waterbuck did not become anaemic, even during short …

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Structural Studies On The Major Milk Gland Protein Of The Tsetse Fly, Glossina Morsitans Morsitans, Ellie O. Osir, Michael Kotengo, Mohammed F.B. Chaudhury, Leonard H. Otieno Jan 1991

Structural Studies On The Major Milk Gland Protein Of The Tsetse Fly, Glossina Morsitans Morsitans, Ellie O. Osir, Michael Kotengo, Mohammed F.B. Chaudhury, Leonard H. Otieno

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1. 1. The major protein in the milk gland secretions of the tsetse fly, Glossina morsitans morsitans, was isolated by a combination of gel permeation chromatography and crystallization. 2. 2. It has a native Mr ∼47,000 and is composed of two identical polypeptide chains (Mr ∼21,000) as determined by chemical cross-linking studies. The protein has no covalently-bound carbohydrates or lipids. Amino acid analysis of the protein revealed relatively high amounts of the aromatic amino acids, tyrosine (9.1 mol.%) and phenylalanine (8.5 mol.%). Immunoblotting experiments using antiserum against the protein revealed no cross-reactivity with any other milk proteins. 3. 3. Quantitation …

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Attraction Of The Stem Borer Chilo Partellus (Swinhoe) Larvae (Lepidoptera: Pyralidae) By Certain Coloured Surfaces For Trapping, Kailash Narain Saxena, Jeremiah Dickens Onyango Jan 1987

Attraction Of The Stem Borer Chilo Partellus (Swinhoe) Larvae (Lepidoptera: Pyralidae) By Certain Coloured Surfaces For Trapping, Kailash Narain Saxena, Jeremiah Dickens Onyango

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Different colour papers have been shown to attract the first and third instar larvae of Chilo partellus in different degrees. Green bice (No. 329) and light green (No. 323) elicited maximum larval attraction; followed by foliage green (No. 328) and cadmium yellow (No. 307). The green bice paper has been found to be much more effective than foliage green or cadmium yellow paper as a cylindrical sticky trap for the larvae. Even when competing with the host plant, sorghum, these colour paper traps proved more effective than the plants for attracting and trapping the larvae. © 1987, JAPANESE SOCIETY OF …

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Trail-Following In Termites: Evidence For A Multicomponent System, M. Kaib, O. Bruinsma, R. H. Leuthold Sep 1982

Trail-Following In Termites: Evidence For A Multicomponent System, M. Kaib, O. Bruinsma, R. H. Leuthold

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Several African termite species from different subfamilies and different habitats are sensitive to trail-active extracts or to naturally laid trails from other species. Using single-extract bioassays, it is shown that the response threshold for trail-following is nearly identical for all tested species (except for Hodotermes mossambicus). However, when termite workers have a choice between trails from their own species and from other species, conspecific trail-following is exclusively observed. This phenomenon can be counteracted by dilution (1:10) of the conspecific trail-pheromone extract. Tests of the trail activity of various synthetic alcohols show that among these, the highest sensitivity of termite workers …

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Influence Of The Termite Macrotermes Michaelseni (Sjöst) On Soil Fertility And Vegetation In A Semi-Arid Savannah Ecosystem, M. A. Arshad Jan 1982

Influence Of The Termite Macrotermes Michaelseni (Sjöst) On Soil Fertility And Vegetation In A Semi-Arid Savannah Ecosystem, M. A. Arshad

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The growth and species structure of vegetation in relation to the proximity of termite (M. michaelseni) mounds was studied in a semi-arid savannah ecosystem during 1978-1980. The dry matter yield in the termite-modified area at 1-10 m distance from mounds was significantly greater (P < 0.01) than that in the area beyond 22 m which is relatively unaffected by the termites. Themeda triandra and Digitaria scalarum, dominant grass species of the area, were totally absent in the 1-10 m zone around the mound. The major species in the immediate vicinity of the mound were Pennisetum stramineum and Cynodon dactylon, the latter was a dominant species (over 90%) within the 0-10 m zone and entirely absent beyond 15 m from the mound. The number of grass species increased from 2-3 species around the mound to 6-7 species in the area apparently beyond the influence of the mound. High concentration of nutrients and favourable water availability, together with good drainage, appeared to be the major causes of increased biomass and different species composition of vegetation around the mound. © 1982.

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The Influence Of Salinity On Larval Development And Population Dynamics Of Anopheles Merus Dönitz (Diptera: Culicidae), F. W. Mosha, C. M. Mutero Jan 1982

The Influence Of Salinity On Larval Development And Population Dynamics Of Anopheles Merus Dönitz (Diptera: Culicidae), F. W. Mosha, C. M. Mutero

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Variations in density of adults of Anopheles merus Dön. in Jimbo Village on the Kenya Coast were found to be correlated both with rainfall and with salinity at their breeding sites. Densities started to increase at the beginning of the rains when several breeding sites were formed. This was followed by a decline in numbers resulting mainly from the decrease in salinity in the semi-permanent breeding sites. A second rise occurred after the end of the rains, corresponding with an increase in salinity in the semi-permanent breeding sites due to evaporation. Peak density coincided with salinities of 30–50% sea water …

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Precocene-Induced Sterility In F1 Generation Of Glossina Morsitans Morsitans, M. Samaranayaka-Ramasamy, M. F.B. Chaudhury Jan 1982

Precocene-Induced Sterility In F1 Generation Of Glossina Morsitans Morsitans, M. Samaranayaka-Ramasamy, M. F.B. Chaudhury

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Precocene treatment does not disrupt the events of reproduction in Glossina morsitans morsitans or induce any apparent changes in treated tsetse. However, some females of the F1 generation are either sterile or show retardations in follicle development. Sterility is not reversed spontaneously or with juvenile hormone analogues. The critical period for precocene action is related to each ovulation. The corpora allata of precocene-treated tsetse are normal, but those of F1 sterile females are degenerate. The occurrence of retardation has enabled the characterisation of stages in follicle development in G. m. morsitans. © 1982.

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Deterrence Of Repeated Oviposition In Sorghum Shootfly Atherigona Soccata, Ashok K. Raina Sep 1981

Deterrence Of Repeated Oviposition In Sorghum Shootfly Atherigona Soccata, Ashok K. Raina

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The sorghum shootfly, Atherigona soccata, under low population density conditions lays one egg per sorghum plant. Possible regulatory mechanisms of this oviposition behavior are reported. The presence of an egg thoroughly washed and reattached to a leaf does not deter further oviposition, indicating the absence of visual cues. When washings from eggs were sprayed on sorghum plants, or when plants from which eggs had been removed were presented to a gravid female, significant deterrence was observed. Apparently a deterrent pheromone is associated with the water-soluble glue with which the females attach their eggs to the leaves. Some deterrent effect persists …

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Precocene Treatment Of The Female Tsetse Fly Glossina Morsitans Morsitans Sterilises Her Female Offspring, M. Samaranayaka-Ramasamy, M. F.B. Chaudhury Sep 1981

Precocene Treatment Of The Female Tsetse Fly Glossina Morsitans Morsitans Sterilises Her Female Offspring, M. Samaranayaka-Ramasamy, M. F.B. Chaudhury

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When adult female Glossina morsitans morsitans were treated with either precocene I or precocene II, females of the F1 generation, emerging from pupae of the 2nd, 3rd and 4th reproductive cycles failed to develop oocytes. © 1981 Birkhüuser Verlag.

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Proteins And Surface Proteins Of Leishmania Promastigotes And Their Possible Relevance To The Characterisation Of Strains, R. Ramasamy, H. Jamnadas, M. J. Mutinga Jan 1981

Proteins And Surface Proteins Of Leishmania Promastigotes And Their Possible Relevance To The Characterisation Of Strains, R. Ramasamy, H. Jamnadas, M. J. Mutinga

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Ramasamy R., Jamnadas H. & Mutinga M.J. 1981. Proteins and surface proteins of Leishmania promastigotes and their possible relevance to the characterisation of strains. International Journal for Parasitology 11: 387-390. Two strains of Leishmania isolated from phlebotomine flies and another one from a patient with kala-azar were grown in culture as promastigotes. They were analysed for protein composition and surface proteins by polyacrylamide gel electrophoresis after surface radiolabelling. Differences were observed in the characteristic patterns of proteins and surface proteins between the two strains that are likely to be Leishmania donovani and the other strain. Such differences may prove valuable …

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Ecological And Genetic Separation Of Three Sympatric Species Of Aedes (Diptera: Culicidae) From The Kenya Coast, L. P. Lounibos, L. E. Munstermann Jan 1981

Ecological And Genetic Separation Of Three Sympatric Species Of Aedes (Diptera: Culicidae) From The Kenya Coast, L. P. Lounibos, L. E. Munstermann

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Aedes ledgeri Huang, A. soleatus Edw. and A. calceatus Edw. of the group of A. aegypti (L.) of the subgenus Stegomyia collected on the coast of Kenya are distinguished on the strength of ecological and genetic (isozyme) data. The preferred oviposition sites of A. ledgeri and A. soleatus were tree holes above ground level, whereas A. calceatus favoured abandoned gastropod shells. A. ledgeri was most abundant in ecotonal habitats and A. soleatus in undisturbed forest At least two diagnostic enzyme loci separated each of the three species pairs. © 1981, Cambridge University Press. All rights reserved.

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