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Articles 2341 - 2370 of 2421

Full-Text Articles in Life Sciences

Studies On The Maturation-Accelerating Pheromone Of The Desert Locust Schistocerca Gregaria (Orthoptera: Acrididae), Hassane Mahamat, Ahmed Hassanali, Hezekiel Odongo, Baldwyn Torto, El Sayeed El-Bashir Sep 1993

Studies On The Maturation-Accelerating Pheromone Of The Desert Locust Schistocerca Gregaria (Orthoptera: Acrididae), Hassane Mahamat, Ahmed Hassanali, Hezekiel Odongo, Baldwyn Torto, El Sayeed El-Bashir

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The accelerating effect of mature males of the desert locust, Schistocerca gregaria, on the maturation of immature male and female conspecifics was confirmed. The onset of sexual activity was found to correlate with yellowing of the male insects. Using the colour as an indicator of maturation, the maturation-hastening effect of an hexane extract from mature males was also confirmed. Likewise, volatiles from mature males placed in the upper storey of a two-chamber bioassay system (no visual or tactile contact possible) and charcoal-trapped volatiles from the mature males also induced accelerated maturation in recipient males placed in the lower storey. GC …

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Semiochemicals From Anal Exudate Of Larvae Of Tsetse Flies Glossina Morsitans Morsitans Westwood And G. Morsitans Centralis Machado Attract Gravid Females, David E. Leonard, R. K. Saini Sep 1993

Semiochemicals From Anal Exudate Of Larvae Of Tsetse Flies Glossina Morsitans Morsitans Westwood And G. Morsitans Centralis Machado Attract Gravid Females, David E. Leonard, R. K. Saini

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Tsetse flies (Diptera: Glossinidae:Glossina) mature their offspring in utero, giving birth to mature larvae that burrow into soil and pupariate. During the hot dry seasons, puparia of some species of tsetse are aggregated in areas of deep shade in dense thickets. We have confirmed the presence of a semiochemical from the prepupariation excretions of larvae of Glossina morsitans morsitans Westwood and report a similar semiochemical in Glossina morsitans centralis Machado. These semiochemicals are attractive to gravid females and result in the aggregation of puparia. Behavioral studies with G. m. centralis showed that a higher percentage of females larviposited over moist …

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Evidence For Volatile Male-Produced Pheromone In Banana Weevil Cosmopolites Sordidus, William J. Budenberg, Isaiah O. Ndiege, Florence W. Karago Sep 1993

Evidence For Volatile Male-Produced Pheromone In Banana Weevil Cosmopolites Sordidus, William J. Budenberg, Isaiah O. Ndiege, Florence W. Karago

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Females of the banana weevil, Cosmopolites sordidus, were attracted to and made longer visits to live conspecific males, trapped volatiles from males, and dissected male hindguts in a still-air olfactometer. Male weevils were attracted to volatiles trapped from males and made longer visits to live males and volatiles from males. Live females, collected volatiles from females and female hindguts, elicited small or no behavioral responses from either sex. Electroantennogram (EAG) responses from both male and female antennae were elicited by collected volatiles from males and by dichloromethane extracts of male hindguts and bodies but not by surface washes of males. …

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Evidence For Mediation Of Two Releaser Pheromones In The Aggregation Behavior Of The Gregarious Desert Locust, Schistocerca Gregaria (Forskal) (Orthoptera: Acrididae), Daniel Obeng-Ofori, Baldwyn Torto, Ahmed Hassanali Aug 1993

Evidence For Mediation Of Two Releaser Pheromones In The Aggregation Behavior Of The Gregarious Desert Locust, Schistocerca Gregaria (Forskal) (Orthoptera: Acrididae), Daniel Obeng-Ofori, Baldwyn Torto, Ahmed Hassanali

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The response of nymphal and adult gregarious phase desert locust, Schistocerca gregaria, to a choice of two columns of air, one permeated with airborne volatiles emanating from nymphs or adults and the other untreated, was investigated in a single-chamber bioassay arena. The nymphs, whether released individually or in groups, preferred to be within the precinct of the air column treated with airborne volatiles of the nymphs but were indifferent to volatiles of the adults. Conversely, older adults responded only to their own volatiles but not to those of the nymphs or young adults. The young adults were responsive only to …

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Inhibition Of Glossina Morsitans Midgut Trypsin Activity By D-Glucosamine, E. O. Osir, M. O. Imbuga, P. Onyango Feb 1993

Inhibition Of Glossina Morsitans Midgut Trypsin Activity By D-Glucosamine, E. O. Osir, M. O. Imbuga, P. Onyango

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The effect of the amino sugar d-glucosamine on trypsin in crude midgut homogenates of Glossina morsitans morsitans was studied in vitro. The results showed that the midgut trypsin was specifically and competitively inhibited by d-Glucosamine. Glucose, fructose, mannose, inositol, galactose, galactosamine, N-acetyl-d-glucosamine, and methyl-α-d-glucosamine were ineffective as inhibitors, even at concentrations exceeding 600 mm. d-glucosamine also had a similar inhibitory effect on bovine pancreatic trypsin. In both cases, the inhibition was incomplete as shown by nonlinear Dixon plots. The Michaelis and inhibition constants estimated for the midgut trypsin were 41±2 μm and 68±3 mm, respectively. These results suggest that the …

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Mutangin, A Dihydroagarofuranoid Sesquiterpene Insect Antifeedant From Elaeodendron Buchananii, Muniru K. Tsanuo, Ahmed Hassanali, Isaac J.O. Jondiko, Baldwyn Torto Jan 1993

Mutangin, A Dihydroagarofuranoid Sesquiterpene Insect Antifeedant From Elaeodendron Buchananii, Muniru K. Tsanuo, Ahmed Hassanali, Isaac J.O. Jondiko, Baldwyn Torto

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A novel sesquiterpene (mutangin) of the eudesmane type with five hydroxyl functions has been isolated from unripe fruits of Elaeodendron buchananii. © 1993.

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Editorial Overview, Stephen J. O'Brien, Michael T. Clegg Jan 1993

Editorial Overview, Stephen J. O'Brien, Michael T. Clegg

Biology Faculty Articles

No abstract provided.

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Experimental Immunity Against Trypanosomiasis In Rabbits, Curtis Powell Jan 1993

Experimental Immunity Against Trypanosomiasis In Rabbits, Curtis Powell

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Rabbits were immunized with specially prepared subcellular fractions of a cloned Trypanosoma brucei brucei stock 427. One fraction was found to be highly immunoprophylactic in rabbits exposed to the vector fly genus Glossina m. morsitans (tsetse flies) infected with EATRO Trypanosoma brucei brucei 1969. The most immunoprotective fraction IPFA from T. b. brucei 427 gave 75% protection to animals challenged by EATRO T. b. brucei 1969. IPFA also showed the highest IgG antibody titre against the heterologous and homologous strains. In in vitro studies, the sera from these immunized rabbits killed different strains of parasites, T. b. brucei strains 1969 …

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Effectiveness Of The Entomopathogenic Fungus Beauveria Bassiana (Bals.) Vuill. For Control Of The Stem Borer Chilo Partellus (Swinhoe) In Maize In Kenya, Nguya K. Maniania Jan 1993

Effectiveness Of The Entomopathogenic Fungus Beauveria Bassiana (Bals.) Vuill. For Control Of The Stem Borer Chilo Partellus (Swinhoe) In Maize In Kenya, Nguya K. Maniania

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The fungus Beauveria bassiana (Bals.) Vuill. and insecticide trichlorfon were compared for the control of stem borer, Chilo partellus (Swinhoe) in field experiments at different times of infestation. Egg masses of C. partellus at the blackhead stage were pinned to the undersurface of the maize leaves. Two fungal formulations, conidial aqueous suspensions and a granular formulation, were applied. Compared with the untreated checks, the numbers of surviving C. partellus larvae were significantly reduced in treatments where B. bassiana was applied at a concentration of 1013 conidia ha-1 as granules and as two aqueous spray formulations. No significant difference in numbers …

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Temporal Synthesis Of Cuticle Proteins During Larval Development In Glossina Morsitans, Vincent O. Ochieng, Ellie O. Osir, James O. Ochanda, Norah K. Olembo Jan 1993

Temporal Synthesis Of Cuticle Proteins During Larval Development In Glossina Morsitans, Vincent O. Ochieng, Ellie O. Osir, James O. Ochanda, Norah K. Olembo

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1. 1. Larval development in Glossina species occurs in utero with the mature third instar larva being deposited after a developmental period of 7 days. 2. 2. In this study, the patterns of cuticular protein synthesis during larval development were analysed by two-dimensional gel electrophoresis. 3. 3. From the results, four types of cuticle proteins were identified: those specific to larval, pupal and adult cuticles, and others common to all the stages. 4. 4. Few cuticular proteins were synthesized between the first and second larval instars. By the third larval instar (two days before larviposition), a large number of proteins …

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Striga Hermonthica Resistance In Upland Rice, Z. Harahap, K. Ampong-Nyarko, J. C. Olela Jan 1993

Striga Hermonthica Resistance In Upland Rice, Z. Harahap, K. Ampong-Nyarko, J. C. Olela

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Upland rice breeding lines were evaluated in field trials for resistance to the obligate hemi-root parasite Striga hermonthica at two sites in Kenya in 1990 and 1991. The lines differed in their reaction to S. hermonthica ranging from highly resistant to extremely susceptible. IR 49255-B-B-5-2, IR 38547-B-B-B-7-2-2, IR 47255-B-B-5-4 and Ble Chai were confirmed resistant to S. hermonthica. The indication is that the gene for resistance to S. hermonthica is widespread in rice. © 1993.

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Metamorphosis Behaviour And Regulation In Tsetse Flies (Glossina Spp.) (Diptera: Glossinidae): A Review, J. Žďárek, D. L. Denlinger Jan 1993

Metamorphosis Behaviour And Regulation In Tsetse Flies (Glossina Spp.) (Diptera: Glossinidae): A Review, J. Žďárek, D. L. Denlinger

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This review examines the recent literature on tsetse (Glossina spp.) metamorphosis behaviour and its regulation. The behavioural events associated with metamorphosis are highly specific and most occur only once during the life of the fly. The review begins with the larva's commitment to metamorphosis and then discusses the behaviour associated with parturition, wandering of the third instar larva, pupariation, pupation and adult eclosion. While certain aspects of tsetse metamorphosis behaviour are common to the higher Diptera, the peculiar reproductive strategy of tsetse has dictated many modifications. Most notable of the tsetse peculiarities are the larva's late commitment to metamorphosis, the …

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The Influence Of Host Blood On Infection Rates In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense, T. Brucei And T. Simiae, S. Mihok, R. O. Olubayo, N. Darji, E. Zweygarth Jan 1993

The Influence Of Host Blood On Infection Rates In Glossina Morsitans Sspp. Infected With Trypanosoma Congolense, T. Brucei And T. Simiae, S. Mihok, R. O. Olubayo, N. Darji, E. Zweygarth

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Trypanosoma congolense, T. brucei and T. simiae isolated from wild-caught Glossina pallidipes were fed to laboratory-reared G. morsitans centralis and G. m. morsitans to determine the effect of host blood at the time of the infective feed on infection rates. Bloodstream forms of trypanosomes were membrane-fed to flies either neat, or mixed with blood from cows, goats, pigs, buffalo, eland, waterbuck and oryx. The use of different bloods for the infective feed resulted in differences in infection rates that were repeatable for both tsetse subspecies and most parasite stocks. Goat, and to a lesser extent, pig blood facilitated infection, producing …

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Transmission Of Theileria Parva To Cattle By Rhipicephalus Appendiculatus Adults Fed As Nymphae In Vitro On Infected Blood Through An Artificial Membrane, S. M. Waladde, A. S. Young, S. A. Ochieng, S. N. Mwaura, F. N. Kima Jan 1993

Transmission Of Theileria Parva To Cattle By Rhipicephalus Appendiculatus Adults Fed As Nymphae In Vitro On Infected Blood Through An Artificial Membrane, S. M. Waladde, A. S. Young, S. A. Ochieng, S. N. Mwaura, F. N. Kima

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A technique is described for the efficient feeding of Rhipicephalus appendiculatus nymphae on cattle blood through an artificial membrane bearing tactile and olfactory stimuli. The effect of four anticoagulation methods on the feeding of nymphae was compared and heparinized blood was found to be the most efficacious, followed by defibrinated blood. Blood treated with acid citrate dextrose (ACD) or ethylenediamine tetraacetate (EDTA) inhibited nymphal feeding. Nymphae fed on heparinized and defibrinated blood obtained engorgement weights within the range of ticks fed on mammalian hosts and they subsequently moulted and fed normally as adults and produced viable eggs. Nymphae fed on …

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Ultrastructure Of Nosema Marucae Sp. N. (Microspora, Nosematidae), A Pathogen Of Maruca Testulalis (Lepidoptera, Pyralidae), Maurice O. Odindo, Walter G.Z.O. Jura Dec 1992

Ultrastructure Of Nosema Marucae Sp. N. (Microspora, Nosematidae), A Pathogen Of Maruca Testulalis (Lepidoptera, Pyralidae), Maurice O. Odindo, Walter G.Z.O. Jura

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The development of Nosema marucae was followed in its host, the legume pod borer Maruca testulalis. The meronts had an irregular cell body and were binucleated, with the large diplokaryon occupying most of the cell. The sporonts contained many rough endoplastic reticula. The sporoblasts had a granular cytoplasm with a large number of ribosomes, and nuclear division and cellular cleavage were prevalent, particularly from 84 to 120 h after inoculation. Sporoblasts and young spores were evident from 108 to 144 h after inoculation. In the mature spores, the exocuticle had a rough and sculptured surface and the endocuticle thinned considerably …

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Isozyme Analysis Of Kenyan Phlebotomine Sandflies (Diptera: Ppsychodidae) By Isoelectric Focusing (Ief) On Pharmacia Phast System™, H. Mahamat, A. Hassanali, H. Morgan, M. J. Mutinaga, S. Mihok, N. N. Massamba Oct 1992

Isozyme Analysis Of Kenyan Phlebotomine Sandflies (Diptera: Ppsychodidae) By Isoelectric Focusing (Ief) On Pharmacia Phast System™, H. Mahamat, A. Hassanali, H. Morgan, M. J. Mutinaga, S. Mihok, N. N. Massamba

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The isoenzyme profiles of nine sandfly species (Phlebotomus duboscqi, P. elegonensi, P. martini, P. pedifer, Sergentomiya antennatus, S. bedfordi, S. garnhami, S. graingeri and S. schwetzi) from Kenya collected from the field and reared in the Medical Vectors Research Programme of the ICIPE were determined by isoelectric focusing (IEF) on mini ultra-thin polyacrylamide gels supplied by Pharmacia. Three of the nine isoenzymes screened (MDH, G-6-PD, PGM, ME, ICD, GAPDH, 6-PDG, HK and GPI), namely GPI, PGM and ME, gave banding patterns of taxonomic value. Cluster analysis of the simple matching coefficients gave two distinct groupings corresponding to previously described Sergentomyia …

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Inhibitory Effect Of Trypanosoma Brucei Brucei On Glossina Morsitans Midgut Trypsin In Vitro, M. O. Imbuga, E. O. Osir, V. L. Labongo Apr 1992

Inhibitory Effect Of Trypanosoma Brucei Brucei On Glossina Morsitans Midgut Trypsin In Vitro, M. O. Imbuga, E. O. Osir, V. L. Labongo

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The ability of Trypanosoma brucei brucei to inhibit trypsin or trypsin-like enzymes in crude midgut homogenates of Glossina morsitans morsitans was studied in vitro. The isolated parasites caused a concentration-dependent decrease in midgut trypsin activity. Furthermore, trypanosomes lysed by repeated freeze-thawing had a similar effect on trypsin activity. In both cases, the inhibition by either intact or lysed parasites was partial as revealed by Dixon plots. Similarly, trypanosome membrane proteins stoichiometrically inhibited trypsin activity, suggesting that the enzyme interacts specifically with a moiety on the parasite surface. The Km and Ki values obtained in this case were 35 μm and …

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Ultrastructural Studies On The Transovarial Transmission Of Nosema Marucae In Chilo Partellus Swinh, J. A. Ogwang, M. O. Odinho Apr 1992

Ultrastructural Studies On The Transovarial Transmission Of Nosema Marucae In Chilo Partellus Swinh, J. A. Ogwang, M. O. Odinho

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Sublethally infected adults of Chilo partellus Swinhoe were allowed to mate in experimental cages. The mated gravid females were dissected and specific tissues including eggs were removed and examined under both light and electron microscopes. Males were similarly dissected and examined under a ligh microscope only. Results showed that infected males did not transmit Nosema marucae Odindo and Jura venereally. Microscopic studies revealed that N. marucae was transmitted through contamination of the egg chorion. No spores were seen in the yolk neither were spores seen in the spermathecae. The significance of these studies is discussed. © 1992 Verlag Paul Parey.

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Life Tables And Intrinsic Rate Of Natural Increase Of Pediobius Furvus [Hym.: Eulophidae] On Chilo Partellus [Lep.: Pyralidae], G. W. Oloo Mar 1992

Life Tables And Intrinsic Rate Of Natural Increase Of Pediobius Furvus [Hym.: Eulophidae] On Chilo Partellus [Lep.: Pyralidae], G. W. Oloo

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In the present studies, life table data and intrinsic rate of natural increase (rm) of the eulophid pupal parasitoid, P. furvus (Gahan) were obtained from Chilo partellus (Swinhoe) at a constant temperature of 26.7±0.6°C, 52.3±2.7% RH in the laboratory. Development of immature stages took 19.1±0.3 days; adult females lived for 7.9±3.3 (range, 2-13) days and produced a mean of 91.9±22.4 progeny per female, with a sex ratio of 1:2.9 (♂:♀). The intrinsic rate of natural increase (rm) was 0.2558/female/day; the net reproductive rate (R0), 237.25; the capacity for increase (rc) of 0.252; and the finite rate of increase (λ) of …

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Studies On Naturally Acquired Immunity To African Ticks. Ii. Observations On Cattle Exposed To Rhipicephalus Appendiculatus Under Varying Periods Of Repeated Infestations, Olusegun O. Dipeolu, Abdul O. Mongi, Suliman Essuman, Abimboia O. Amoo, Joseph N. Ndungu Jan 1992

Studies On Naturally Acquired Immunity To African Ticks. Ii. Observations On Cattle Exposed To Rhipicephalus Appendiculatus Under Varying Periods Of Repeated Infestations, Olusegun O. Dipeolu, Abdul O. Mongi, Suliman Essuman, Abimboia O. Amoo, Joseph N. Ndungu

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Groups of Friesian cattle were infested repetedly with Rhipicephalus appendiculatus at weekly intervals (eight infestations) and at intervals of 3 weeks (seven infestations) and 6 weeks (seven infestations). The engorgement weight of adults, nymphs and larvae decreased significantly initially, from the second infestation, but rose significantly at later infestations. This rise was more dramatic with larval instars than with any other. A new method for quantifying the resistance status of animals was introduced; this method showed that the resistance acquired by cattle during 6-weekly reinfestations was more stable than that acquired by cattle during weekly and 3-weekly reinfestations. The criteria …

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Some Aspects Of Mating Behavior Of Glossina Morsitans Morsitans Males Infected With A Dna Virus, Walter G.Z.O. Jura, John O.A. Davies-Cole Jan 1992

Some Aspects Of Mating Behavior Of Glossina Morsitans Morsitans Males Infected With A Dna Virus, Walter G.Z.O. Jura, John O.A. Davies-Cole

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Mating behavior of Glossina morsitans morsitans Westwood males, inoculated with the DNA virus during the third-instar larval stage, and sexual receptivity of females premated with such males were studied in the laboratory. Like normal males, the virus-infected males readily located females and mounted them instantaneously. The mean duration of copulation was similar in both normal and infected groups, and all males in both groups experienced the final jerking phase before separating. The value for the degree of insemination (mean spermathecal value) for the females mated with normal males was significantly greater than that for the flies mated with the virus-infected …

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Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). I. Incidence Of Aphids, M. W. Ogenga-Latigo, J. K.O. Ampofo, C. W. Baliddawa Jan 1992

Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). I. Incidence Of Aphids, M. W. Ogenga-Latigo, J. K.O. Ampofo, C. W. Baliddawa

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Investigations were carried out in the field and in the glasshouse to asses the influence of row spacing of intercrop maize on the incidence of the bean aphid, Aphis fabae Scop. (Homoptera: Aphididae), on common beans, Phaseolus vulgaris L., and on aphid dispersal within the intercrops. Maize was planted in the field twice at a 3-week interval, at row spacings of 0.5, 1.0, 1.5 and 2.0 m, while sole and intercropped beans were planted simultaneously with the second maize, at a row spacing of 0.5 m. Aphis fabae incidence was lower on beans intercropped with densely planted maize, with strong …

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Field Evaluation Of Tilapia Zilli (Gervais) As A Biological Control Agent For Mosquito Control, E. J. Asimeng, M. J. Mutinga Jan 1992

Field Evaluation Of Tilapia Zilli (Gervais) As A Biological Control Agent For Mosquito Control, E. J. Asimeng, M. J. Mutinga

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Tilapia zilli (Gervais), a larvivorous fish identified in the Mwea Rice Irrigation System (Kenya), was evaluated in the field to assess its potential for biological control of mosquito larvae. The study was conducted from October 1991 to April 1992 in experimental ponds constructed at Mbui-Njeru, which is one of the 36 villages in the irrigation scheme. T. zilli was found to be extremely effective in controlling mosquito breeding that persisted throughout the study period. However, the presence of vegetation and turbidity significantly reduced its efficiency in predation. The negative effects of vegetation could be averted by combining T. zilli with …

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Factors Affecting Seasonal Dispersal Of The Tsetse Flies Glossina Pallidipes And G. Longipennis (Diptera: Glossinidae) At Nguruman, South-West Kenya, R. Brightwell, R. D. Dransfield, B. G. Williams Jan 1992

Factors Affecting Seasonal Dispersal Of The Tsetse Flies Glossina Pallidipes And G. Longipennis (Diptera: Glossinidae) At Nguruman, South-West Kenya, R. Brightwell, R. D. Dransfield, B. G. Williams

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Seasonal changes in the distribution of the tsetse flies, Glossina pallidipes Austen and G. longipennis Corti, along a transect from riverine thickets out into open plains were monitored along with tsetse density, climatic factors, vegetation and host abundance. Dispersal of tsetse into open country was quantified using the mean spread. During and after the rains both species extended their distribution out into open country up to at least 3.5 km from riverine thicket areas. The mean spread of G. longipennis was greater than that of G. pallidipes. The spread of males and females was very similar, as was the spread …

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Influence Of Exposure Period And Management Methods On The Effectiveness Of Chickens As Predators Of Ticks Infesting Cattle, S. M. Hassan, O. O. Dipeolu, D. M. Munyinyi Jan 1992

Influence Of Exposure Period And Management Methods On The Effectiveness Of Chickens As Predators Of Ticks Infesting Cattle, S. M. Hassan, O. O. Dipeolu, D. M. Munyinyi

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Experiments undertaken on Rusinga Island, Kenya, indicated that Rhipicephalus appendiculatus (Neumann) was the predominant tick consumed on tick-infested cattle by chickens, followed by Amblyomma variegatum (Fabricius), Boophilus decoloratus (Koch) and Rhipicephalus evertsi evertsi (Neumann). The number of ticks consumed by chickens released with cattle in a 3 h release period was not significantly different from ticks consumed in a 4 h release period. In a free management system, chickens 1-3 months of age consumed more ticks than older ones; in a confined management system however, chickens 4-6 months of age consumed more ticks than younger birds. Although the numbers of …

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Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). Ii. Reduction In Bean Yields, M. W. Ogenga-Latigo, C. W. Baliddawa, J. K.O. Ampofo Jan 1992

Influence Of Maize Row Spacing On Infestation And Damage Of Intercropped Beans By The Bean Aphid (Aphis Fabae Scop.). Ii. Reduction In Bean Yields, M. W. Ogenga-Latigo, C. W. Baliddawa, J. K.O. Ampofo

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Field studies were conducted to assess the effects of intercropping common beans (Phaseolus vulgaris L.) with maize (Zea mays L.), at two growth stages and four row spacings (0.5, 1.0, 1.5 and 2.0 m), on Aphis fabae infestation of beans and on the magnitudes of bean yield losses due to aphid attack and to competition by maize. The first maize planting (Old maize) was carried out 3 weeks earlier than beans, while the second planting (Young maize) was done simultaneously with beans. Significantly (P < 0.05) fewer plants were infested by A. fabae when beans were intercropped with older or densely planted maize. Aphid colonies on beans were also smaller, and there was reduced aphid damage to beans in the intercrops. However, whereas bean yield loss from aphid attack was less than 3.5% in all intercrop situations, yield loss from competition by maize was very high, being up to 98% when beans were intercropped with early-planted maize at 0.5-m row spacing. Yields of intercropped maize planted at row spacings of 0.5, 1.5 and 2.0 m were also depressed. The results show that both maize growth and row spacing could be exploited for the control of A. fabae on intercropped beans. However, adequate consideration must be given to the negative effects of maize planting density and growth on yields of both crops. © 1992.

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Larval Development Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) On Artificial Diet Incorporating Leaf Tissues Of Sorghum Lines In Relation To Their Resistance Or Susceptibility, Kailash Narain Saxena Jan 1992

Larval Development Of Chilo Partellus (Swinhoe) (Lepidoptera: Pyralidae) On Artificial Diet Incorporating Leaf Tissues Of Sorghum Lines In Relation To Their Resistance Or Susceptibility, Kailash Narain Saxena

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This study was taken up to examine the relationship between the susceptibility or resistance of six sorghum lines to Chilo partellus and dietary quality of their leaf tissues, incorporated in an artificial diet, to support larval development. The diets tested were agar based basic medium with or without cellulose powder, dry leaf powder or fresh leaf-paste of the sorghum lines. The basic medium alone or with cellulose powder showed the poorest dietary quality in-as-much as it did not support more than 26–32% larval development. The tolerant sorghum IS 18520 leaf tissues, incorporated in the artificial diet as dry powder or …

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Influence Of Temperature On In Vitro Growth Of Entomopathogenic Hyphomycetes, J. Fargues, Nk Maniania, Jc Delmas, N. Smits Jan 1992

Influence Of Temperature On In Vitro Growth Of Entomopathogenic Hyphomycetes, J. Fargues, Nk Maniania, Jc Delmas, N. Smits

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Thirty-one isolates of 6 entomopathogenic hyphomycetes, Beauveria bassiana (Balsamo) Vuillemin, B brongniartii (= tenella; (Saccardo) Petch, Metarhizium anisopliae (Metschnikoff) Sorokin, M flavoviride Gams et Rozsypal, Nomuraea rileyi (Farlow) Samsom and Paecilomyces fumosoroseus (Wize) Brown et Smith, were grown in vitro to determine growth rates and ranges of growth at 10 temperatures from 8 to 37 °C in the dark. Radial growth of surface colonies on semisynthetic nutrient agar was recorded by daily measurement of 2 cardinal diameters. Because radial measurements (from day 3 to 12) of surface colonies for each temperature fit a linear model (y = vt+b), growth rates …

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Oviposition, Larval Arrest And Establishment Of Chilo Partellus (Lepidoptera: Pyralidae) On Maize Genotypes During Anthesis, Harish Kumar Jan 1992

Oviposition, Larval Arrest And Establishment Of Chilo Partellus (Lepidoptera: Pyralidae) On Maize Genotypes During Anthesis, Harish Kumar

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The oviposition, larval arrest and establishment by the stem borer Chilo partellus (Swinhoe) were measured on different maize genotypes during anthesis. The maize genotypes tested were: Inbred A (Susceptible), Mp 704, MBR-8637, MBR-8650, MBR-8668, Poza Rica 7832, ER-29 SVR, Katumani Composite B, MMV 400, Bulk CG 4141, and ICZ2-CM. The moths oviposited on the middle leaves of the plant and the neonate larvae moved to leaf sheaths and ear husks to feed (arrest). As they grew older, the larvae invaded the stem, ear shanks and tassel to complete feeding (establishment) and to pupate. The response of the stem borer differed …

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Eclosion Behavior In Tsetse (Diptera: Glossinidae): Extrication From The Puparium And Expansion Of The Adult, Jan Zdárek, David L. Denlinger Jan 1992

Eclosion Behavior In Tsetse (Diptera: Glossinidae): Extrication From The Puparium And Expansion Of The Adult, Jan Zdárek, David L. Denlinger

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The tsetse adult extricates itself from the puparium and surrounding substrate by a series of muscular contractions that generate a Stereotypic pattern of changes in hemolymph pressure. The digging action of the fly can be distinguished from a second pattern of hemocoelic pulsations that is used to remove obstacles from its path. When the fly is restrained extrication behavior will persist for over 10 h. If the adult's legs are freed while the remainder of the body remains encased in the puparium, the fly fails to engage in extrication behavior, a result which suggests that freedom of the legs switches …

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