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Articles 931 - 960 of 1129

Full-Text Articles in Entomology

Host Specificity Of Psyttalia Cosyrae (Hymenoptera: Braconidae) And The Effect Of Different Host Species On Parasitoid Fitness, Samira A. Mohamed, William A. Overholt, Robert A. Wharton, Slawomir A. Lux, Elameen M. Eltoum Jan 2003

Host Specificity Of Psyttalia Cosyrae (Hymenoptera: Braconidae) And The Effect Of Different Host Species On Parasitoid Fitness, Samira A. Mohamed, William A. Overholt, Robert A. Wharton, Slawomir A. Lux, Elameen M. Eltoum

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Psyttalia cosyrae (Wilkinson) (Hymenoptera: Braconidae) is a synovigenic, koinobiont larval-pupal parasitoid of Ceratitis cosyra (Walker) (Diptera: Tephritidae), and possibly other tephritid fruit flies. Host acceptance and suitability of medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), mango fruit fly, Ceratitis cosyra, Natal fruit fly, Ceratitis rosa Karsch, Ceratitis fasciventris (Bezzi), Ceratitis anonae Graham, and melon fruit fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), for oviposition and development of this parasitoid were investigated. The effect of different host species on traits widely used to assess parasitoid fitness was also evaluated. Psyttalia cosyrae accepted all host species tested, but acceptance varied. In no choice tests, …

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Spatial And Temporal Heterogeneity Of Anopheles Mosquitoes And Plasmodium Falciparum Transmission Along The Kenyan Coast, Charles M. Mbogo, Joseph M. Mwangangi, Joseph G. Nzovu, Weidong Gu, Guiyan Yan, James T. Gunter, Chris Swalm, Joseph Keating, James L. Regens, Josephat I. Shililu, John I. Githure, John C. Beier Jan 2003

Spatial And Temporal Heterogeneity Of Anopheles Mosquitoes And Plasmodium Falciparum Transmission Along The Kenyan Coast, Charles M. Mbogo, Joseph M. Mwangangi, Joseph G. Nzovu, Weidong Gu, Guiyan Yan, James T. Gunter, Chris Swalm, Joseph Keating, James L. Regens, Josephat I. Shililu, John I. Githure, John C. Beier

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The seasonal dynamics and spatial distributions of Anopheles mosquitoes and Plasmodium falciparum parasites were studied for one year at 30 villages in Malindi, Kilifi, and Kwale Districts along the coast of Kenya. Anopheline mosquitoes were sampled inside houses at each site once every two months and malaria parasite prevalence in local school children was determined at the end of the entomologic survey. A total of 5,476 Anopheles gambiae s.l. and 3,461 An. funestus were collected. Species in the An. gambiae complex, identified by a polymerase chain reaction, included 81.9% An. gambiae s.s., 12.8% An. arabiensis, and 5.3% An. merus. Anopheles …

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Malariasphere: A Greenhouse-Enclosed Simulation Of A Natural Anophelesgambiae (Diptera: Culicidae) Ecosystem In Western Kenya, Bart G.J. Knols, Basilio N. Njiru, Evan M. Mathenge, Wolfgang R. Mukabana, John C. Beier, Gerry F. Killeen Dec 2002

Malariasphere: A Greenhouse-Enclosed Simulation Of A Natural Anophelesgambiae (Diptera: Culicidae) Ecosystem In Western Kenya, Bart G.J. Knols, Basilio N. Njiru, Evan M. Mathenge, Wolfgang R. Mukabana, John C. Beier, Gerry F. Killeen

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Background: The development and implementation of innovative vector control strategies for malaria control in Africa requires in-depth ecological studies in contained semi-field environments. This particularly applies to the development and release of genetically-engineered vectors that are refractory to Plasmodium infection. Here we describe a modified greenhouse, designed to simulate a natural Anopheles gambiae Giles ecosystem, and the first successful trials to complete the life-cycle of this mosquito vector therein. Methods: We constructed a local house, planted crops and created breeding sites to simulate the natural ecosystem of this vector in a screen-walled greenhouse, exposed to ambient climate conditions, in western …

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Morphology Of The Minute Larva Of Ptinella Tenella, With Special Reference To Effects Of Miniaturisation And The Systematic Position Of Ptiliidae (Coleoptera: Staphylinoidea), Vasily V. Grebennikov, Rolf G. Beutel Nov 2002

Morphology Of The Minute Larva Of Ptinella Tenella, With Special Reference To Effects Of Miniaturisation And The Systematic Position Of Ptiliidae (Coleoptera: Staphylinoidea), Vasily V. Grebennikov, Rolf G. Beutel

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External and internal features of minute reared ex ovo larvae of Ptinella tenella Erichson with the head widths ranging from 108 to 138 μm are described. In total 139 setae (trichoid sensilla), 18 pores (non-trichoid sensilla), and 60 muscles were identified. The complexity of the chaetotaxy, the musculature of the head, the tentorium, and the digestive tract are not affected by the extremely small size of the larvae. Specific features, which may have resulted from miniaturisation are the elongate shape of the brain reaching the mesothorax posteriorly, the reduced condition of the thoracic sclerites and endosternites, the simplified musculature of …

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Relative Safety Of Sprays Of Two Neem Insecticides To Diadegma Mollipla (Holmgren), A Parasitoid Of The Diamondback Moth: Effects On Adult Longevity And Foraging Behaviour, A. M. Akol, S. Sithanantham, P. G.N. Njagi, A. Varela, J. M. Mueke Nov 2002

Relative Safety Of Sprays Of Two Neem Insecticides To Diadegma Mollipla (Holmgren), A Parasitoid Of The Diamondback Moth: Effects On Adult Longevity And Foraging Behaviour, A. M. Akol, S. Sithanantham, P. G.N. Njagi, A. Varela, J. M. Mueke

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The non-target safety of two neem-based insecticides, Neemroc EC® (an oil formulation) and Neemros® (an oil-free powder formulation) to adults of Diadegma mollipla (Holmgren), a larval parasitoid of the diamondback moth, Plutella xylostella (L.), was investigated in laboratory bioassays. The neem insecticides were compared against Karate® (a synthetic pyrethroid insecticide) and water as sprays. Karate® caused 100% mortality in treated wasps within 6 h, while the two neem insecticides did not cause any significant mortality. The mean longevity of wasps was not significantly affected by exposure to the two neem insecticides. The time allocation to different components of foraging behaviour …

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The Development Of A Multipurpose Trap (The Nzi) For Tsetse And Other Biting Flies, S. Mihok Oct 2002

The Development Of A Multipurpose Trap (The Nzi) For Tsetse And Other Biting Flies, S. Mihok

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New trap designs for tsetse (Glossinidae), stable flies (Muscidae: Stomoxyinae), and horse flies (Tabanidae) were tested in Kenya to develop a multipurpose trap for biting flies. Many configurations and colour/fabric combinations were compared to a simplified, blue-black triangular trap to identify features of design and materials that result in equitable catches. New designs were tested against conventional traps, with a focus on Glossina pallidipes Austen and G. longipennis Corti, Stomoxys niger Macquart, and Atylotus agrestis (Wiedemann). A simple design based on minimal blue and black rectangular panels, for attraction and contrast, with a trap body consisting of an innovative configuration …

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Wolbachia Infection In Cotesia Sesamiae (Hymenoptera: Braconidae) Causes Cytoplasmic Incompatibility: Implications For Biological Control, Moses B. Mochiah, Adele J. Ngi-Song, William A. Overholt, Richard Stouthamer Sep 2002

Wolbachia Infection In Cotesia Sesamiae (Hymenoptera: Braconidae) Causes Cytoplasmic Incompatibility: Implications For Biological Control, Moses B. Mochiah, Adele J. Ngi-Song, William A. Overholt, Richard Stouthamer

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Cotesia sesamiae (Hymenoptera: Braconidae) is an indigenous, gregarious, larval endoparasitoid that attacks mid- to late-instar of the stem borer larvae. Although the parasitoid is distributed widely throughout Africa, not all local populations appear to be equally effective in controlling stem borers. Consequently, there is an interest in releasing the more effective strains in areas that already have very low populations of C. sesamiae. Some C. sesamiae populations are infected with bacterial symbionts in the genus Wolbachia, which may induce cytoplasmic incompatibility. Using an antibiotic treatment, we have established that the Wolbachia infection causes cytoplasmic incompatibility of the female mortality type …

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Repellency Of Live Potted Plants Against Anopheles Gambiae From Human Baits In Semi-Field Experimental Huts, Aklilu Seyoum, Ephantus W. Kabiru, Wilber Lwande, Gerry F. Killeen, Ahmed Hassanali, Bart G.J. Knols Aug 2002

Repellency Of Live Potted Plants Against Anopheles Gambiae From Human Baits In Semi-Field Experimental Huts, Aklilu Seyoum, Ephantus W. Kabiru, Wilber Lwande, Gerry F. Killeen, Ahmed Hassanali, Bart G.J. Knols

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The repellency of potted plants against the malaria vector Anopheles gambiae sensu stricto Giles was quantified in experimental huts under semi-field conditions inside a screen-walled greenhouse. Ocimum americanum Linnaeus (Labiatae), Lantana camara L. (Verbenaceae), and Lippia uckambensis Spreng (Verbenaceae) repelled at an average of 39.7% (95% confidence interval [CI] = 29.6-48.4%), 32.4% (95% CI = 19.7-43.1%), and 33.3% (95% CI = 21.5-43.3%) of the mosquitoes, respectively (P < 0.0001 for all treatments). This was determined by logistic regression, allowing for variations associated with different bait hosts, sampling huts, and replicate test nights. In contrast, Ocimum kilimandscharicum Guerke (Labiatae), Ocimum suave Willd. (Labiatae), Corymbia citriodora Hook (Myrtaceae), Azadirachta indica A. Juss (Meliaceae), Tagetes minuta L. (Asteraceae), and Hyptis suaveolens Poit. (Lamiaceae) did not significantly repel mosquitoes. The combination of O. americanum with either L. camara or L. uckambensis repelled 31.6% (95% CI = 19.7-41.7%) and 45.2% (95% CI = 34.7-54.0%) of the mosquitoes, respectively (P < 0.0001 for both treatments). This study is the first to show that live intact plants can reduce domestic exposure to malaria vector mosquitoes. As such, they may represent a new, sustainable and readily applicable malaria vector control tool for incorporation into integrated vector management programs.

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Ovicidal Activity Of Entomopathogenic Hyphomycetes To The Legume Pod Borer, Maruca Vitrata And The Pod Sucking Bug, Clavigralla Tomentosicollis, S. Ekesi, R. S. Adamu, N. K. Maniania Aug 2002

Ovicidal Activity Of Entomopathogenic Hyphomycetes To The Legume Pod Borer, Maruca Vitrata And The Pod Sucking Bug, Clavigralla Tomentosicollis, S. Ekesi, R. S. Adamu, N. K. Maniania

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The ovicidal activity of eight isolates of entomopathogenic hyphomycetes was evaluated in the laboratory against Maruca vitrata and Clavigralla tomentosicollis. At a concentration of 1 × 108 conidia ml-1, four isolates (Beauveria bassiana CPD 3 and 10, and Metarhizium anisopliae CPD 5 and 12) were found to be highly pathogenic to eggs of M. vitrata, achieving 89-100% mortality. At a given concentration, three isolates (B. bassiana CPD 9 and M. anisopliae CPD 5 and 12) were highly pathogenic to eggs of C. tomentosicollis, achieving 91-94% mortality. These isolates also caused high larval and nymphal mortality (94-100% in M. vitrata and …

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Visual Evaluation And Recognition Of Hosts By The Tick Parasitoid, Ixodiphagus Hookeri (Hymenoptera: Encyrtidae), F. A. Demas, E. N. Mwangi, A. Hassanali, E. C. Kunjeku, A. R. Mabveni Jul 2002

Visual Evaluation And Recognition Of Hosts By The Tick Parasitoid, Ixodiphagus Hookeri (Hymenoptera: Encyrtidae), F. A. Demas, E. N. Mwangi, A. Hassanali, E. C. Kunjeku, A. R. Mabveni

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The role of host size, movement, feeding status, color, and species in the visual host evaluation and recognition behavior of the tick parasitoid, Ixodiphagus hookeri Howard was investigated. Freshly emerged female parasitoids were subjected to a choice bioassay, where the test materials were placed in sealed vials and the vials placed in a Petri dish. When presented with A. variegatum live and mummified nymphs, females examined: larger nymphs significantly longer than smaller nymphs, fed nymphs significantly longer than unfed nymphs, dead and live nymphs for similar lengths of time, and grey live nymphs and yellow-brown and dark brown mummified nymphs …

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Extent Of Digestion Affects The Success Of Amplifying Human Dna From Blood Meals Of Anopheles Gambiae (Diptera: Culicidae), W. R. Mukabana, W. Takken, P. Seda, G. F. Killeen, W. A. Hawley, B. G.J. Knols Jun 2002

Extent Of Digestion Affects The Success Of Amplifying Human Dna From Blood Meals Of Anopheles Gambiae (Diptera: Culicidae), W. R. Mukabana, W. Takken, P. Seda, G. F. Killeen, W. A. Hawley, B. G.J. Knols

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The success of distinguishing blood meal sources of Anopheles gambiae Giles through deoxyribonucleic acid (DNA) profiling was investigated by polymerase chain reaction (PCR) amplification at the TC-11 and VWA human short tandem repeats (STR) loci. Blood meal size and locus had no significant effect on the success of amplifying human DNA from blood meals digested for 0, 8, 16, 24 and 32 h (P = 0.85 and 0.26 respectively). However, logistic regression found a significant negative relationship between time since ingestion and the success probability of obtaining positive PCR products among meals digested for between 8 and 32 h (P …

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Functional Response Of Orius Albidipennis (Hemiptera: Anthocoridae) To Megalurothrips Sjostedti (Thysanoptera: Thripidae), Linus M. Gitonga, W. A. Overholt, B. Löhr, J. K. Magambo, J. M. Mueke Jun 2002

Functional Response Of Orius Albidipennis (Hemiptera: Anthocoridae) To Megalurothrips Sjostedti (Thysanoptera: Thripidae), Linus M. Gitonga, W. A. Overholt, B. Löhr, J. K. Magambo, J. M. Mueke

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A locally available anthocorid predator, Orius albidipennis Reuter, was evaluated as a candidate biocontrol agent for Megalurothrips sjostedti Trybom, a major pest of French beans, Phaseolus vulgaris (L), in Kenya. The functional response of adult O. albidipennis to larval and adult M. sjostedti was studied at 15, 25, and 28°C and densities of 5, 10, 20, and 30 larval and adult M. sjostedti per cage, over 24 h. More larvae and adult M. sjostedti were killed at the higher densities and with an increase in temperature. The data provided good fit to both type I and II functional response models. …

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Odor Composition Of Preferred (Buffalo And Ox) And Nonpreferred (Waterbuck) Hosts Of Some Savanna Tsetse Flies, Nicholas K. Gikonyo, Ahmed Hassanali, Peter G.N. Njagi, Peter M. Gitu, Jacob O. Midiwo May 2002

Odor Composition Of Preferred (Buffalo And Ox) And Nonpreferred (Waterbuck) Hosts Of Some Savanna Tsetse Flies, Nicholas K. Gikonyo, Ahmed Hassanali, Peter G.N. Njagi, Peter M. Gitu, Jacob O. Midiwo

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A previous study on the feeding responses of tsetse flies, Glossina morsitans morsitans, implicated the existence of allomonal barriers, both volatile and nonvolatile, on the nonpreferred host, waterbuck, Kobus defassa. In the present study, electroantennogram-active compounds in odors from waterbuck were compared with those of two preferred hosts of tsetse flies, buffalo, Syncerus caffer, and ox, Bos indicus. Odors from the three bovids were trapped on activated charcoal and/or reverse-phase (octadecyl bonded) silica and analyzed with a gas chromatography- linked electroantennographic detector (GC-EAD) and, where possible, identified by using gas chromatography-linked mass spectrometry (GC-MS) and chromatographic comparisons with authentic samples. …

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Evidence For A Compound In Comstock-Kellog Glands Modulating Premating Behavior In Male Desert Locust, Schistocerca Gregaria, Peter G.N. Njagi, B. Torto May 2002

Evidence For A Compound In Comstock-Kellog Glands Modulating Premating Behavior In Male Desert Locust, Schistocerca Gregaria, Peter G.N. Njagi, B. Torto

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The Comstock-Kellog glands in adult females of certain acridid species, including the desert locust, Schistocerca gregaria have been implicated as a source of volatiles that play a role in mating behavior. A dichloromethane extract of the glands was analyzed for metabolites by gas chromatography, coupled gas chromatography-electroantennographic detection, and mass spectrometry. Coupled gas chromatography-electroantennographic detector (GC-EAD) analysis revealed a component that elicited an electroantennogram response from the antenna of adult male S. gregaria. The compound was identified by GC-MS as pentanoic acid. The levels of the compound in the gland extract varied with age of female locust; it was present …

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Characterization Of A Unique Human Single-Chain Antibody Isolated By Phage-Display Selection On Membrane-Bound Mosquito Midgut Antigens, Brian D. Foy, Gerry F. Killeen, Ross H. Frohn, Daniel Impoinvil, Andrew Williams, John C. Beier Mar 2002

Characterization Of A Unique Human Single-Chain Antibody Isolated By Phage-Display Selection On Membrane-Bound Mosquito Midgut Antigens, Brian D. Foy, Gerry F. Killeen, Ross H. Frohn, Daniel Impoinvil, Andrew Williams, John C. Beier

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The insect midgut is the primary site for food digestion, as well as for vector-borne pathogen infection into the invertebrate host. Accordingly, antigens of this critical insect organ are targets for anti-vector vaccines, insecticidal toxins, and transmission-blocking vaccines. We used midgut proteins of the African malaria vector mosquito Anopheles gambiae to select single-chain human antibody fragments (scFv) from a high-diversity, phage-displayed library. Using a phage-display selection method on western-blotted antigens, we selected an unusual truncated scFv clone, consisting of a heavy-chain only, which binds to An. gambiae midgut tissue. This clone binds a spectrum of mosquito antigens from the midgut …

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Description Of The First-Instar Larva Of Geocharidius (Coleoptera: Carabidae: Trechitae) With A Discussion Of The Phylogeny Of The Subtribe Anillina, Vasily V. Grebennikov Jan 2002

Description Of The First-Instar Larva Of Geocharidius (Coleoptera: Carabidae: Trechitae) With A Discussion Of The Phylogeny Of The Subtribe Anillina, Vasily V. Grebennikov

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This paper describes the first-instar larva of Geocharidius Jeannel, a species from Mexico, which is the second record of an Anillina (Coleoptera: Carabidae: Trechitae) larva; previously described was a species of the European genus Typhlocharis. Larvae of these two genera share ten synapomorphic characters, which support the monophyletic origin of Anillina. Sister-group relationships of Anillina with Tachyina + Xystosomina are proposed on the basis of three shared larval synapomorphies: seta LA5 of ligula absent; coronal suture in first-instar larvae very short or absent; second- third-instar larvae have none or one secondary seta on lateral sides of stipes and labium and …

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Density Effects Of The Banana Weevil, Cosmopolites Sordidus (Germar), On Its Oviposition Performance And Egg And Larval Survivorship, Clifford S. Gold, Godfrey H. Kagezi, Pontiano Nemeye, Philip E. Ragama Jan 2002

Density Effects Of The Banana Weevil, Cosmopolites Sordidus (Germar), On Its Oviposition Performance And Egg And Larval Survivorship, Clifford S. Gold, Godfrey H. Kagezi, Pontiano Nemeye, Philip E. Ragama

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The influence of banana weevil, Cosmopolites sordidus (Germar)(Coleoptera: Curculionidae), population density on oviposition rates and larval survivorship was studied in the laboratory at the Kawanda Agricultural Research Institute in Uganda. This study was undertaken to elucidate the relationship between density-dependent factors and rates of banana weevil increase in the field. Oviposition substrates (corm pieces) were offered to a range of densities of weevils maintained in buckets. Mean oviposition rates per female at densities of 10, 20 and 40 females per bucket were 29, 37 and 53%, respectively, lower than that at a density of 5 females. Nevertheless, total oviposition for …

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Effects Of Calyx Fluid From A Population Of Cotesia Sesamiae (Cameron) (Hymenoptera: Braconidae) On The Immune Response Of Its Host Busseola Fusca Fuller (Lepidoptera: Noctuidae), Moses B. Mochiah, Adele J. Ngi-Song, William A. Overholt, M. Botchey Jan 2002

Effects Of Calyx Fluid From A Population Of Cotesia Sesamiae (Cameron) (Hymenoptera: Braconidae) On The Immune Response Of Its Host Busseola Fusca Fuller (Lepidoptera: Noctuidae), Moses B. Mochiah, Adele J. Ngi-Song, William A. Overholt, M. Botchey

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Busseola fusca Fuller is one of the major lepidopteran stemborers of maize and sorghum in Africa. Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) is an indigenous, gregarious larval endoparasitoid that attacks mid- to late-instar stemborer larvae, which is reported to be one of the most important larval parasitoids of B. fusca in many countries in sub-Saharan Africa. Previous work has shown that two biotypes of C. sesamine occur in Kenya which express differential abilities to develop in B. fusca. A biotype from western Kenya successfully develops in B. fusca, while a biotype from the eastern coastal area does not. We treated fourth-instars …

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Effect Of Temperature On The Development Of Orius Albidipennis Reuter, A Predator Of The African Legume Flower Thrips, Megalurothrips Sjostedti Trybom, L. M. Gitonga, B. Löhr, W. A. Overholt, J. K. Magambo, J. M. Mueke Jan 2002

Effect Of Temperature On The Development Of Orius Albidipennis Reuter, A Predator Of The African Legume Flower Thrips, Megalurothrips Sjostedti Trybom, L. M. Gitonga, B. Löhr, W. A. Overholt, J. K. Magambo, J. M. Mueke

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The effects of temperature on the development of Orius albidipennis (Reuter) (Hemiptera: Anthocoridae), reared on its prey, Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), were studied in the laboratory. Nymphal mortality was 87, 48 and 38% at 20, 25 and 30 °C, respectively. With the exception of first-instar nymphs, percentage mortality was lowest at 25 °C. Pre-oviposition period and longevity decreased with an increase in temperature. Mean daily and total fecundity were 2.1 and 76.4 respectively at 25 °C. The mean developmental period from oviposition to adult eclosion was 27.7, 14.1 and 10.9 days at 20, 25 and 30 °C respectively. There …

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Predicting The Distribution Of Chilo Partellus (Swinhoe) And Its Parasitoid Cotesia Flavipes Cameron In Ethiopia Using Correlation, Step-Wise Regression And Geographic Information Systems, G. Emana, W. A. Overholt, E. Kairu, L. Macopiyo, G. Zhou Jan 2002

Predicting The Distribution Of Chilo Partellus (Swinhoe) And Its Parasitoid Cotesia Flavipes Cameron In Ethiopia Using Correlation, Step-Wise Regression And Geographic Information Systems, G. Emana, W. A. Overholt, E. Kairu, L. Macopiyo, G. Zhou

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The recent development of geographic information systems (GIS) provides new avenues for analysing spatial patterns in insect populations. Field survey data, along with GIS and statistical models were used to predict the distribution of Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) and Cotesia flavipes Cameron (Hymenoptera: Braconidae) in Ethiopia. The results obtained suggested that the distributions of Ch. parlellus and Co. flavipes were affected by rainfall and temperature. The predicted distributions of Ch. parlellus and Co. flavipes were similar. Validation of predicted values is discussed. © 2002 ICIPE.

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Comparative Evaluation Of The Efficacy Of Aqueous Neem Extract And Dipel 2x On Diamondback Moth, Plutella Xylostella Linn., On Cabbage In Kenya, S. Okoth, C. K.P. Ogol, M. Basimike, M. Varela Jan 2002

Comparative Evaluation Of The Efficacy Of Aqueous Neem Extract And Dipel 2x On Diamondback Moth, Plutella Xylostella Linn., On Cabbage In Kenya, S. Okoth, C. K.P. Ogol, M. Basimike, M. Varela

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The efficacy of neem kernel cake powder water extract (NKCP-WE) and Dipel 2x (Bacillus thuringiensis var. kurstaki) in controlling the diamondback moth (DBM), Plutella xylostella Linn. (Lepidoptera: Yponomeutidae), on cabbage was evaluated in screenhouse experiments. All concentrations of NKCP-WE tested were larvicidal and plants treated with 25 and 50 g/l NKCP-WE retained larvicidal activity for up to 2 weeks after application. The efficacy of 25 and 50 g/l NKCP-WE and 0.5 g/l Dipel 2x was compared by observing DBM development on the treated plants and yields of those plants. Dipel 2x-treated plants had less DBM larval infestation than the neem-treated …

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Comparative Development And Population Growth Of An Exotic Stemborer, Chilo Partellus (Swinhoe), And An Ecologically Similar Congener, C. Orichalcociliellus (Strand) (Lepidoptera: Crambidae), Jacob C. Mbapila, William A. Overholt, Hosea Y. Kayumbo Jan 2002

Comparative Development And Population Growth Of An Exotic Stemborer, Chilo Partellus (Swinhoe), And An Ecologically Similar Congener, C. Orichalcociliellus (Strand) (Lepidoptera: Crambidae), Jacob C. Mbapila, William A. Overholt, Hosea Y. Kayumbo

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Studies were conducted to determine the effect of temperature and diet on the development of Chilo partellus (Swinhoe) and Chilo orichalcociliellus (Strand) (Lepidoptera: Crambidae). Developmental times of C. partellus and C. orichalcociliellus for the egg, larval and egg-adult life stages were inversely related to temperature. The larval developmental period of C. orichalcociliellus reared on artificial diet was longer than the developmental period on natural diet. Chilo partellus had a higher intrinsic rate of natural increase than C. orichalcociliellus at all diet/temperature combinations except natural diet at 31°C. © 2002 ICIPE.

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Evidence Of Adaptation Of Diamondback Moth, Plutella Xylostella (L.), To Pea, Pisum Sativum L., Bernhard Löhr, Ruth Gathu Jan 2002

Evidence Of Adaptation Of Diamondback Moth, Plutella Xylostella (L.), To Pea, Pisum Sativum L., Bernhard Löhr, Ruth Gathu

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A strain of diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), adapted to peas was detected in 1999 in the export vegetable growing area south of Lake Naivasha in the Rift Valley Province of Kenya. The pea strain (DBM-P) was compared in laboratory studies to the normal crucifer strain (DBM-C). Whereas DBM-P performed comparably well on kales and peas, the cabbage strain (DBM-C) suffered heavy mortality on peas. Out of the 250 DBM-C first instars, only six reached adult stage on pea. In addition, larval development was prolonged by five days on peas as compared to kale, and larval growth …

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Comparative Life Table Statistics Of Exochomus Flaviventris Reared On The Cassava Mealybug, Phenacoccus Manihoti, Fed On Four Host Plants, B. P. Le Rü, A. Mitsipa Jan 2002

Comparative Life Table Statistics Of Exochomus Flaviventris Reared On The Cassava Mealybug, Phenacoccus Manihoti, Fed On Four Host Plants, B. P. Le Rü, A. Mitsipa

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The demographic statistics of the ladybird Exochomus flaviventris Mader (Coleoptera: Coccinellidae) were investigated under laboratory conditions on the cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Homoptera: Pseudococcidae), reared on four host plants with different levels of antibiotic resistance to the mealybug: two cassava (Manihot esculenta Crantz, Euphorbiaceae) varieties, Incoza and Zanaga, Faux-Caoutchouc (FC) (hybrid of M. esculenta x M. glaziovii Muel. Arg.) and water weed (Talinum triangulare Jack, Portulacacae). Preimaginal mortality, mean oviposition time and total fecundity of female ladybirds were strongly affected by the host plant even though there was no linkage with antibiotic resistance. The net reproduction rates R o …

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Laboratory Evaluation Of The Entomopathogenic Fungus, Metarhizium Anisopliae For The Control Of The Groundnut Bruchid, Caryedon Serratus On Groundnut, S. Ekesi, E. A. Egwurube, A. D. Akpa, I. Onu Nov 2001

Laboratory Evaluation Of The Entomopathogenic Fungus, Metarhizium Anisopliae For The Control Of The Groundnut Bruchid, Caryedon Serratus On Groundnut, S. Ekesi, E. A. Egwurube, A. D. Akpa, I. Onu

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The pathogenicity of five isolates of Metarhizium anisopliae to adult Caryedon serratus was evaluated in the laboratory. All the isolates tested were virulent to the beetle but pathogenicity varied among the isolates. One isolate, CPD 4 was consistently superior to all other isolates in terms of mortality of the beetle, protection of groundnut pods from damage, reduction in progeny production and repellency to the beetle. At 10 days post-treatment, adult mortality treated with 0.1, 0.5 and 1.0 g of dry conidia equivalent to 3.6 × 108, 1.8 × 109 and 3.6 × 109 conidia of isolate CPD 4 per 50 …

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Modelling The Trappability Of Tsetse, Glossina Fuscipes Fuscipes, In Relation To Distance From Their Natural Habitats, Adedapo Odulaja, Mohamed M. Mohamed-Ahmed Sep 2001

Modelling The Trappability Of Tsetse, Glossina Fuscipes Fuscipes, In Relation To Distance From Their Natural Habitats, Adedapo Odulaja, Mohamed M. Mohamed-Ahmed

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The log-logistic probability distribution function was employed to model trappability of Glossina fuscipes fuscipes, with respect to distance from the edge of two types of habitat. The parameters of the model were obtained using the nonlinear maximum likelihood approach. Asymptotic standard errors of the maximum likelihood estimates were computed for the parameters, and the X2 goodness-of-fit test used to assess the predicted trap catches. Simulation technique was used to estimate the radius of attraction of the unbaited biconical trap for the fly, taking the efficiency of the trap into consideration. The log-logistic model fitted well to a series of observed …

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Predators Of Mesoplatys Ochroptera In Sesbania Planted-Fallows In Eastern Zambia, G. Sileshi, M. Kenis, C. K.P.O. Ogol, S. Sithanantham Aug 2001

Predators Of Mesoplatys Ochroptera In Sesbania Planted-Fallows In Eastern Zambia, G. Sileshi, M. Kenis, C. K.P.O. Ogol, S. Sithanantham

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Mesoplatys ochroptera Stål (Coleoptera: Chrysomelidae) is a serious pest of the tropical legume sesbania (Sesbania sesban (L.) Merrill) widely used for soil fertility improvement in southern Africa. Surveys were conducted between October 1997 and June 1999 in order to identify the predators of M. ochroptera in sesbania fallows in eastern Zambia. The Heteroptera Afrius yolofa (Guérin-Méneville), Glypsus conspicuus (Westwood), Macrorhaphis acuta Dallas, Mecosoma mensor (Germar), Rhinocoris segmentarius (Germar), and Deraeocoris ostentans (Stål), the carabid beetle Cyaneodinodes fasciger (Chaudoir), the ants Tetramorium sericeiventre Emery and Pheidole sp., and the lacewing Mallada sp. were recorded as predators of M. ochroptera for the …

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The Nature Of The Gregarizing Signal Responsible For Maternal Transfer Of Phase To The Offspring In The Desert Locust Schistocerca Gregaria, Atem G. Malual, Ahmed Hassanali, Baldwyn Torto, Yousif O.H. Assad, Peter G.N. Njagi Aug 2001

The Nature Of The Gregarizing Signal Responsible For Maternal Transfer Of Phase To The Offspring In The Desert Locust Schistocerca Gregaria, Atem G. Malual, Ahmed Hassanali, Baldwyn Torto, Yousif O.H. Assad, Peter G.N. Njagi

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We examined aggregative behavior of hatchlings of the desert locust Schistocerca gregaria emerging from solitaria egg pods that had been incubated in sand previously used for consecutive ovipositions by gregarious females. Hatchlings derived from such eggs were significantly more gregarious than those derived from pods laid in clean sand. The gregarizing effect of the sand-associated factor originating from 3, 5, or 10 ovipositions by gregarious females increased in a dose-dependent fashion. Washing the sand with organic solvents following such ovipositions, or flushing it with nitrogen gas, led to substantial loss of its gregarizing effect, showing that the active signal is …

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Blend Effects In The Toxicity Of The Essential Oil Constituents Of Ocimum Kilimandscharicum And Ocimum Kenyense (Labiateae) On Two Post-Harvest Insect Pests, Jembere Bekele, Ahmed Hassanali Jun 2001

Blend Effects In The Toxicity Of The Essential Oil Constituents Of Ocimum Kilimandscharicum And Ocimum Kenyense (Labiateae) On Two Post-Harvest Insect Pests, Jembere Bekele, Ahmed Hassanali

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The lethal toxicity of major components of the essential oils of Ocimum kilimandscharicum and O. kenyense and of selected blends of these against Sitophilus zeamais and Rhyzopertha dominica were compared with those of the full blends of the essential oils. The compounds were assayed in amounts and proportions present in the minimum 100% lethal dose of the oils. Whereas a major component of O. kilimandscharicum was found to be largely responsible for the toxic action of its essential oil against R. dominica, the results with the other treatments indicated that the toxic action of the essential oils were due to …

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Polymorphism For Wolbachia Infections In Eastern And Southern African Cotesia Sesamiae (Cameron) (Hymenoptera: Braconidae) Populations, Adele J. Ngi-Song, Moses B. Mochiah Jan 2001

Polymorphism For Wolbachia Infections In Eastern And Southern African Cotesia Sesamiae (Cameron) (Hymenoptera: Braconidae) Populations, Adele J. Ngi-Song, Moses B. Mochiah

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Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) is an indigenous, gregarious, larval endo/parasitoid which is widely distributed in Africa and attacks mid- to late instars of stemborers. There is renewed interest in using Co. sesamiae for biological control to reduce the problems caused by stemborers. However, Wolbachia sp., a bacterial symbiont of some populations of Co. sesamiae, poses some threat to the successful use of the parasitoid for stemborer control. This bacterium's common effect is cytoplasmic incompatibility, between infected males and uninfected females. Polymerase chain reaction (PCR) tests were carried out on parasitoid samples collected from 5 locations in Kenya and 8 …

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