Open Access. Powered by Scholars. Published by Universities.®

Beef Science Commons™

Open Access. Powered by Scholars. Published by Universities.®

Entomology

Articles 31 - 50 of 50

Full-Text Articles in Beef Science

Eco-Social Analysis Of An East African Agro-Pastoral System: Management Of Tsetse And Bovine Trypanosomiasis, Johann Baumgärtner, Gianni Gilioli, Getachew Tikubet, Andrew Paul Gutierrez Mar 2008

Eco-Social Analysis Of An East African Agro-Pastoral System: Management Of Tsetse And Bovine Trypanosomiasis, Johann Baumgärtner, Gianni Gilioli, Getachew Tikubet, Andrew Paul Gutierrez

All Peer-Reviewed Publications

A key constraint for development of many East African agro-pastoral communities is African animal trypanosomiasis or nagana caused by Trypanosoma spp. and vectored by species of tsetse flies (Glossina spp.). Suppression of trypanosomiasis through trapping of tsetse fly populations was conducted from 1995 to 2005 at and near Luke, Southwest Ethiopia. Odor baited mass trapping technology was used to suppress adult fly populations to very low levels while tryponocidal drugs were used to treat trypanosome infections in cattle. Data on ecological, economic and social variables were collected and analyzed in the context of eco-social dynamics in the community. The bio-economic …

Go to article

Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini Jun 2007

Livestock Farmers' Perception And Epidemiology Of Bovine Trypanosomosis In Kwale District, Kenya, S. O. Ohaga, E. D. Kokwaro, I. O. Ndiege, A. Hassanali, R. K. Saini

All Peer-Reviewed Publications

We did cross-sectional surveys in Kwale District, Kenya to determine the epidemiology of bovine trypanosomosis and livestock owners' perceptions of the disease. The surveys involved relative importance of trypanosomosis, examination of the current disease constraints, current control practices and drug-use patterns. Informal meetings were held with farmers and cattle census undertaken. Tsetse-fly densities and trypanosomosis prevalences in cattle were determined. A total of 132 farmers were interviewed. Trypanosomosis, anaplasmosis, East Coast fever, foot-and-mouth diseases were reported to be the major constraints to livestock production. Trypanosomosis was the most important compared to other diseases. Chemotherapy was the most widely used method …

Go to article

Combined Control Of Striga Hermonthica And Stemborers By Maize-Desmodium Spp. Intercrops, Zeyaur R. Khan, John A. Pickett, Lester J. Wadhams, Ahmed Hassanali, Charles A.O. Midega Sep 2006

Combined Control Of Striga Hermonthica And Stemborers By Maize-Desmodium Spp. Intercrops, Zeyaur R. Khan, John A. Pickett, Lester J. Wadhams, Ahmed Hassanali, Charles A.O. Midega

All Peer-Reviewed Publications

The African witchweed (Striga spp.) and lepidopteran stemborers are two major biotic constraints to the efficient production of maize in sub-Saharan Africa. Previous studies had shown the value of intercropping maize with Desmodium uncinatum in the control of both pests. The current study was conducted to assess the potential role of other Desmodium spp., adapted to different agro-ecologies, in combined control of both pests in Kenya. Treatments consisted of intercropped plots of a Striga hermonthica- and stemborer-susceptible maize variety and one Desmodium sp. or cowpea, with a maize monocrop plot included as a control. S. hermonthica counts and stemborer damage …

Go to article

Relationships Of Intercropped Maize, Stem Borer Damage To Maize Yield And Land-Use Efficiency In The Humid Forest Of Cameroon, A. Chabi-Olaye, C. Nolte, F. Schulthess, C. Borgemeister Oct 2005

Relationships Of Intercropped Maize, Stem Borer Damage To Maize Yield And Land-Use Efficiency In The Humid Forest Of Cameroon, A. Chabi-Olaye, C. Nolte, F. Schulthess, C. Borgemeister

All Peer-Reviewed Publications

Stem borers are the most important maize pests in the humid forest zone of Cameroon. Field trials were conducted in the long and short rainy seasons of 2002 and 2003 to assess the level of damage and yield reductions caused by stem borers in monocropped maize and in maize intercropped with non-host plants such as cassava, cowpea and soybean. The intercrops were planted in two spatial arrangements, i.e. alternating hills or alternating rows. All intercrops and the maize monocrop were grown with and without insecticide treatment for assessment of maize yield loss due to borer attacks. The land-use efficiency of …

Go to article

Integrated Arthropod Pest Management Systems For Human Health Improvement In Africa, Johann Baumgärtner, Fritz Schulthess, Yunlong Xia Jan 2003

Integrated Arthropod Pest Management Systems For Human Health Improvement In Africa, Johann Baumgärtner, Fritz Schulthess, Yunlong Xia

All Peer-Reviewed Publications

In a sub-Saharan African context, limited natural resources, infectious diseases, including those transmitted by arthropod vectors, and chronic exposure to food contaminated with mycotoxin-producing fungi which, among others, are vectored by insects, are among the major constraints to human health. Thus, pest control should be an important component in human health improvement projects. It appears that the advantages of preventive over curative methods are rarely recognised in Africa, with more emphasis being given to the search for the 'silver bullet' than to integrated control approaches. Integrated pest management (IPM) systems can be assigned to different decision-making levels as well as …

Go to article

Pathogenicity And Antifeedant Activity Of Entomopathogenic Hyphomycetes To The Cowpea Leaf Beetle, Ootheca Mutabilis Shalberg, S. Ekesi Jan 2001

Pathogenicity And Antifeedant Activity Of Entomopathogenic Hyphomycetes To The Cowpea Leaf Beetle, Ootheca Mutabilis Shalberg, S. Ekesi

All Peer-Reviewed Publications

Conidial suspensions of four isolates each of Bcauvcria bassiana and Melnrhizhtm anisopliae were evaluated in the laboratory for their virulence to adult Ootlicca mntabilis. All the isolates tested were pathogenic to the beetle, but to varying degrees. Three of them, B. bassiana CPD 3 and CPD10 and M. anisopliae CPD 6 were superior to all other isolates in terms of mortality induced on adult beetle, LT50 and LC50, with B. bnssiana CPD 3 having the lowest LC50 value. In feeding assayi consumption by beetles treated with B. bnssiana CPD 3 was significantly reduced within 2 days treatment (DAT) and the …

Go to article

Cattle And Amblyomma Variegatum Odors Used In Host Habitat And Host Finding By The Tick Parasitoid, Ixodiphagus Hookeri, Fanuel A. Demas, Ahmed Hassanali, Esther N. Mwangi, Edna C. Kunjeku, Audrey R. Mabveni Jan 2000

Cattle And Amblyomma Variegatum Odors Used In Host Habitat And Host Finding By The Tick Parasitoid, Ixodiphagus Hookeri, Fanuel A. Demas, Ahmed Hassanali, Esther N. Mwangi, Edna C. Kunjeku, Audrey R. Mabveni

All Peer-Reviewed Publications

The response of mated naive Ixodiphagus hookeri females to cattle and Amblyomma variegatum nymphal odors was tested in a Y-tube olfactometer. I. hookeri females were attracted to cattle urine, dung, and odors from tick- free feeding sites of A. variegatum nymphs on cattle, e.g., dewlaps, front heels, and hind heels. Tick-free scrotal odors did not attract the parasitoids. Furthermore, odors from off-host unfed and fed A. variegatum nymphs did not attract the parasitoids, despite an increase in the number of the nymphs to amplify any odor signal. A blend of odors from feeding on-host nymphs and cattle scrota attracted the …

Go to article

Susceptibility Of The Legume Flower Thrips To Metarhizium Anisopliae On Different Varieties Of Cowpea, S. Ekesi, N. K. Maniania, W. Lwande Jan 2000

Susceptibility Of The Legume Flower Thrips To Metarhizium Anisopliae On Different Varieties Of Cowpea, S. Ekesi, N. K. Maniania, W. Lwande

All Peer-Reviewed Publications

The susceptibility of Megalurothrips sjostedti to Metarhizium anisopliae when reared on susceptible, tolerant, and moderately resistant varieties of cowpea at different constant temperatures was evaluated in the laboratory. Insects were exposed either to direct spray of the conidia or to fungus-treated floral tissues. Mortality was significantly higher on the moderately resistant variety at all temperatures compared to the susceptible and tolerant varieties. Correspondingly, lethal time and lethal concentration values were significantly shorter and lower, respectively, on the moderately resistant variety compared to the other varieties, thus indicating that the two control methods are compatible as part of an integrated pest …

Go to article

Selection Of Virulent Isolates Of Entomopathogenic Hyphomycetes Against Clavigralla Tomentosicollis Stål. And Evaluation In Cage Experiment Using Three Cowpea Varieties, S. Ekesi Dec 1999

Selection Of Virulent Isolates Of Entomopathogenic Hyphomycetes Against Clavigralla Tomentosicollis Stål. And Evaluation In Cage Experiment Using Three Cowpea Varieties, S. Ekesi

All Peer-Reviewed Publications

The virulence of 8 isolates of entomopathogenic hyphomycetes against adult and 5th instar nymph of Clavigralla tomentosicollis was evaluated in the laboratory at 4 different concentrations of inoculum. At all concentrations, Beauveria bassiana CPD 9 and Metarhizium anisopliae CPD 5 caused the highest mortality in adult bug ranging from 58 to 97% and 53 to 100%, respectively at 7 days post inoculation. The same isolates had the shortest LT50 (3.5 and 4.1 days, respectively) and the lowest LC50 (1.8 × 105 and 9.8 × 104 conidia ml-1) values in adult insects. In nymphs, M. anisopliae CPD 5 was the most …

Go to article

Cleome Hirta Essential Oil As Livestock Tick (Rhipicephalus Appendiculatus) And Maize Weevil (Sitophilus Zeamais) Repellent, M. W. Ndungu, S. C. Chhabra, W. Lwande Oct 1999

Cleome Hirta Essential Oil As Livestock Tick (Rhipicephalus Appendiculatus) And Maize Weevil (Sitophilus Zeamais) Repellent, M. W. Ndungu, S. C. Chhabra, W. Lwande

All Peer-Reviewed Publications

The repellency of the essential oil of the shrub Cleome hirta and of three identified constituents (phytol, (+)-cedrol, n-octacosane) was evaluated against the livestock tick, Rhipicephalus appendiculatus and the maize weevil, Sitophillus zeamais. In a tick climbing repellency bioassay, the oil exhibited repellency which, at the highest dose, was comparable to that of the commercial arthropod repellent N,N-diethyltoluamide (DEET). In a Y-tube olfactometer bioassay, the oil showed higher or comparable repellency against S. zeamais relative to DEET at all the doses tested. The potential of C. hirta in livestock tick and maize weevil control is discussed. Copyright (C) 1999 Elsevier …

Go to article

Trypanosome Infection Rate In Cattle At Nguruman, Kenya, R. A. Tarimo-Nesbitt, T. K. Golder, R. D. Dransfield, M. F. Chaudhury, R. Brightwell Feb 1999

Trypanosome Infection Rate In Cattle At Nguruman, Kenya, R. A. Tarimo-Nesbitt, T. K. Golder, R. D. Dransfield, M. F. Chaudhury, R. Brightwell

All Peer-Reviewed Publications

Trypanosome infection rate in cattle at Nguruman was investigated in a study conducted in 1984-1986. Shifting pastoralism significantly reduced trypanosome infections in cattle. The cattle were more heavily infected with Trypanosoma congolense (16.5%) than Trypanosoma vivax (4.95%) and Trypanosoma brucei (0.19%). Trypanosoma theileri was observed only once among the cattle examined. Mixed trypanosome infections in cattle were observed to be 2.75% and 0.014% for T. congolense/T. vivax and T. congolense/T. brucei, respectively. The duration of infection in the cattle was 55 days for T. congolense and 79 days for T. vivax. High infections in cattle were observed 2 months after …

Go to article

Potential Of The Entomopathogenic Fungus, Metarhizium Anisopliae (Metsch.) Sorokin For Control Of The Legume Flower Thrips, Megalurothrips Sjostedti (Trybom) On Cowpea In Kenya, S. Ekesi, N. K. Maniania, K. Ampong-Nyarko, I. Onu Nov 1998

Potential Of The Entomopathogenic Fungus, Metarhizium Anisopliae (Metsch.) Sorokin For Control Of The Legume Flower Thrips, Megalurothrips Sjostedti (Trybom) On Cowpea In Kenya, S. Ekesi, N. K. Maniania, K. Ampong-Nyarko, I. Onu

All Peer-Reviewed Publications

Field experiments were conducted at Mbita, western Kenya for two seasons to evaluate the potential of the entomopathogenic fungus, Metarhizium anisopliae (Metsh.) Sorokin, for biological control of the legume flower thrips, Megalurothrips sjostedti (Trybom), on cowpea. An ultra-low-volume (ULV) oil/aqueous formulation and a high-volume (HV) aqueous formulation of conidia were applied three times each at two concentrations of 1 x 1011 and 1 x 1013 conidia ha-1. Compared with the untreated controls, both formulations significantly reduced thrips populations and plant damage in both seasons. Adult insects collected from fungal-treated plots and reared in the laboratory showed a high mortality due …

Go to article

Neem Seed Extract Spray Applications As Low-Cost Inputs For Management Of The Flower Thrips In The Cowpea Crop, R. C. Saxena, E. L. Kidiavai Jan 1997

Neem Seed Extract Spray Applications As Low-Cost Inputs For Management Of The Flower Thrips In The Cowpea Crop, R. C. Saxena, E. L. Kidiavai

All Peer-Reviewed Publications

In field trials conducted at the Experiment Station and in a farmer's field at Mbita near the shores of Lake Victoria, Kenya, applications of 2% or 3% neem seed extract (NSE) @ 200 l/ha with a knapsack sprayer at 38, 47 and 51 days after emergence (DE) of the cowpea crop or 5%, 10% or 20% NSE sprayed @ 10 l/ha with an ultra-low-volume applicator at 31, 39 and 49 DE often significantly reduced the number of larvae of the flower thrips, Megalurothrips sjostedti (Trybom), in cowpea flowers recorded 2 days after each treatment. Also fewer adults occurred in flowers …

Go to article

Genetics Of Resistance To Aphis Craccivora In Cowpea, S. M. Githiri, K. Ampong-Nyarko, E. O. Osir, P. M. Kimani Jan 1996

Genetics Of Resistance To Aphis Craccivora In Cowpea, S. M. Githiri, K. Ampong-Nyarko, E. O. Osir, P. M. Kimani

All Peer-Reviewed Publications

Inheritance of aphid resistance and allelic relationships among sources of resistance was studied in the parents, F1, F2, F3, and backcross populations of cowpea crosses. Each 4-day old seedling was infested with five fourth-instar aphids. Seedling reaction was recorded 14-16 days after infestation when the susceptible check was killed. The segregation data from eight crosses between resistant and susceptible cowpea cultivars indicated that aphid resistance was inherited as a monogenic dominant trait. Segregation data from crosses among eight resistant cultivars indicated that one or two loci and modifier(s) were involved in the expression of resistance to aphids. It was suggested …

Go to article

Reproductive Performance And Population Dynamics Of Cowpea Aphid (Homoptera: Aphididae) On Leaf Extracts Of Resistant And Susceptible Cowpeas, I. Billy Annan, Ward M. Tingey, George A. Schaefers, Kailash N. Saxena Jan 1996

Reproductive Performance And Population Dynamics Of Cowpea Aphid (Homoptera: Aphididae) On Leaf Extracts Of Resistant And Susceptible Cowpeas, I. Billy Annan, Ward M. Tingey, George A. Schaefers, Kailash N. Saxena

All Peer-Reviewed Publications

Membrane feeding studies were conducted to determine the effects of raw juices and chemical extracts of leaves of aphid-resistant (ICV-12) and aphid- susceptible (ICV-1) cultivars of cowpea [Vigna unguiculata L. (Walp.)], on the survival, growth, and reproduction of cowpea aphid Aphis craccivora Koch. Life table and demographic statistics of the cohort population and subsequent generations were estimated. Compared to ICV-1, the leaf juices and chemical extracts of ICV-12 exhibited significant (P ≤ 0.05) adverse effects on aphid survival, growth, and reproduction. Raw leaf juice and ethyl acetate extract of ICV-12 in both water and sucrose significantly (P ≤ 0.05) limited …

Go to article

Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe Jan 1995

Effect Of Pubescence In Cowpea Resistance To The Legume Pod Borer Maruca Testulalis (Lepidoptera: Pyralidae), S. Oghiakhe

All Peer-Reviewed Publications

Pubescence (trichomes) in wild and cultivated cowpeas, Vigna vexillata and V. unguiculata, adversely affected oviposition, mobility, and food consumption and utilisation by the legume pod borer, Maruca testulalis (Geyer), in tests conducted with TVnu 72 (wild, highly resistant and highly pubescent), TVu 946 (semi-wild, moderately resistant and pubescent) and IT82D-716 (cultivated, highly susceptible and pubescent). In free-choice and no-choice tests, significantly (P < 0.05) fewer eggs were laid on 3-week-old potted plants of TVnu 72, the highly pubescent and wild species; this species also received fewer eggs on abaxial and adaxial leaf surfaces. Ovipositional activity on stipules, stem, branches, terminal shoots, adaxial and abaxial leaf surfaces of the susceptible cultivar, IT82D-716 was higher (P < 0.05) than on TVu 946 and TVnu 72. More eggs were laid on the abaxial surfaces than on the adaxial surfaces of leaves for all tests conducted, except for the TVnu 72 no-choice test. Significant negative correlations (r = -0.99** and r = -0.99**) were found between mean number of eggs laid and length and density of non-glandular trichomes. There was a significant negative correlation (r = -0.99**) between larval velocity and length of non-glandular trichomes on pod surface. Similarly, significant negative correlations (r = -0.85* and -0.89*) were found between larval velocity and density and length of non-glandular trichomes on leaf surface. Pods of IT82D-716 and TVnu 72 were the most - and least - preferred for settling by larvae of M. testulalis, respectively. There was a significant positive correlation (r = 0.99**) between larval penetration time on pods and length of non-glandular trichomes. Weight loss, number of feeding punctures and number of larvae on whole pods of TVnu 72 were lower and significantly different (P < 0.05) from IT82D-716 and TVu 946. This study showed that it would be advantageous to use TVnu 72 in a breeding programme to incorporate pubescence into high-yielding commercial cultivars for resistance against M. testulalis and possibly other major pests. © 1995.

Go to article

Detection Of Trypanosome Infections In The Saliva Of Tsetse Flies And Buffy-Coat Samples From Antigenaemic But Aparasitaemic Cattle, P. A.O. Majiwa, R. Thatthi, S. K. Moloo, J. H.P. Nyeko Jan 1994

Detection Of Trypanosome Infections In The Saliva Of Tsetse Flies And Buffy-Coat Samples From Antigenaemic But Aparasitaemic Cattle, P. A.O. Majiwa, R. Thatthi, S. K. Moloo, J. H.P. Nyeko

All Peer-Reviewed Publications

Relatively simple protocols employing non-radioactive DNA probes have been used for the detection of African trypano-somes in the blood of mammalian hosts and the saliva of live tsetse flies. In combination with the polymerase chain reaction (PCR), the protocols revealed trypanosomes in buffy-coat samples from antigenaemic but aparasitaemic cattle and in the saliva of live, infected tsetse flies. Furthermore, the protocols were used to demonstrate concurrent natural infections of single tsetse flies with different species of African trypanosomes. © 1994, Cambridge University Press. All rights reserved.

Go to article

Trypanosome Infection Rates In Tsetse Flies (Diptera: Glossinidae) And Cattle During Tsetse Control Operations In The Kagera River Region Of Rwanda, Steve Mihok, Leonard H. Otieno, Christopher S. Tarimo Jan 1992

Trypanosome Infection Rates In Tsetse Flies (Diptera: Glossinidae) And Cattle During Tsetse Control Operations In The Kagera River Region Of Rwanda, Steve Mihok, Leonard H. Otieno, Christopher S. Tarimo

All Peer-Reviewed Publications

Trypanosome infections were monitored in three species of tsetse fly (Glossina pallidipes Austen, G. morsitans centralis Machado, and G. brevipalpis News-tead) at four locations in the Kagera River region of Rwanda from May 1989 to September 1990. Two of the four areas (Mpanga Ranch and Bukora Ranch) were subjected to tsetse fly suppression operations with odour-baited traps. Proboscis infections of the Trypanosoma congolense and T. vivax types accounted for roughly equal numbers of the 207 mature infections detected (3.8%). Variation in infection rates was area-specific rather than tsetse species-specific. Order of magnitude differences in tsetse fly densities among areas were …

Go to article

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

All Peer-Reviewed Publications

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 …

Go to article

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

All Peer-Reviewed Publications

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 …

Go to article

First Prev