Research Papers/Topics in Entomology

Diversity and Abundance of Wild host Plants of Lepidopteran Stem borers in two Agro-ecological zones of Kenya

Abstract: A survey was carried out between 2005 and 2006 in two ecologically different localities, Suam and Mtito Andei, to assess diversity and abundance of wild host plants of lepidopteran stem borers during the cropping and non-cropping seasons. Suam in western Kenya is situated in the moist high tropics and is characterised by an Afromontane vegetation mosaic, while Mtito Andei is located in the dry mid-altitudes characterised by a Somalia Masai vegetation mosaic. In Suam, wild host plan...

Scope for Genetic Enhancement of the Parasitisation Potential of Four Native Strains of Trichogrammatoidea sp. nr. lutea Girault (Hymenoptera: Trichogrammatidae) in Kenya

Abstract: In response to emerging interest in commercial mass production of Trichogramma for Helicoverpa armigera biocontrol in eastern Africa, laboratory experiments were undertaken to assess the scope for genetic enhancement of the parasitisation potential of native strains of the local common trichogrammatid species, Trichogrammatoidea sp. nr. lutea . Four promising strains (ex-Kilifi Kilifi District, ex-Kwa Chai Kibwezi District, ex-Rarieda Bondo District and ex-Ebuhayi, Kakamega Distric...

Life History Parameters of Ceratitis capitata (Diptera: Tephritidae) Reared on Liquid Diets

Abstract: A liquid diet for rearing Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) was developed. Several yeast-based products were evaluated as diet ingredients, and a combination of whole cell yeast (LBI2240) and hydrolyzed yeast (such as FNILS65) in 1:1Ð3:1 ratio was selected for use in the study. Larvae reared in a liquid diet with LBI2240:FNILS65 ratios of either 1:1 or 3:1 resulted in the same pupal recovery as to those reared in the conventional mill fee- based control diet. L...

Inheritance of ‘Domestication’ Traits in Bambara Groundnut (Vigna subterranea (L.) Verdc.)

Abstract: Controlled crosses in bambara groundnut were attempted between a range of thirty-six bambara groundnut landraces (thirty domesticated (V. subterranea var. subterranea) and six wild (V. subterranea var. spontanea)). Ten F1 seed were produced. Of these, eight germinated producing F2 populations. On seed set, four populations could be unambiguously confirmed as true crosses by F3 seed coat colour. A single F2 population, derived from a domesticated landrace from Botswana (DipC; female...

Host Plants and Host Plant Preference Studies for Bactrocera invadens (Diptera: Tephritidae) in Kenya, a New Invasive Fruit Fly Species in Africa

Abstract: Bactrocera invadens Drew, Tsuruta & White (Diptera: Tephritidae), an invasive fruit ßy species of Asian origin, was detected in Kenya in 2003, and is now well established in several parts of the country. We assessed the host range of this major quarantine pest in Kenya by collecting a wide range of cultivated and wild host plants from December 2004 to April 2006. Fruit were collected from 90 plant species representing 40 families from the Coast, Eastern, and Rift Valley provinces ...

Development and reproductive potential of diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) on cultivated and wild crucifer species in Kenya

Abstract: The development, survival and reproductive potential of diamondback moth Plutella xylostella (Linnaeus) were studied at 25 ^ 1 8C in the laboratory in response to two cultivated Brassica oleracea cultivars (cabbage B. oleracea var. capitata and kale B. oleracea var.acephala) and four wild crucifer species Erucastrum arabicum, Raphanus raphanistrum,Rorippa nudiuscula and Rorippa micrantha. Rorippa micrantha was the most preferred species in oviposition choice tests, while cabbage an...

Life History of the Predatory Mite Phytoseiulus fragariae on Tetranychus evansi and Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) at Five Temperatures

Abstract: Tetranychus evansi Baker and Pritchard and Tetranychus urticae Koch (Acari: Tetranychidae) are important pests of Solanaceae in many countries. Several studies have demonstrated that T. urticae is an acceptable prey to many predatory mites, although the suitability of this prey depends on the host plant. T. evansi, has been shown to be an unfavorable prey to most predatory mites that have been tested against it. The predator Phytoseiulus fragariae Denmark and Schicha (Acari: Phytos...

Ecological niche and potential geographic distribution of the invasive fruit fly Bactrocera invadens (Diptera, Tephritidae)

Abstract: Two correlative approaches to the challenge of ecological niche modeling (genetic algorithm, maximum entropy) were used to estimate the potential global distribution of the invasive fruit fly, Bactrocera invadens, based on associations between known occurrence records and a set of environmental predictor variables. The two models yielded similar estimates, largely corresponding to Equatorial climate classes with high levels of precipitation. The maximum entropy approach was somewha...

Side-effects of Pesticides on the Life Cycle of the Mite Pathogenic Fungus Neozygites Xoridana

Abstract: The tomato red spider mite, Tetranychus evansi Baker and Pritchard, is an invasive species in Africa causing considerable damage to Solanaceous crops. The fungal pathogen Neozygites Xoridana Weiser and Muma from Brazil has been considered a potential candidate for introduction into Africa for the control of T. evansi. To be incorporated in the tomato production system, N. Xoridana has to be compatible with the pesticides used for the control of other pests and diseases. Pesticides ...

Interspecific Competition Between Diadegma Semiclausum Hellen and Diadegma mollipla (Holmgren), Parasitoids of the Diamondback Moth, Plutella Xylostella (L), Feeding on a New Host Plant

Abstract: Interspecific competition between an introduced parasitoid species aimed at controlling a herbivorous pest species and a native parasitoid parasitising the same host may influence the success of classical biological control programmes. In Kenya, interspecific competition between an introduced and a local parasitoid on two diamondback moth populations (DBM, Plutella xylostella) was investigated on two different host plants. We tested simultaneous and delayed competition of the local...

Isolation and characterization of microsatellite markers in the newly discovered invasive fruit fly pest in Africa, Bactrocera invadens (Diptera: Tephritidae)

Abstract: We describe the isolation and characterization of 11 polymorphic microsatellite loci from the recently discovered fruit fly pest, Bactrocera invadens. The polymorphism of these loci was tested in individual flies from two natural populations (Sri Lanka and Democratic Republic of Congo). Allele number per locus ranged from three to 15 and eight loci displayed a polymorphic information content greater than 0.5. These microsatellite loci provide useful markers for studies of populatio...

Effect of Temperature on Development and Survival of Immature Stages of Bactrocera invadens (Diptera: Tephritidae)

Abstract: The development and survival of immature stages of Bactrocera invadens Drew, Tsuruta and White (Dipt.: Tephritidae), a new invasive fruit fly pest in Africa, was studied in the laboratory at five constant temperatures of 15 C, 20 C, 25 C, 30 C and 35 C and photoperiod of L12:D12. The developmental time of eggs was 5.71 days at 15 C, decreasing to 1.24 days at 35 C. Larval development periods decreased from 35.95 days at 15 C to 6.64 days at 35 C. Pupal development at 15 C took 34.0...

Management of Helicoverpa armigera (Lepidoptera: Noctuidae) by nutritional indices study and botanical extracts of Millettia ferruginea and Azadirachta indica

Abstract: The development of hosts that are resistant and evaluation of botanical extracts to H. armigera Hübner (Lepidoptera: Noctuidae) is crucial for sustainable management, yet very limited in Ethiopia. Therefore, this study was done to identify alternative methods to insecticide control through host consumption study and botanical extracts. The performance of third-fifth larval stages of H. armigera on three host plant varieties including chickpea, tomato and faba bean and botanical ex...

Attraction response of adult Rhipicephalus appendiculatus and Rhipicephalus pulchellus (Acari: Ixodidae) ticks to extracts from Calpurnia aurea (Fabaceae)

Abstract: Experiments were carried out to investigate the response of two tick species Rhipicephalus pulchellus Gerstaker, 1873 and Rhipicephalus appendiculatus Neumann, 1901 to three different extracts (acetone, aqueous and oil) of the dried leaves of Calpurnia aurea (Aiton)Benth in both an inverted glass tube and a dual choice T-olfactometer. The oil extract at 50 and 100 mg/ml attracted 46.7% and 65.9% of R. appendiculatus, respectively, in the inverted glass tube assay, which was compara...

On the Occurrence of Bistrispinaria, Grass-breeding Fruit Flies (Diptera: Tephritidae) in Kenya, with an Addition to the Tephritid Checklist of Kakamega Forest.

Abstract: Identification of specimens from Malaise trap collections and rearings of tephritids from native and cereal grasses confirm the presence in Kenya of Bistrispinaria magniceps, B. fortis, and B. woodi, of which the latter two species are recorded for the first time. Including an earlier, but uncertain, record of B. atlas, all four species of Bistrispinaria, the only genus of Tephritidae in the Afrotropical region known to breed in grass stems, have now been recorded from Kenya. Infor...


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