Diversity, distribution and role of wild crucifers in major cabbage and kale growing areas of Kenya
Creators: name: Kahuthia-Gathu, R.
name: Löhr, B.
name: Poehling, Hans-Michael
name: Mbugua, P.K.
Publisher: name: Cambridge : Cambridge University Press
Year: 2009
Subjects: subject: Agro-ecological systems
subject: Conservation biological control
subject: Cruciferous weeds
subject: Diamondback moth
subject: Parasitoids
subject: Recolonization
subject: Species diversity
subject: dominance
subject: host plant
subject: leafy vegetable
subject: local extinction
subject: moth
subject: pesticide application
subject: recolonization
subject: semiarid region
subject: spatial distribution
subject: species diversity
subject: species evenness
subject: species richness
subject: upland region
subject: wild population
subject: Africa
subject: East Africa
subject: Kenya
subject: Sub-Saharan Africa
subject: Apanteles sp.
subject: Brachymeria
subject: Brassica
subject: Brassica juncea
subject: Brassica oleracea var. capitata
subject: Brassica rapa
subject: Brassica rapa subsp. rapa
subject: Capsella bursa-pastoris
subject: Coronopus didymus
subject: Cotesia plutellae
subject: Crambe kilimandscharica
subject: Diadegma semiclausum
subject: Erucastrum
subject: Lepidium
subject: Lepidium bonariense
subject: Lepidoptera
subject: Nasturtium officinale
subject: Oomyzus sokolowskii
subject: Plutellidae
subject: Raphanus raphanistrum
subject: Raphanus sativus
subject: Rorippa nudiuscula
subject: Sisymbrium officinale
subject: altitude
subject: analysis of variance
subject: animal
subject: article
subject: biodiversity
subject: Brassicaceae
subject: demography
subject: ecosystem
subject: host parasite interaction
subject: parasitology
subject: physiology
subject: season
subject: species difference
subject: Altitude
subject: Analysis of Variance
subject: Animals
subject: Biodiversity
subject: Demography
subject: FOS: Sociology
subject: Ecosystem
subject: Host-Parasite Interactions
subject: Moths
subject: Seasons
subject: Species Specificity
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: An investigation of the diversity and distribution of wild crucifer species and their importance for cultivated crucifers was conducted during 2005 and 2006 in the highland and mid-altitude semi-arid areas of Kenya. Thirteen species of wild crucifers in nine genera were recorded: Raphanus raphanistrum, Erucastrum arabicum, Sisymbrium officinale, Crambe kilimandscharica, Capsella bursa-pastoris, Rorippa nudiuscula, Ro. micrantha, Ro. microphylla, Lepidium bonariense, Coronopus didymus, Brassica rapa, B. juncea and an unidentified Brassica species. Highland areas had significantly higher species diversity and species richness than mid-altitude semi-arid areas. Species richness, diversity and evenness varied with season and location. Raphanus raphanistrum was the dominant non-cultivated species in the highlands followed by E. arabicum, which was also present and dominant in the semi-arid study sites. Diamondback moth (DBM) was recorded from ten wild crucifer species and R. raphanistrum and E. arabicum were the preferred host plant species. Overall, four larval, one larval-pupal and one pupal parasitoid of DBM were recorded: Diadegma semiclausum, D. mollipla, Apanteles sp., Cotesia plutellae, Oomyzus sokolowskii and Brachymeria species, respectively. Diadegma semiclausum was the most dominant species on all crucifers. We conclude that wild crucifers act as alternative hosts for DBM and provide refugia for DBM parasitoids, which risk local extinction through pesticide application or competition from introduced exotic parasitoid species. The wild crucifers also act as recolonization sites for DBM parasitoids.