Arthropod pests and their natural enemies in stored crops in northern Namibia

Abstract

A survey of stored product pests, their natural enemies, grain storage and pest management approaches in northern Namibia was conducted. The survey revealed five types of crop commodities (pearl millet, sorghum, cowpea, maize, feed mixture) stored in four types of grain stores (baskets, bag stags-flat stores, concrete bin, metal containers). No synthetic pesticides or plastic sheeting was recorded. Wooden-ash natural pesticide is the only protectant used. Ten insect pest species were found affiliated to the orders of Coleoptera (Attagenus fasciatus, Callosobruchus subinnotatus, Cryptolestes ferrugineus, Oryzaephilus surinamensis, Rhyzopertha dominica and Tribolium castaneum), Lepidoptera (Corcyra cephalonica, Sitotroga cerealella), Psocoptera (Liposcelis paeta) and Blattodea (Blattella germanica). Out of these, seven species were recognized as new stored-products pests for Namibia. Although listed for southern Africa region, no storage pest-mites (Acari) and Sitophilus spp., Prostephanus sp. or Trogoderma sp. beetles were traced. We found four new species of natural enemies of storage pests recruiting from insects (Habrobracon hebetor, Cephalonomia wattersoni, Brachymeria sp.) and mites (Blattisocius tarsalis). The occurrence of natural enemies indicates a potential for pest bio-control in Namibian grain stores.

Participatory appraisal of production constraints, preferred traits and farming system of cowpea in the northern Namibia: implications for breeding

“…Other authors reported losses of 70% quality after Callosobruchus attack (Murdock et al, 2003;Stejskal et al, 2006). Studies on indigenous knowledge practice on pests of stored crops in the Northern Namibia established that farmers mix cowpea seeds with ash and store grains in sealed clay pots, calabash or any possible container to prevent insects from hatching (Stejskal et al, 2006).…”

“…Fleissner and Bagnall-Oakeley (2001) reported that only 5,000 tonnes of cowpea were produced annually by the Namibian communal farming households. Furthermore, the reported cowpea yields vary from 250 to 350 kg/ha -1 per household, which is relatively low compared to the yield potential of 1500 to 3000 kg/ha -1 (Stejskal et al, 2006). In the country only three cowpea varieties were made available to growers during 1997 (Fleissner and Bagnall-Oakeley, 2001).…”

“…This approach considers the value of stakeholders' knowledge, their preferences, abilities and innovation (Chandra and Sharma, 2010). In Namibia, there is no recent participatory research documentation on the production status, farmers' production constraints or varietal preferences among the major cowpea growing ago-ecologies (Matanyaire, 1996;Fleissner and Bagnall-Oakeley, 2001;Stejskal et al, 2006). Therefore, the objective of this study was to assess farmers'-perceived production constraints, preferred traits, the farming system of cowpea, and their combined implications for breeding cowpea for northern Namibia.…”

Overview of present and past and pest-associated risks in stored food and feed products: European perspective

“…This is likely due to the fact that stored product mites are neither common nor diverse pests in subtropical and tropical countries (e.g. Stejskal et al, 2006) that are the main pool-source for invasive pests. Although there are no new species, there are emerging issues e especially for minor pests e concerning species composition and frequencies in stored grain communities in Europe.…”

Review of Parasitoid Wasps and Flies (Hymenoptera, Diptera) Associated with Limacodidae (Lepidoptera) in North America, with a Key to Genera

“…can occur in various environments: as Brachymeria vesparum Bou ek (Hymenoptera: Chalcididae) parasitizing Polistes lanio lanio F. (Hymenoptera: Vespidae) larvae in Rio de Janeiro, Brazil (Silva-Filho et al 2007) and Brachymeria sp. parasitizing larvae of stored grain pests in Namibia (Stejskal et al 2006).…”