Fall armyworm (FAW; Spodoptera frugiperda), an exotic moth which recently invaded Africa, is a highly destructive pest of cereals especially maize a highly valued staple crop in Nigeria. The use of natural enemies such as predators or parasitoids for FAW control is more economically viable and environmentally safer than currently recommended synthetic insecticides. Natural enemies to combat the pest have not yet been reported in Nigeria. An exploration for the pests’ natural enemies was undertaken by collecting FAW eggs and larvae from maize fields. These were reared in the laboratory for emergence, identification and efficacy as natural enemies. This yielded Euplectrus laphygmae (Hymenoptera: Eulophidae); Telenomus remus (Hymenoptera: Platygastridae) and Trombidium sp. (Acari.: Trombidiidae). Cotesia or Apanteles spp. were inferred to occur since Stictopisthus sp. (Hym.: Ichneumonidae), a secondary parasitoid, that attacks cocoons of Microgasterinae (e.g. Cotesia, Apanteles etc.) also emerged. Species of yet-to-be identified predators were also observed in various niches of maize plants. A positive relationship was found between FAW instar and the number of E. laphygmae eggs/instar ranging, on average, from 1.5 on second instar to 5.5 on fourth instars hosts. Parasitism rate of T. remus on FAW eggs was 100%. Parasitic mite infestation resulted in increasing paleness, reduced feeding, growth and movement as well as death of FAW 1^st instars. Thus, the occurrence of FAW natural enemies in Nigeria calls for advocacy campaign to incorporate their use into integrated pest management strategies that attract and allow natural enemies to thrive for FAW management.

Citrus greening is a serious disease of Citrus sp. and has been associated with the collapse of the several citrus industries in Asia and America (Bové 2006). The disease is associated with the pre...

Pests including nematodes have been reported as a limiting factor to the production of roselle worldwide. A survey of rosellefarmsinsix Northern Sates of Nigeria was conductedin 2013 to identify the diverse nematode species associated with the soils and roots of the plant and determine their population densities on farmers’ fields. Eightsoil and ten plant samples were randomly collected from each of twenty farms from which nematodes were extracted and identified. Four genera of plantparasitic nematodes (Meloidogyne spp., Helicotylenchus spp., Rotylenchulus spp.and Tylenchus spp.) were found in association with roots and rhizosphere of roselle plants. Meloidogyne were most populous (62.29%) on the roots while Tylenchuswas least (1.68%). Helicotylenchus spp appeared in highest density (50.05%) in plant rhizosphere, but not identified from the roots. The highest percentage of nematode population (22.7 %) wasfrom Katsina, followed by Sokoto (21.6%), Jigawa (17.4%), Zamfara (16.5%), Kano (15.1%) and Kaduna states (6.7%).The generally low nematode density observed might be due to low precipitation and high soil temperature of the six states. Occurrence of varied species of nematodes demands effective control measures for improved roselle productivity. Kano, Zamfara and Jigawawith low nematode population densities can be considered for further research towards the establishment of pest-free areas or area of low pest prevalence for roselle nematodes in Nigeria, useful in the agricultural export trade. Further studies are required on the determination of density economic threshold and the definitive roles of nematodes in causing low productivity of roselle. Keywords: Export value, Hibiscus sabdariffa, nematodes, population densities, pest-free area