Composition and distribution of dragonflies and damselflies (Insecta: Odonata) in Iloyin Forest, Akure, Southwestern Nigeria

Odonate fauna of Iloyin Forest was studied from October to December 2009 to have an overview of the species composition and distribution with the threat of deforestation in the area. Adult species were collected once a week using a sweep net throughout the period of the study from three study sites (denoted as I, II and III) with varying levels of anthropogenic disturbance. A total of 76 species belonging to eight families were recorded in the forest. The two most abundant families in the forest were the Libellulidae (Anisoptera) and Coenagrionidae (Zygoptera).  Palpolpeura portia, P. lucia and Congothemis dubia were the dominant species of Libellulidae, while Pseudagrion kersteni was the dominant coenagrionid.   Some species of Odonata usually associated with shaded forests were encountered in two of the study sites. The highest diversity and evenness indices were recorded at Site I, followed by Site II and the least recorded at Site III. Although shade-loving species recorded in the study area was an indication of its richness in forest Odonata, some may have however become locally endangered or extinct as a result of deforestation. A check in the rate of deforestation could preserve the few forest (endangered) species and restore the locally extinct ones that changed habitats. Key Words:     Biodiversity, Conservation, Disturbance, Forest, Freshwater, Odonat

Field evaluation of Cowpea (Vigna unguiculata (L.) Walp) varieties for resistance to some major insect pests in Ago-Iwoye, South west Nigeria

Field trials to screen twelve varieties of cowpea for resistance to major insect pests were conducted over two planting seasons (2002 and 2003) at the Teaching and Research Farm of the College of Agricultural Sciences, Olabisi Onabanjo University, Ago-Iwoye. Results showed that varietal resistance to insect pests in cowpea varied with growth stages and seasonal changes. Five major insect pests (Aphis craccivora, Megalurothrips sjostedti, Maruca vitrata, Riptortus dentipes and Clavigralla tomentosicollis) were observed at the various stages of growth of cowpea plant. Results suggest that the cowpea variety IT90K-277-2 was resistant to Aphis craccivora while IT86D-719 was resistant to Megalurothrips sjostedti. Maruca vitrata did not pose any threat to most of the cowpea varieties tested. IT95M-118, IT86D-719, IT95M-120 and IT95M-220 were resistant to Riptortus dentipes, a pod-sucking pest. The pod evaluation index showed that IT95M-118 and IT84E-124 were resistant to pod sucking insects. The highest pod and peduncle damage were recorded on variety IT95M-120. Keywords: Cowpea; Major Insect pests; Resistanc