The Sweet potato weevils of the genus Cylas are the most destructive pests of sweet potato and are widely distributed in Africa. The aim of this study was to identify and document the species of Cylas occurring in sweet potato production zones in Ghana. A survey was conducted in 23 localities in 2015 from July to December in seven regions in Ghana in order to determine the identity of the pest. We collected nine thousand and two specimens from Central, Eastern, Greater-Accra, Northern, Volta, Upper-East, and the Upper-West regions. Two species were identified: Cylas brunneus Fabricius, 1797 and Cylas puncticollis Boheman, 1833. Cylas puncticollis occurred in all regions and represented 6,107 specimens (68%), while 2,895 of the specimens (32%) could be assigned to C. brunneus. The latter is restricted to the southern sector including Volta, Central, Eastern and Greater Accra Regions. When considering both species in the southern sector, the Volta Region accounted for 3,117 specimens (48%) followed by 1,447 (22%), 987 (15%), and 980 (15%), from the Central, Eastern, and Greater-Accra Regions, respectively. The dominant species in southern and northern sector was C. puncticollis.
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RBINS Staff Publications 2016
Two commercially valuable holothurians, the sandfish and golden sandfish, vary in colour and have a confused taxonomy, lending uncertainty to species identifications. A recent molecular study showed that the putative variety Holothuria (Metriatyla) scabra var. versicolor Conand, 1986 (‘golden sandfish’) is a distinct species from, but could hybridize with, H. (Metriatyla) scabra Jaeger, 1833 (’sandfish’). Examination of the skeletal elements and external morphology of these species corroborates these findings. The identity of H. (M.) scabra is unambiguously defined through the erection and description of a neotype, and several synonyms have been critically re-examined. The nomenclaturally rejected taxon H. (Metriatyla) timama Lesson, 1830 and H. (M.) scabra var. versicolor (a nomen nudum) are herein recognized as conspecific and are allocated to a new species, Holothuria lessoni sp. nov., for which type specimens are described. The holotype and only known specimen of H. aculeata Semper, 1867, has been found and is redescribed. It is considered to be a valid species. Taxonomic clarification of this heavily exploited species complex should aid its conservation and permit species-specific management of their fisheries.
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