Preliminary sampling of arthropod fauna of transgenic cassava in confined field trial

Abstract

Water (Basin and pitfall) and sweepnet traps were used to ascertain the population dynamics of the arthropod fauna of transgenic cassava in a confined field trial (CFT) at National Root Crops Research Institute  (NRCRI), Umudike, Nigeria. The trial took place from August to November, in 2009 and February to July, in 2010 to identify the major arthropods  associated with the crop and to monitor changes in their populations for effective management. Trapped arthropods were sorted and identified by means of a hand lens and a taxonomic key and their relative abundance determined. Most of the order (seven out of the eight recorded) were  trapped in the basin and sweepnet traps. Twenty families and numerous mostly unidentified genera and species were collected during the sampling period. Isoptera were the most abundant group, most of which were  trapped while foraging and prospecting for nectar, mate, oviposition site, or were accidentally caught. This was followed by Coleoptera and  Orthoptera. The least abundant order was Spirostreptida. Basin traps capture the highest number of arthropods of diverse families, followed by pitfall then sweepnet. A lower arthropod weekly mean abundance was recorded in 2009 (129.55) than in 2010 (132.08).

Key words: Arthropod, fauna, pitfall, sampling, sweepnet, transgenic cassava.