A comparison of pitfall traps and hand-picking techniques for studying macroathropods abundance in vegetable plots and the influence of abiotic factors on their abundance in Jos, Nigeria

Soil macroarthropods are important components that sustain the health and quality of agro-ecosystems for improved agricultural productions though are influenced by abiotic components of the environment. Macroarthropod collections vary across traps due to the fact that some traps can stand for a long time while others such as handpicking cannot. However, traps may be used as a rapid assessment tool to generate checklists for macroarthropod species present in an area within a very short time. To this end, a study on the comparison of pitfall traps and hand-picking techniques for studying macroathropods abundance in vegetable plots and the influence of abiotic factors (temperature and pH) on their abundance in Jos, Nigeria was carried out from August to October, 2014. Pitfall traps and hand-picking techniques were used to collect macroarthropods from six different vegetable plots in three selected villages in Jos North Local Government Area of Plateau State, Nigeria. Soil temperature was recorded in the field while soil samples were obtained from a 7.5 cm depth for measurement of soil pH in the laboratory. A total of 3,346 macroarthropods were collected and pitfall traps had 2,780 (83.08%) while handpicking technique recorded 566 (16.92%). There was a significant difference (P = 0.0076) in the mean abundance of macroarthropods between sampling techniques. Macroarthropods abundance and species richness in relation to vegetable plots varied significantly (P < 0.0001). There was a positive association between pH and macroarthropod abundance (r = 0.13) while temperature did not influence the abundance (r = -0.08). Although, pitfall trap is a passive collector of macroarthropods, it is still a more efficient and preferred sampling techniques for ground crawling arthropods. Farmers should ensure that their soil pH is well maintained at alkaline level so as to influence macroathropods abundance in vegetable plots and ensure robust productivity.