Density and Diversity of Insects That Visit Cashew (Anacardium occidentale L.) Plants in the Flowering and Fruiting Periods in Northern Ghana

Abstract

Field survey was conducted in ten farms in Northern Region from December 2014 to April 2015 to collect, identify and access the insects distribution on the cashew farms close to natural forest and agricultural farm land, during the flowering and the fruiting periods of cashew. The sample farms were divided into four plots measuring 20 m x 25 m. Insects found on the cashew plants during the flowering and fruiting periods were identified, counted and unidentified insects were killed in killing jars and preserved in 70% alcohol for further identification. The following were the insects encountered in both farms during the flowering period: Total insects 6161, mean 1232.2 (SD = 250.7, N = 40). Density was 6161/ha and diversity was 3.34. Total insect 2745, mean 549 (SD = 103.2, N = 40). Density was 2745/ha and diversity was 3.56. During the fruiting period, the following insects were also enumerated in both farms: Total 4665, mean 933 (SD = 143.5, N = 40). Density was 4665/ha and diversity of 3.13. Total 2056, mean 411.2 (SD = 52.1, N = 40). Density was 2056/ha and diversity was also 3.14. Density in both farms during the flowering period were more than the fruiting period in both farms, however insect diversity was more during the fruiting period than the flowering period. Further studies should be conducted on an all year round survey to identify residence insects from insects that visit cashew during flowering and fruiting period, integrated pest management strategies and integration of insect conservation into the national biodiversity conservation policy were also recommended.