Cost–benefit analysis of improved light trap for harvesting the edible grasshopper, Ruspolia differens (Orthoptera: Tettigoniidae): Evidence from Uganda

Abstract

Recent evidence has shown that improved light traps comprising modified drums and light emitting diode bulbs are more efficient and safer in mass trapping of wild swarms of Ruspolia differens compared to mercury light traps with open-ended drums commonly used in Uganda. However, financial analysis of the improved traps had not yet been conducted prior to this study. Here, we carried out a cost–benefit analysis of the improved trap compared to the existing trapping technique. A pre-tested questionnaire was used to collect data on the demographic characteristics, revenue, capital expenditures and operating costs of the current trapping method from 30 commercial R. differens trappers in Masaka Uganda. The costs and revenue from the improved trap were collected basing on the market price and estimates for the 30 trappers. Net present value (NPV), benefit–cost ratio (BCR) and payback period were computed for the improved and current method and compared using an independent sample t-test. The results revealed that the improved trapping technique was more profitable than the current technique. Moreover, high costs of electricity and harmful non-target insects, especially the Nairobi fly (Paederus sp) which causes dermatitis were other difficulties associated with the current trapping technique. We, therefore, recommend adoption of the improved R. differens trapping technique as a more profitable alternative to the current technique.