Screen-House Rearing of the Cashew Mirid Helopeltis Schoutedeni Reuter (Heteroptera: Miridae) on Three Vegetables for its Management on Cashew

Abstract

Helopeltis schoutedeni (Heteroptera: Miridae) is a significant cashew and cotton pest in East and West Africa. To date, viable laboratory rearing and maintenance protocols have been lacking to facilitate biological investigations on the bug. This drawback has largely hindered its successful management. The potential of three vegetable intercrops, cucumber fruit (Cucumis sativus L.), fresh French bean (Phaseolus vulgaris L.) pods, and pigeon pea (Cajanus cajan L.) were the suitable host plants for establishing laboratory colonies of H. schoutedeni. The developmental time, survival, oviposition, and feeding behaviors of H. schoutedeni under screen-house conditions were monitored. Newly hatched nymphs reared on these substrates successfully developed into adults with varying average developmental times of 25.72, 25.81, and 33.26 days for French beans, pigeon peas, and cucumbers, respectively. Similarly, survival varied significantly on the different plants, with the highest survival occurring on pigeon pea seedlings (97–100%) and the lowest on cucumber (48–69%; P < 0.05). Significantly more feeding lesions were recorded on pigeon peas (349.6 ± 82.56) than on cucumbers (52.6 ± 13.62) in the feeding preference test. The proportion of adult feeding during the scotophase was significantly higher than in the photophase (Pigeon pea seedling: t = −3.545; df = 18; P < 0.05, French beans: t = −2.684; df = 28; P < 0.05 and Cucumber t = 3.713; df = 18; P < 0.05). Oviposition was only recorded on pigeon pea seedlings. Present findings demonstrate the potential for using specific vegetables as suitable host plants for H. schoutedeni under confined and open field settings to aid future research studies toward effective management.