Abstract
Cowpea, Vigna unguiculata (L.) Walp. (Fabales: Fabaceae), and tomato, Solanum lycopersicum L. (Solanales: Solanaceae), are two economically important crops in the southern United States. The southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae) is a highly polyphagous pest that attacks a wide range of crops including cowpea and tomato causing a reduction in yield and produce quality. Considering the damage and the associated losses in cowpea and tomato production by this and other pests, as well as the demand for reduced use of pesticides, there is a need to cultivate varieties that are resistant to N. viridula. One key indicator of resistance is host nutritional availability and adequacy. This study evaluated the effect of two selected varieties of cowpea and tomato on the growth and development of N. viridula under laboratory conditions as a first step towards the assessment of nutritional adequacy of both crops. We carried out feeding experiments to compare food utilization and suitability by various life stages of N. viridula. The food substrates tested included fresh immature cowpea pods, fresh cowpea seeds, dry cowpea seeds and newly ripened tomato fruits. Overall, mean nymphal mortality was less when reared on cowpea (63.7±2.9%) than tomato (83.0±1.8%). Nymphs required less time to complete development on cowpea (27.8±2.8d) than on tomato (45.0±3.9d). Fresh body weight at adult emergence was greater on cowpea (132.3±12.1mg) than tomato (83.9±1.5mg). Consumption index (CI) and growth rate (GR) were higher on cowpea (CI: 22.0 ±1.3; GR: 2.1±0.3) than tomato (CI: 8.7±1.4; GR: 0.9±0.1). Collectively, these results suggest that cowpea provided a more suitable nutritional substrate for nymphal development. Many small vegetable growers cultivate both crops.
Highlights
Southern green stink bug, Nezara viridula (L.), is one of several polyphagous pentatomid insect pests that attacks a wide variety of crops that include cowpea and tomato [1,2,3,4,5,6]
On fresh seeds the total developmental time (TDT) of nymphs that fed on Mississippi Silver (MS) was 21.8-23.3d which was not significantly longer (t=1.19; df=2; P>0.05) than that on Pinkeye Purple Hull (PPH) (19.3-22.0d) (Table 1)
Biochemical analyses are needed to determine the major factors that may be impeding the development of N. viridula in these varieties. These results indicate that cowpea is more suitable host plant for Nezara viridula than is tomato as indicated by the various metrics examined in this study
Summary
Nezara viridula (L.), is one of several polyphagous pentatomid insect pests that attacks a wide variety of crops that include cowpea and tomato [1,2,3,4,5,6]. In the United States the southern green stink bug is an important pest that feeds primarily on seeds, fresh pods and immature fruits and sporadically on the tender shoots of several crop species [7,8,9,10]. Feeding damage often results in deterioration of fruit and seed quality and significant yield loss in many crops [11,12,13]. Feeding may result in premature fruit drop, delay in crop maturity and reduced seed quality or quantity [15].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
