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Description:
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Laboratory studies were conducted to generate basic biological information of Lygus hesperus on alfalfa , pigweed , Russian thistle , green bean , artificial diet , cotton square and cotton boll . The nymphal development was significantly longest , almost two times longer , in the cotton boll compared to other hosts . The average nymphal development was about 15 days in other hosts except cotton boll at 27 oC . The nymphal survivorship was significantly lowest in the cotton boll . The average total nymphal survivorship was around 60 % and the highest mortalities were focused on the first 3 instars . The sex ratio of the L . hesperus was not affected by the different diets . The life -table parameters were obtained in cotton square , artificial diet , green bean and alfalfa . The adult longevity in artificial diet was shortest (18 .7 days ) for the highest fecundity used up all the energy of the insects and the green beans had the longest longevity (36 .09 days ) . The rm values were higher in artificial diet and green bean , and lower in cotton square and alfalfa . λ values showed the same pattern . Even though all those two parameters were significantly different in cotton square and alfalfa , those two parameters on two hosts were numerically similar . The rest two parameters GRR and Ro showed the same pattern as well . But the T and DT values showed the different pattern caused by the shortest longevity in artificial diets and longest longevity in green beans . All the study showed that cotton , especially cotton square can offer enough nutrition to let L . hesperus grow during the early summer in the field . |