Developmental specialization and geographic structure of host plant use in a polyphagous grasshopper, Schistocerca emarginata (=lineata) (Orthoptera: Acrididae)

• Published in: Oecologia Vol. 120; no. 3; pp. 437 - 445
• Main Authors: Sword, G.A, Dopman, E.B
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin Springer-Verlag 01.08.1999; Springer
• Subjects: Adult insects; Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Community Ecology; developmental stages; developmental variation; Diet; Evolution; Fundamental and applied biological sciences. Psychology; geographical variation; Grasses; Host plants; host specificity; imagos; Insect ecology; Nymphs; Phytophagous insects; Plants; Protozoa. Invertebrata; Schistocerca; Schistocerca emarginata; Swords; Texas; Texas; United States; North America; America; Feeding behavior; Insecta; Orthoptera; Host specificity; Acrididae; Phytophagous; Animal plant relation; Arthropoda; Host plant; Development; Acridoidea; Invertebrata; Geographical variation; Key wordsSchistocerca emarginata; Geographic structure; Developmental variation; Grasshopper
• ISSN: 0029-8549; 1432-1939; 1432-1939
• DOI: 10.1007/s004420050876

Host plant use and availability were determined in early nymphal and adult-stage Schistocerca emarginata (=lineata) (Orthoptera: Acrididae) populations at six localities in Texas, USA. Early instar nymphal populations were feeding almost exclusively on either Ptelea trifoliata (Rutaceae) or Rubus trivialis (Rosaceae). This study represents the first demonstration of a geographic structure of host plant specificity in a polyphagous grasshopper. Recognizing this geographic structure required investigations of both developmental and geographical variation in host plant use. Nymphal diet breadths were significantly less than adult diet breadths at four of six localities and smaller overall when pooled nymphal and adult diet breadths were compared among sites. Neither restricted nymphal mobility nor host plant availability accounted for the observed differences in host plant use between developmental stages and among localities. Evidence suggests that the differences in host use among populations are due to host-plant-associated genetic differentiation.