HORGAN FG,CHÁVEZ JC. 2004.Field boundaries restrict dispersal of a tropical tiger beetle,
Megacephala angustata
Chevrolat 1841 (Coleoptera;Cicindelidae). Entomotropica 19(3): 147-152.
Field boundaries may divide populations of predatory invertebrates into local populations at the field scale by restricting between-field dispersalThis could reduce recolonisation rates after pesticide use or decrease the efficiency of numerical responses by natural enemies to pest outbreaks.The present study examines the impact of field boundaries on dispersal of the predatory tiger beetle,
Megacephala angustata Chevrolat 1841 at a farm in coastal El Salvador. Pitfall trapping indicated that beetles occurred in most habitats on the farm. In pastures, captures were higherin open, unshaded areas than under field boundaries. Beetle dispersal was examined in a capture-mark-recapture study at the site. Movement between fields was very rare as indicated by a linear relationship between the accumulated number of marked beetles and the proportion of recaptures in each of three fields. In spite of frequent recaptures, three weeks after marking, only 2 of 401 beetles were found outside the fields where they had been originally captured and marked.