Comparative efficiency of traps for horse fly (Diptera: Tabanidae) survey in riparian oak-ash forests in Danube floodplain

Abstract

The objective of this work was to evaluate the relative trap efficiency of the three modified traps baited with 1-octen-3-ol as attractant, Box, Nzi and Canopy, for horse fly (Tabanidae) survey. Nine traps (three traps per trap type) were tested in 3 × 3 Latin square designs during summer 2011 in riparian oak-ash forests in the Danube floodplain of Croatia. Overall, the traps caught 1,986 specimens of 11 horse flies species during the study period. The most abundant species caught was Tabanus bromius (58%), followed by Tabanus tergestinus (21%), Tabanus maculicornis (16%), Tabanus sudeticus (2%), Atylotus loewianus (1%) and Tabanus autumnalis (1%). Both the Box traps and the Nzi traps had significantly greater catch efficiencies than the Canopy traps (βbox = 2.47, X2 = 65.48, df = 1, P < 0.001 and βnzi = 1.54, X2 = 25.12, df = 1, P < 0.001, respectively). Nzi traps had a catch rate 4.65 (95% CI: 2.55, 8.48) times greater than Canopy traps and Box traps had a catch rate 11.77 (95% CI: 6.48, 21.39) times greater than Canopy traps. Based on Shannon-Wiener diversity indices Nzi traps were better suited for diversity survey and had higher (H' = 1.33) indices than Box (H' = 1.08) or Canopy traps (H' = 1.00).