Bird predation on Rhyacionia buoliana Schiff. (Lepidoptera: Tortricidae) larvae in young Pinus radiata D. Don plantations in Southern Chile

Abstract

There are several cases in the international literature about bird predation on pest insects throughout their different development stages (i.e. egg, larvae, pupae). Those cases indicate that occasionally certain insect populations can be controlled through the predation effect by bird assemblages. In southern Chile, the pine shoot moth Rhyacionia buoliana has been controlled mainly by an introduced parasitoid and some natural biocontrollers. From a total of nine Passerine bird species caught at two young pine plantations (established in 1990 and 1991 respectively), only the Black-chinned Siskin (Carduelis barbata) significantly included larvae of pine shoot moth in its diet, with a maximum daily consumption rate of 54 larvae per bird during October. This predatory behavior decreased towards late November. Densities of C. barbata fluctuated from 7 to 18 birds/ha in 1990 and 1991 plantations respectively. For each of these plantations the total consumption was 90 and 228 larvae/ha/day.