Journal Of Insect Conservation

, Volume 8, Issue 2, pp 229–241

Differential parasitism of seed-feeding Cydia (Lepidoptera: Tortricidae) by native and alien wasp species relative to elevation in subalpine Sophora (Fabaceae) forests on Mauna Kea, Hawaii

  • Peter T. Oboyski
  • John W. Slotterback
  • Paul C. Banko
Article

DOI: 10.1007/s10841-004-1356-x

Cite this article as:
Oboyski, P., Slotterback, J. & Banko, P. J Insect Conserv (2004) 8: 229. doi:10.1007/s10841-004-1356-x

Abstract

Alien parasitic wasps, including accidental introductions and purposefully released biological control agents, have been implicated in the decline of native Hawaiian Lepidoptera. Understanding the potential impacts of alien wasps requires knowledge of ecological parameters that influence parasitism rates for species in their new environment. Sophora seed-feeding Cydia spp. (Lepidoptera: Tortricidae) were surveyed for larval parasitoids to determine how native and alien wasps are partitioned over an elevation gradient (2200–2800 m) on Hawaii Island, Hawaii. Parasitism rate of native Euderus metallicus (Eulophidae) increased with increased elevation, while parasitism rate by immigrant Calliephialtes grapholithae (Ichneumonidae) decreased. Parasitism by Pristomerus hawaiiensis (Ichneumonidae), origins uncertain, also decreased with increased elevation. Two other species, Diadegma blackburni (Ichneumonidae), origins uncertain, and Brasema cushmani (Eupelmidae), a purposefully introduced biological control agent for pepper weevil, did not vary significantly with elevation. Results are contrasted with a previous study of this system with implications for the conservation of an endangered bird species that feed on Cydia larvae. Interpretation of results is hindered by lack of knowledge of autecology of moths and wasps, origins, phylogeny, systematics, competitive ability, and physiological limitations of each wasp species. These factors should be incorporated into risk analysis for biological control introductions and invasive species programs.

Keywords

Alien speciesBiological controlElevation gradientMoth conservationNon-targetParasitism

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • Peter T. Oboyski
    • 1
    • 3
  • John W. Slotterback
    • 1
  • Paul C. Banko
    • 2
  1. 1.Pacific Cooperative Studies Unit (University of Hawai’i atMânoa)USGS Pacific Island Ecosystems Research CenterHawai’i National ParkHawai’i
  2. 2.USGS Pacific Island Ecosystems Research CenterHawai’i National ParkHawai’i
  3. 3.Department of Environmental Science, Policy, and Management, Division of Insect BiologyUniversity of CaliforniaMC3112 BerkeleyUSA