Are gardens effective in butterfly conservation? A case study with the pipevine swallowtail, Battus philenor

  • Published source details Levy J.M. & Connor E.F. (2004) Are gardens effective in butterfly conservation? A case study with the pipevine swallowtail, Battus philenor. Journal of Insect Conservation, 8, 323-330.


This study is summarised as evidence for the following.

Action Category

Plant parks, gardens and road verges with appropriate native species

Action Link
Butterfly and Moth Conservation
  1. Plant parks, gardens and road verges with appropriate native species

    A replicated, site comparison study in 2001–2002 in 32 gardens and 20 mixed woodlands in California, USA (Levy & Connor 2004) found that California pipevine Aristolochia californica planted in gardens was used less by pipevine swallowtails Battus philenor and had lower egg and caterpillar survival compared to that in natural sites. Adult swallowtails visited fewer gardens (9/32) than natural sites (19/20) where pipevine occurred, and eggs were laid in fewer gardens (7/32) than natural sites (19/20). Egg survival was lower in gardens (42–70%) than in natural sites (57–91%). Adult and egg presence were higher where pipevines were at least 7- (adults) and 17-years-old (eggs), and egg and caterpillar survival were higher at sites with older (>40 years) and larger pipevines (>185 m2 of foliage) than in recently planted sites (data presented as model results). Egg densities were higher on pipevines grown in the sun (2–5.5 eggs/m2/week) than in the shade (0–2 eggs/m2/week). In 2001, nine gardens where pipevine had been planted and nine riparian oak woodland and redwood forests with naturally occurring pipevine were selected. In 2002, twenty-three gardens and 11 natural sites were studied. From March–July 2001–2002, pipevine foliage at each site was inspected for >15 minutes/week, and all swallowtail eggs, caterpillars and adults recorded. In 2002, the number of eggs/m2 of foliage growing in the sun and shade at four garden and four natural sites was counted weekly for 12 weeks, and the survival of marked egg masses was recorded.

    (Summarised by: Andrew Bladon)

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