Abstract
Chorus cicada Amphipsalta zelandica (Boisduval) is an endemic species that is widespread in native and exotic forest and in some horticultural crops. Life-history data were collected in kiwifruit orchard blocks during 2004–2013 with the aim of informing future studies on the biology and management of chorus cicadas. Fifth instar nymphs constructed vertical pre-emergence burrows ending 45±20 mm (mean±one standard deviation) from the soil surface from mid-December to early January. Most adults emerged between early January and late February, with males emerging before females. Peak dates for emergence and oviposition varied with year from 13 January to 4 February and from 31 January to 17 February, respectively. Nearly all newly eclosed adult females had no developed oocytes. Potential fecundity based on counts of mature oocytes in females was 278.5±88.5. Hatching occurred between late May and mid-December, giving a wide range of egg development of 100–326 days. Nymphs were reared from newly hatched first instars to adults on potted plants. Host plant influenced survival of nymphs in their first year, with perennial ryegrass superior to kiwifruit and broadleaf dock. The life-cycle length was 3 or 4 years consisting of 2–3 weeks as an adult, 3–10 months as an egg and either 25–32 months or 37–44 months as a nymph.
Acknowledgements
We are grateful to Plant & Food Research reviewers for valuable comments on the draft, and to Duncan Hedderley for checking statistical analyses.
Funding
Funding for the final year of this study was received from the Plant & Food Research core kiwifruit research programme and a Kiwifruit Royalty Investment Project.