Neocypholaelaps novaehollandiae Evans (Acari: Ameroseiidae) rediscovered: experiments on its life history and behaviour

Abstract

Members of Neocypholaelaps are pollenophagous and phoretic on a range of hosts. In New Zealand, Neocypholaelaps novaehollandiae Evans have been previously collected on native bellbirds and honeybees. The lack of information about this species triggered our interest in its life history and behaviour. We sampled mites from flowers of the nīkau palm (Rhopalostylis sapida), and subjected female mites (isolated in cells) to different diet treatments to determine the diet effects on mite survival. The survival of N. novaehollandiae was a maximum of 18 days in control to 33 days and 29 days on a diet of reed pollen and honey solution, respectively. We paired 20 males and females together in individual Eppendorf tubes and compared this with 20 single females in individual Eppendorf tubes. We demonstrated that unpaired females did not lay eggs but paired females oviposited in their cells, proving that mating is required for oviposition. We observed that six out of 10 samples contained only females (based on 2012 field surveys and preserved specimens in the New Zealand Arthropod Collection, NZAC). In samples with males, an incredibly female-biased sex ratio was found from both sources; 8.33% and 7.70% of males in two samples from the NZAC, and 2.42% and 13.10% of mites in two field samples. We observed that males display exceptional sexual dimorphism; in particular, the enlarged hind legs, which suggests male–male competition. We also report the first coleopteran host association of N. novaehollandiae with the endemic giraffe weevil (Lasiorynchus barbicornus). Further research is needed to understand the sexual dimorphism, extreme sex ratio and the genetic mating system of this species.

Keywords:

• diet manipulations
• mites
• pollen feeder
• pseudo-arrhenotoky
• survival analysis

Acknowledgements

We thank Dr Nicolas Martin (Landcare Research, Auckland) for collecting the initial population of Neocypholaelaps novaehollandiae from nīkau flowers and Dr Qing-Hai Fan (Plant Health & Environment Laboratory, The Ministry for Primary Industries, Auckland) for mite identification. This research was supported by Core funding for Crown Research Institutes from the Ministry of Business, Innovation and Employment's Science and Innovation Group.