To cite spider in a publication, please use:

Brown S. D. J., Collins R. A., Boyer S., Lefort M.-C., Malumbres-Olarte J., Vink C. J., & Cruickshank R. H. 2012. SPIDER: an R package for the analysis of species identity and evolution, with particular reference to DNA barcoding. Molecular Ecology Resources 12:562-565

As spider is developing rapidly, you may want to cite also its version number (found with 'library(help = spider)').

Corresponding BibTeX entry:

  @Article{,
    title = {{SPIDER}: an {R} package for the analysis of species
      identity and evolution, with particular reference to {DNA}
      barcoding},
    author = {Samuel D. J. Brown and Rupert A. Collins and Stephane
      Boyer and Marie-Caroline Lefort and Jagoba Malumbres-Olarte and
      Cor J. Vink and Robert H. Cruickshank},
    journal = {Molecular Ecology Resources},
    year = {2012},
    volume = {12},
    pages = {562--565},
  }