Publication
Variation in the diversity and richness of parasitoid wasps based on sampling effort
Publisher:
PeerJ
Date:
05-04-2018
DOI:
10.7717/PEERJ.4642
Abstract: Parasitoid wasps are a mega- erse, ecologically dominant, but poorly studied component of global bio ersity. In order to maximise the efficiency and reduce the cost of their collection, the application of optimal s ling techniques is necessary. Two sites in Auckland, New Zealand were s led intensively to determine the relationship between s ling effort and observed species richness of parasitoid wasps from the family Ichneumonidae. Twenty traps were deployed at each site at three different times over the austral summer period, resulting in a total s ling effort of 840 Malaise-trap-days. Rarefaction techniques and non-parametric estimators were used to predict species richness and to evaluate the variation and completeness of s ling. Despite an intensive Malaise-trapping regime over the summer period, no asymptote of species richness was reached. At best, s ling captured two-thirds of parasitoid wasp species present. The estimated total number of species present depended on the month of s ling and the statistical estimator used. Consequently, the use of fewer traps would have caught only a small proportion of all species (one trap 7–21% two traps 13–32%), and many traps contributed little to the overall number of in iduals caught. However, variation in the catch of in idual Malaise traps was not explained by seasonal turnover of species, vegetation or environmental conditions surrounding the trap, or distance of traps to one another. Overall the results demonstrate that even with an intense s ling effort the community is incompletely s led. The use of only a few traps and/or for very short periods severely limits the estimates of richness because (i) fewer in iduals are caught leading to a greater number of singletons and (ii) the considerable variation of in idual traps means some traps will contribute few or no in iduals. Understanding how s ling effort affects the richness and ersity of parasitoid wasps is a useful foundation for future studies.