Sampling of parasitoid Hymenoptera: influence of the height on the ground

Abstract

Parasitoid hymenopterans are a highly diverse group of insects; therefore, the choice of an adequate sampling method becomes important to achieve a representative species richness of a site. The aim of this work is to evaluate the size and diversity of parasitoids in relation to the height of the Malaise trap placement above the ground of a low deciduous forest from Yucatan, Mexico. Parasitoids were collected from September to October 2015, using three Malaise traps at ground level and other three located right above the others, leaving no space between them, at a height of 1.5 m. The collected specimens were identified at family level. A total of 4083 parasitoids belonging to 31 families were collected, representing 93% of the sample’s completeness, according to Jack 1 estimator; with differences in richness and abundance between trap heights according to rarefaction and fixed effects multifactorial ANOVA, respectively. Bethylidae, Braconidae and Ichneumonidae were the most abundant families. Besides, when analyzing the differences of each family by separate, there were significant results for Bethylidae, Diapriidae and Ichneumonidae with more individuals in the traps at ground level than in the raised ones. In a further analysis, the effect of body size on the capture height was observed. The specimens of larger size belonging to the families Bethylidae, Sphecidae, Sclerogibbidae and Evaniidae were more collected at ground level, on the other hand, the larger sized Ichneumonidae were collected at raised level.

Peering into the Darkness: DNA Barcoding Reveals Surprisingly High Diversity of Unknown Species of Diptera (Insecta) in Germany

“…Altogether, the sampled sites represent a heterogeneous array of habitats typical of southern Germany. The specifics of trap deployment (habitat type, site, orientation, height) strongly influence its catch [40]. Collection dates varied among sites but are detailed in Table A1.…”

“…However, a bias favoring the sampling of some taxa over others is always present, meaning that the community captured with such traps does not depict the true insect community of a sampled site [67]. Furthermore, the setup of a Malaise trap in terms of site choice, orientation, and above-ground-level is another source of bias, and these factors strongly influence sampling results [40]. To incorporate such variations, we used different approaches for extrapolating species numbers including Chao1 estimate calculations, which consider the unsampled taxa present at the sampling sites.…”

Ecosystem type might mask the effect of ecosystem recovery on parasitoids’ biodiversity quality

“…Further, to evaluate how human-induced disturbances are impacting on rainforests, it would be important to sample in the different vertical strata, since invertebrates in the canopy seem to be more sensitive to these perturbances than those from the understory (Whitworth et al 2018). In parasitoid Hymenoptera, the height from the ground where the trap was installed may significantly influence the species composition (Chan-Canché et al 2020).…”

Abundant, diverse, unknown: Extreme species richness and turnover despite drastic undersampling in two closely placed tropical Malaise traps

“…4b), meaning that the differing vegetation at each trap site could be a driving factor behind high species turnover (Stuntz et al, 2002). Moreover, because Malaise traps capture insects that happen to fly through a very limited area, various factors such as trap location, orientation, height based on vegetation, light exposure and surrounding structures also have a direct effect on captured communities (Chan-Canché et al, 2020;Steinke et al, 2021).…”