DOI: 10.5061/dryad.rfj6q57cx
title: Precision glycerine jelly swab for removing pollen from small and fragile insect specimens

description: Historical datasets can establish a critical baseline of plant-animal
 interactions for understanding contemporary interactions in the context of
 global change. Pollen is often incidentally preserved on animals in
 natural history collections. Techniques for removing pollen from insects
 have largely been developed for fresh insect specimens or historical
 specimens with large amounts of pollen on specialised structures. However,
 many key pollinating insects do not have these specialised structures and
 thus, there is a need for a method to extract pollen from these small, and
 fragile insects. Here, we propose a precision glycerine jelly swab tool to
 allow for the precise removal of pollen from old, small, and fragile
 insect specimens. We use this tool to remove pollen from five families of
 insects collected in the late 1970s. Additionally, we compare our method
 with four previously published techniques for removing pollen from pinned
 contemporary specimens. We show the functionality of the precision
 glycerine jelly swab for removing small quantities of pollen across insect
 families. We found that across the five methods, all removed pollen; yet,
 it was clear that some are better suited for fragile specimens. In
 particular, the traditional glycerine jelly swab and the precision
 glycerine jelly swabs both performed well for removing pollen from bee
 faces. The shaking wash resulted in specimen fracture and residue left
 behind, the ethanol rinses left setae matted, and the glycerol swabbing
 left residue on the specimen. Additionally, we present photographs
 documenting the effects of these methods on pinned honey bee specimens.
 The precision glycerine jelly swab opens up opportunities to sample pollen
 from a variety of insects in natural history collections. These pollen
 samples can be incorporated into downstream analyses for pollen
 identification either via microscopy or DNA sequencing, and the resulting
 plant-insect interaction data can establish historical baselines for
 contemporary comparison. Beyond our application of this method to pollen
 on insects, this precision glycerine jelly swab tool could be used to
 explore pollen placement specialisation or to sample bryophyte, fungal,
 and tree fern spores dispersing on animals.
description: Images were captured using a Nikon AZ100M microscope with a
 Digital Sight DS-Ri1 (Nikon Instruments Inc., USA) mounted camera head.
 Stacked images were captured and measurements were taken using the
 NIS-Elements D imaging software (Version 5.02). 
description: Insect_sizes_museum_data_supplement data file
 accession_no – Accession number corresponding to that at the
 Canterbury Museum, Christchurch, New Zealand family –
 Insect family classification – Insect genus and species
 or family, if not identified to that level
 specimen_notes – notes about the specimen
 pollen_visual – whether pollen was observed on the insect
 specimens (1 = yes) size_length_mm – length of the
 specimen in mm collection_date – date the specimen was
 collected location – location within New Zealand where
 the insect was collected country – country from where
 the insect was collected