Development of a standardized protein immunomarking protocol for insect mark–capture dispersal research

Abstract

A field study was conducted to test the marking efficiency of broadcast spray applications of protein marks on stationary (represented by cadavers) and free‐roaming lady beetles Hippodamia convergens Guérin‐Méneville that were strategically placed in blooming alfalfa plots. The marks tested included three different concentrations of egg albumin from chicken egg white, casein from bovine milk and trypsin inhibitor from soy milk. The cadaver and free‐roaming beetle treatments served to measure the acquisition and retention of each protein treatment regime by direct contact with the spray solution and by residual contact with protein‐marked residue on alfalfa, respectively. In addition, the vertical distribution of marking efficacy was determined by sampling alfalfa plant tissue and beetle cadavers that were located on the upper and lower portion of the plant canopy. The data indicated that the backpack spray apparatus was very effective at uniformly administering the various protein marks, regardless of the concentration, throughout the entire plant canopy. Also, the free‐roaming beetles readily self‐marked by contact exposure to protein‐treated plants. We also identified concentrations of each protein type that will mark about 90% of the resident beetle population. Moreover, if a mark–capture‐type study only requires two unique protein marks, we determined that concentrations of 25% for egg white and 100% for bovine milk could be used to mark 98% of the population. Our results provide a significant step towards standardizing protein immunomarking protocols for insect mark–capture dispersal research. In addition, we identify several areas of research that are needed to further standardize the protein mark–capture procedure.

A potential contamination error associated with insect protein mark‐capture data

“…These results support previous studies that showed that egg white is a more steadfast mark than bovine and soy milk (Jones et al, 2006;Hagler & Jones, 2010;Slosky et al, 2012;Hagler et al, 2014).…”

“…However, 22.1 and 5.1% of the bovine milk‐ and soy milk‐marked H. convergens , respectively, did not retain their mark. These results support previous studies that showed that egg white is a more steadfast mark than bovine and soy milk (Jones et al., ; Hagler & Jones, ; Slosky et al., ; Hagler et al., ).…”

“…for 1 h (27 °C) using an orbital shaker. Every arthropod sample was then screened for the presence of egg albumin in egg white, casein in cow milk, and soy trypsin inhibitor in soy milk using the assays described by (Hagler et al., ) with only one slight modification. The modification consisted of adding 100 μl of hydrogen peroxide to each ELISA sample well for 30 min between the first step of the ELISA (i.e., after the arthropod sample incubated for 1 h in the well of the plate) and the blocking step.…”

Administering and Detecting Protein Marks on Arthropods for Dispersal Research

“…Specifically, they showed that different water sources, additives (surfactants), and even the type of ELISA plate used affected (either positively or negatively) the assay. Moreover, that study and subsequent studies 37,39,40 showed that the three protein mark detection assays vary in efficacy. The egg white marker was retained longer than the milk marker, which was retained longer than soy milk marker.…”

“…Future users of the immunomarking technique should ensure that their methodology is suitable to the specifics of their research. The concentration and volume of the mark needed and how the mark is applied will depend on factors like behavior, body type and size of the target species 40 .…”