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

Abstract

Various types of protein-spray solutions have proven effective for externally tagging arthropods for mark-release-recapture and mark-capture type dispersal research. However, there is concern that certain standardized arthropod collection methods, such as sweep netting, might lead to high incidences of protein transfer from field-marked to unmarked arthropods during sample collection and sample handling. Native arthropods were collected in sweep nets from a field of alfalfa, Medicago sativa L. (Fabaceae). The nets also contained 10 egg white-, 10 bovine milk-, 10 soy milk-, and 10 water (control)-marked Hippodamia convergens Gu erin-M eneville (Coleoptera: Coccinellidae) that were visually distinguishable by a yellow, white, green, and blue dot, respectively. The plant debris and arthropods from each sweep net collection were then placed into either a paper or a plastic bag and frozen for storage. The contents of each sweep net sample were thawed and the color-coded H. convergens and field-collected arthropods were examined for the presence of each protein by an egg white (albumin), bovine milk (casein), and soy milk (soy trypsin) enzyme-linked immunosorbent assay (ELISA). Data revealed that only 0.67, 0.81, and 0% of the field-collected unmarked arthropods acquired an egg white, bovine milk, and soy milk mark, respectively. ELISA results also showed that all the egg white-marked H. convergens retained their mark, but 22.1% of the bovine milk-marked and 5.1% of the soy milk-marked H. convergens (color-coded beetles) lost their mark during the collection and sample handling processes.

Evaluating the persistence of fluorescent and protein powders on adult blue orchard bees, Osmia lignaria (Hymenoptera: Megachilidae), for mark-capture studies

“…The combination of different colored powders was necessary for the apiary study, as the number of clearly distinguishable Day-glo® powders is limited. Furthermore, the study revealed no blatant evidence that the powders were transferred between bees from different honey bee colonies, as was further confirmed by Hagler et al (2015). The practice of combining colors for eventual microscopic identification could easily carry over to applications within O. lignaria research activities.…”

A Nonlethal Method to Examine Non-Apis Bees for Mark-Capture Research

“…However, this is unlikely, because arenas contained only female bees that seldom interact through close contact (e.g., no mating attempts, fighting, or sharing of nesting substrates), and no interactions were observed or documented for either species during this study. In previous dispersal research, it was apparent that the risk of netting multiple marked bees in the same net did not result in extraneous transfer of protein materials among individuals ( Hagler et al 2015 ). This outcome suggests a minimal crossover of protein powder between individual solitary bees in the current study, as one could expect a similar level of contact among individuals within arenas.…”

Wanted dead or alive: Scavenging versus predation by three insect predators

“…Of the 164 marked L. hesperusprey recovered from the cages, only two (1.2%) showed evidence of cross-contamination (i.e., they were positive for the IgG marker that they were not marked with). Previous immunomarking studies have shownthere is about a 1.0% assay error rate associated with this procedure (Hagler et al 2014(Hagler et al , 2015b. We have attributed this to human error (e.g., day-to-day variation) when conducting the assays.…”

“…Specifically, an ELISA conducted on an individual predator that was observed feeding on a protein-marked C. carnea larva failed to detect the marker.It should be noted however, that this predator only partially consumed the prey. In all likelihood the predator did not consume enough of the marked prey for detection by ELISA (see Hagler et al 2015b). Future prey immunomarking quality control studies are warranted to determine the frequency with which protein markers transfer to predators that only partially consume their prey.…”