Author
Hagler, James | |
Machtley, Scott | |
Blackmer, Felisa |
Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/10/2014 Publication Date: 1/1/2015 Publication URL: http://handle.nal.usda.gov/10113/60080 Citation: Hagler, J.R., Machtley, S.A., Blackmer, F. 2015. A potential sampling error associated with insect protein mark-capture data. Entomologia Experimentalis et Applicata. 154:28-34. Interpretive Summary: Knowledge of insect movement within agricultural production systems is important for effective pest management. Insect dispersal is often studied using marked insects, but the marks must be easily and unmistakably detectable. Markers based on immunoproteins (specific proteins that can be chemically detected in minute quantities) possess these qualities. However, the protein detection assays are so sensitive that there is a chance that unmarked insects can be contaminated by marked insects during the sample collection and handling processes. If this frequently occurs, then any data collected would be compromised. Previously, ARS scientists at Maricopa, AZ found that three inexpensive and commonly available proteins (egg white, cow milk, and soy milk) were effective and durable markers of lady beetle adults. In this study, they determined that only a small number (<1%) of unmarked insects are likely to obtain the marker protein from previously marked lady beetles during the sweep net collection and sample handling processes. Such quality control information provides assurance to researchers of the validity of results of large-scale studies of insect movement using these protein markers. Technical Abstract: Various types of protein spray solutions have proven effective for externally tagging arthropods for mark-release-recapture (MRR) 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. Arthropods were collected in sweep nets from an alfalfa field that also contained 10 egg white-, 10 bovine milk-, 10 soy milk-, and 10 water (control)-marked Hippodamia convergens Guerin Meneville (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 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 5.1 and 22.1% of the soy milk and bovine milk-marked H. convergens (color-coded beetles) lost their mark during the collection and sample handling processes, respectively. |