A comparative study of the retention and lethality of the first and second generation arthropod protein markers

A greenhouse study was conducted that compared the protein mark retention time of a well-established rabbit IgG protein detection protocol with those of three newer, less expensive protein detection protocols designed to detect casein in bovine milk, egg albumin in chicken egg whites, and soy trypsin in soy milk, respectively. Adult convergent lady beetles, Hippodamia convergens Guérin-Méneville (Coleoptera: Coccinellidae), were topically marked with either 2.0 ml of a 5.0 mg ml^-1 rabbit IgG solution or 2.0 ml of pure bovine milk, chicken egg whites, or soy milk solutions. The variously marked cohorts of beetles were then released into cages that contained a single cotton plant. In turn, beetles were collected every other day for 26 days after marking and assayed for the presence of the protein marks by either a sandwich anti-rabbit IgG enzyme-linked immunosorbent assay (ELISA) or an indirect anti-casein, anti-egg albumin, or anti-soy trypsin ELISA to detect bovine casein, chicken egg albumin, or soy milk trypsin, respectively. Data indicate that the durability of the protein markers on the beetles decreases in the following order: egg whites > rabbit IgG > milk > soy milk. In addition, the mortality of H. convergens after receiving each protein mark treatment was assessed. Data revealed that there were no significant differences in mean mortality of beetles between any of the protein treatments. Overall mortality during the course of the 26-day study ranged from 30% for the soy-marked beetles to 50% for the water and rabbit IgG-marked beetles.