Detection of shield beetle remains in predators using a monoclonal antibody

Abstract

Cassida rubiginosa Muell. (Col., Chrysomelidae) is considered to be a native biocontrol agent of the creeping thistle, Cirsium arvense (L.) Scop, one of the world's worst weeds. However, predation is a major mortality factor in C. rubiginosa populations and prevents high beetle densities in nature. We determined temperature-dependent detection periods of shield beetle remains within predators by immunological gut analysis, in order to define the time period within which predation must have occurred. We conducted feeding trials with the model predators Nabis mirmicoides Costa and Chrysopa carnea Stephen at two and three different temperatures, respectively, using C. rubiginosa larvae as prey. Indirect enzyme-linked immunosorbent assay (ELISA) was used to examine the predators for the presence of prey antigen. The monoclonal antibody (MAb) CRL5-1 clearly identified predation by N. mirmicoides for up to 47 h and by C. carnea up to 96 h post-feeding at 15°C. An exponential decay gave a good description of the antigen time course within predators. Calculated detection periods for the antigen were 234.7 h at 15°C and 85.0 h at 20°C in N. mirmicoides and 215.3 h (15°C), 91.9 h (20°C) and 79.1 h (25°C) in C. carnea. The reported detection periods of prey remains in predators are the longest known in immunology, and are much higher than the recently published detection periods of prey DNA in predators. Therefore MAb CRL5-1 is a highly valuable tool for quantifying predation in the field.

Picky predators and the function of the faecal shield of a cassidine larva

“…This was unexpected, because in laboratory experiments ants, lacewings and bugs readily attacked C. rubiginosa larvae and fed on them (Eisner et al . 1967; Bacher, Schenk & Imboden 1999; Schenk & Bacher 2004). Perhaps in the field the predators did not regard larvae with a faecal shield as potential prey.…”

Advances in molecular ecology: tracking trophic links through predator–prey food‐webs

“…Harwood et al . 2001a; Schenk & Bacher 2004) compared with the relatively short ones for prey DNA (e.g. Agustí et al .…”

The detection and decay of Cry1Ab Bt-endotoxins within non-target slugs,Deroceras reticulatum(Mollusca: Pulmonata), following consumption of transgenic corn

“…Although this time period was shorter than the detection of prey proteins in some predators (e.g. Harwood et al 2001Harwood et al , 2004Schenk & Bacher 2004), it was sufficiently long to allow potential transfer of insecticidal material along the food chain. The sensitivity of the assay, allowing the detection of very small concentrations (and therefore quantities) of Cry1Ab-endotoxin for this length of time, indicates its viability in field studies for measuring the uptake of insecticidal toxins by non-target species.…”

“…The hypothesis that the breakdown of Cry1Ab endotoxins in slugs would be sufficiently slow to indicate the potential for transfer of endotoxins to higher trophic level organisms (e.g., birds, hedgehogs, insect predators and spiders) was therefore tested. This hypothesis is based on the ability of antibody-based assay systems to detect target proteins in gut samples for significant periods after consumption of food (e.g., Symondson et al 1999Symondson et al , 2000Harwood et al 2001Harwood et al , 2004Schenk & Bacher 2004).…”