A Quantitative Study of the Predators on the Eggs and Larvae of the Broom Beetle, Phytodecta olivacea Forster, Using the Precipitin Test

Measuring the Sensitivity of an Indirect Predator Gut Content ELISA: Detectability of Prey Remains in Relation to Predator Species, Temperature, Time, and Meal Size

“…However, even this limitation could be minimized by examining the daily feeding patterns of specific predator species combined with well-timed field collections. Overall, the resolution of measuring predation will depend on a better understanding of the biological characteristics of the predator/prey systems under examination (Dempster, 1960).…”

“…This would decrease the amount of extraneous, nontarget predator proteins present in the sample. Gut and crop dissections have been used before, primarily with large predator species that are relatively easy to dissect (Dempster, 1960;Sunderland et al, 1987;Hagler and Cohen, 1990;Symondson and Liddell, 1995). However, most pink bollworm egg predators are too small and soft bodied to be easily dissected (Hagler and Naranjo, 1994a,b).…”

“…Because many predators and their prey are too small and elusive to observe in nature, researchers have resorted to indirect methods for studying predation (Sunderland, 1987). Indirect methods include microscopic (James, 1961), electrophoretic (Murray and Solomon, 1978), and immunological gut content analyses (Dempster, 1960;Boreham and Ohiagu, 1978). Microscopic gut content analyses are easy and affordable, but are ineffective for most predators because the prey is liquefied or chewed into tiny unrecognizable pieces (Miles, 1972;Pollard, 1990).…”

Cannibalism among green sea urchins Strongylocentrotus droebachiensis in the laboratory and field

“…Wilcox (2012) used this model to estimate predation rates of green crabs on the American lobster Homanus americanus, modifying the equation from earlier work by Dempster (1960), who formulated the equation as the proportion of predators that consumed the prey item of interest, as indicated through gut smears, multiplied by the predator population density. The modified equation from Wilcox (2012) is given below: (1) where N is the predation rate, in this case the number of young sea urchins (<10 mm TD) consumed by adult conspecifics for the given time period and area, and is determined by the decaying probability of detection in the gut contents; D is the half-life of detection (Wilcox 2012); p is the proportion of individuals (in this case adult sea urchins) in the field sample that had consumed the prey item (cannibalized young sea urchins, as assessed by gut analyses), P is the density of predators (adult sea urchins), and t is the time period.…”

Tracing prey origins, proportions and feeding periods for predatory beetles from agricultural systems using carbon and nitrogen stable isotope analyses

“…Tracing diet origins and migration or movement of natural enemies, represents a fundamental aspect for their effective conservation and a precondition for their biological control (Hobson, 1999;Hood-Nowotny and Knols, 2007). Methodologies for determining the nutritional source fed upon by a herbivore or predator include direct observation of feeding insects (Petelle et al, 1979), gut content analysis (Isely and Alexander, 1949;Marples, 1966), antigen-antibody reaction measurement (Dempster, 1960), radioisotope (Marples, 1966) or biological pigment tracer studies (Putman, 1965) and intrinsic markers (such as naturally occurring stable isotopes, molecular DNA and fatty acid profiles) in animal tissues (Hobson, 1999). Stable isotope analyses are safe since they are non-radioactive, and they can reflect the long-term feeding behavior of animals, which make them useful natural tracers (Hood-Nowotny and Knols, 2007;Peterson and Fry, 1987;Schmidt et al, 1999).…”