The effect of prey size and prey density on the functional response, survival, growth and development of a predatory pentatomid bug, Podisus maculiventris say

Abstract

Summary Two experiments on the nymphal predation of Podisus maculiventris were conducted using Spodoptera litura larvae as prey. First experiment: The predator nymphs divided into three groups were reared individually from second instar to adult in a small vessel. Each nymph in the groups 1, 2 and 3 was allowed to attack the serially growing larvae (these were supplied at the rate of one per day) from 3‐, 5‐ and 7‐day old after hatching, respectively. The first prey used for the group 1 was so small that it was not only insufficient to satiate the predator but also was difficult to be searched out. But these disadvantages were soon recuperated due to the rapid growth of the prey and all nymphs could survive to adults. The survival rate of third and fourth instar nymphs in the group 3 was severely affected by vigorous counterattack of older prey larvae. Second experiment: The predator nymphs were individually reared either in a small vessel or in a large one at various rates of food supply (the prey larvae of 7‐day old were used). The functional response curves obtained for each instar of the predator took a saturation type within a certain range of the prey density. The saturation level specific to each instar was generally higher for the predator reared in the large vessel than in the small one. The functional response of fourth and fifth instar nymphs was accelerated at a high prey density, viz. 16 larvae per vessel. Even at the low rate of food supply, viz. one larva per day per predator, the predator nymphs could survive to adults, but the size of resultant adults were abnormally small.

Dynamics of handling time and functional response by larvae of Chrysomya albiceps (Dipt., Calliphoridae) on different prey species

“…It spends more time handling third instar larvae than first and second instar larvae. This result can be confirmed by several findings which indicate that the largest prey required a handling time longer than that for the smallest one ( Mukerji and Leroux , 1969; Hokyo and Kawauchi , 1975; De Clercq et al., 1998, 2000). However, the handling time recorded for third instar larvae showed a higher variability compared with the other prey.…”

Effect of prey density on behaviour and development of the predatory mosquito, Toxorhynchites towadensis

“…The larval mortality may have been due to starvation caused by a low prey encounter rate, especially during the first instar. In other predatory insects such as the predaceous bug, Podisus maculiventris (Hokyo & Kawauchi, 1975) and the ladybird, Propyleajaponica (Kawauchi, 1979), low prey density increases larval mortality. Pupal mortality may have been due to disturbance of pupation by prey individuals remaining alive in the container; larvae of A. albopictus often pecked the predatory larvae (Yasuda & Mitsui, 1992).…”

“…Several factors, such as predator and prey density, searching efficiency, and activity of prey, affect the rate of prey encounter (Carter & Dixon, 1982;Pandey et al, 1984;Hubbard et al, 1988;Sherratt & Tikasingh, 1989). The prey encounter rate may influence the development and survival of the predator (Hokyo & Kawauchi, 1975;Baumgaertner et al, 1981;Matsura & Morooka, 1983;Zheng etal., 1993a, b). In some sitand-wait arthropod predators, the feeding behaviour as well as the metabolic rate is also influenced by the amount of prey consumed (Matsura, 1981;Tanaka & Ito, 1982).…”

Food extraction by the males of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) from cotton leafworm larvae

“…When nymphs or adults of P. maculiventris and P. sagitta were submitted to higher densities of prey under laboratory conditions, they attacked and preyed more individuals than they needed to meet their eating needs (De Clercq and Degheele, 1994). Hokyo and Kawauchi (1975) reported that the quantity of larvae of Spodoptera litura (Fabricius) consumed by P. maculiventris was greater as the food offer increased. Predators are more likely to find their prey more frequently in higher densities of prey than in lower densities, which stimulates greater efforts in attack, and thus neglects the hunger effect in preying (Holling, 1966).…”

“…Studies discussing the existing relation between the number of preys captured by the predators compared to the density of preys, known as functional response (Holling, 1966;Mills, 1982), are important for a better understanding of the relation between the predator and prey. The behavior of predators of the genus Podisus in relation to their preys have been studied by Tostowaryk (1972) and Hokyo and Kawauchi (1975); however, little is known about the predatory behavior of P. nigrispinus when submitted to different densities of prey. In light of the importance of P. nigrispinus, it is surprising how little attention has been paid to predatory capacity of P. nigrispinus and its impact on cotton leafworm in Brazil.…”