Prey or host searching behavior that leads to a sigmoid functional response in invertebrate predators and parasitoids

Abstract

Summary Invertebrate predators and parasitoids have long been characterized as having a hyperbolic (Type 2) functional response. Modifications were made to Holling's sand paper disc experiment which consisted of limiting the initial period of search during which a host must be contacted. Failure to contact a host during this initial period causes the predator to emigrate from the search area. The modification generated a sigmoid (Type 3) functional response. This response resulted from the low probability of encountering a host during the initial period of search at low host densities in the time allotted. A limited period of search has been found in several insect parasitoids. Such a strategy would minimize the time (energy) spent per offspring produced by minimizing the time invested in searching microhabitats in which hosts are scarce or absent.

Predation on Australian soldier fly,Inopus rubriceps(Diptera: Stratiomyidae), in pasture

“…2). (Holling 1959(Holling , 1966, although other invertebrates have shDwn responses which gave the sigmoid curve (Hassell 1978, Luck et al 1979. BehaviDur such as prolonged resting between captures at low prey denslities can result in a sigmoidal curve flor invertelbrate predators.…”

Plankton blooms and patchiness generated by heterogeneous physical environments

“…If a predator is hunting in an area with low prey density, it may migrate into another area if it is not successful in finding food for some time (Anderson et al, 2012). This behavior can be modeled by a sigmoid functional response (Luck et al, 1979;Real, 1977). A turbulent environment would disturb the predator, making it harder or even unnecessary to behave like this because the turbulent medium force the plankton to some random motion.…”

Effect of prey density on functional and reproductive responses of the predatory mitePhytoseiulus longipes(Acari: Phytoseiidae)

“…1978), some degree of prey specificity and adaptation to prey habitat (Huffaker et al, 1976), including spider mite webs , Sabelis, 1981, small handling time in relation to the life span of the predators and some degree of interference among predators in patches of low prey densities (Hassell and May, 1973), collectively play parts in stabilizing the predator-prey systems. Van Lenteren and Bakker (1978), and Luck et al (1979) emphasized that predators which spent less time in places with low prey densities and vice versa, increase their searching efficiency. Furthermore, they assumed that predators evolve a searching strategy in which they spend minimum time and energy in such parts of the habitat with low prey densities.…”