Chapter IV
Prey Sensitization, Learning and Memory in Reduviids: Implications in
Biological Control
4.1. Introduction
Sensitization is an increasing response to a stimulus presented repeatedly while habituation denotes a failure of response to the stimulus (Staddon, 1988). The process of sensitization has enormous adaptive value. When a prey escapes from the clutches of a predator as a result of exhibiting a response, it gets sensitized. If and when a second attempt at capture is initiated by the predator, the prey might give a heightened response that would facilitate its escape. This is known as anti-predator response and when the prey is alerted to the presence of a predator when it comes across visual or chemical cues, it lays low and …show more content…
learning) should be better able to deal with variability in predation pressure. In a study on variation in the plasticity of tadpole’s response to different predators, Richardson (2001) found that tadpoles reduced their activity in a general response to any predator, despite having no history of encountering some of the test predators in their native habitats. This finding supports the claim that in threat sensitive predator avoidance hypothesis, the prey undergoes behavioural modifications in a manner that attracts very little attention to them. Thus it can be said that the prey is sensitized to the predator as a result of an encounter. The same concept can be applied to the predator as well in instances such as biological pest control when the predator is expected to kill the prey.
The advantage of familiarity provided by a previous encounter aids in decreasing the time taken for the predator to overpower the prey. Reduviids being indiscriminate killers are known to kill even when they are satiated. If they are exposed to the prey once, during which they are given an opportunity to size up their opponents, their rate at successfully killing the prey would be higher. Behaviour and behavioural change plays a pivotal role in determining how the chances of survival are increased as a result of sensitization, be it prey or …show more content…
But, the first generation of laboratory moulted adults preferred the injured but moving and writhing prey. This can be due to their less aggressive lifestyle wherein food was provided to them and they were not required to spend time searching for food to hunt them down. On the whole the laboratory reared individuals were less aggressive and preferred comparatively smaller and less violent prey. They were reluctant to take on a bigger or active prey and their readiness to take risks was lower (Fig. 14, 15).
c) Influence of Type of Feed on Predatory Behaviour
This procedure clearly showed the impact the type of feed can have on the aggressiveness of the predators. The individuals fed with the artificial diet were unable to predate on prey much smaller than them and were not good at chasing and pinning down prey either. Adult A. sexguttata were unable to capture camponotine ants and were injured in the encounter. Though the other batch were also laboratory reared and had very less encounters with predating in the natural environment, they found it easier to spot, chase and capture prey. This is a direct result of them being fed with live prey (Fig. 16, 17).
d) Role of Sensitization by Selective Exposure to
Prey Sensitization, Learning and Memory in Reduviids: Implications in
Biological Control
4.1. Introduction
Sensitization is an increasing response to a stimulus presented repeatedly while habituation denotes a failure of response to the stimulus (Staddon, 1988). The process of sensitization has enormous adaptive value. When a prey escapes from the clutches of a predator as a result of exhibiting a response, it gets sensitized. If and when a second attempt at capture is initiated by the predator, the prey might give a heightened response that would facilitate its escape. This is known as anti-predator response and when the prey is alerted to the presence of a predator when it comes across visual or chemical cues, it lays low and …show more content…
learning) should be better able to deal with variability in predation pressure. In a study on variation in the plasticity of tadpole’s response to different predators, Richardson (2001) found that tadpoles reduced their activity in a general response to any predator, despite having no history of encountering some of the test predators in their native habitats. This finding supports the claim that in threat sensitive predator avoidance hypothesis, the prey undergoes behavioural modifications in a manner that attracts very little attention to them. Thus it can be said that the prey is sensitized to the predator as a result of an encounter. The same concept can be applied to the predator as well in instances such as biological pest control when the predator is expected to kill the prey.
The advantage of familiarity provided by a previous encounter aids in decreasing the time taken for the predator to overpower the prey. Reduviids being indiscriminate killers are known to kill even when they are satiated. If they are exposed to the prey once, during which they are given an opportunity to size up their opponents, their rate at successfully killing the prey would be higher. Behaviour and behavioural change plays a pivotal role in determining how the chances of survival are increased as a result of sensitization, be it prey or …show more content…
But, the first generation of laboratory moulted adults preferred the injured but moving and writhing prey. This can be due to their less aggressive lifestyle wherein food was provided to them and they were not required to spend time searching for food to hunt them down. On the whole the laboratory reared individuals were less aggressive and preferred comparatively smaller and less violent prey. They were reluctant to take on a bigger or active prey and their readiness to take risks was lower (Fig. 14, 15).
c) Influence of Type of Feed on Predatory Behaviour
This procedure clearly showed the impact the type of feed can have on the aggressiveness of the predators. The individuals fed with the artificial diet were unable to predate on prey much smaller than them and were not good at chasing and pinning down prey either. Adult A. sexguttata were unable to capture camponotine ants and were injured in the encounter. Though the other batch were also laboratory reared and had very less encounters with predating in the natural environment, they found it easier to spot, chase and capture prey. This is a direct result of them being fed with live prey (Fig. 16, 17).
d) Role of Sensitization by Selective Exposure to