Intra- versus inter-specific interactions of Μacrolophus pygmaeus and Nesidiocoris tenuis foraging on an aphid population
Abstract: The nature of antagonistic/synergistic interactions among predators sharing common prey patches has been widely reported to play a major role in biological control. This study focuses on the effects of prey availability on the predation rate of two predators: Μacrolophus pygmaeus and Nesidiocoris tenuis (Hemiptera: Miridae) when foraging alone or together under different prey density levels. Intraspecific and interspecific interactions were tested by introducing either a conspecific or heterospecific pair into a dish with an eggplant leaf where 2nd instar Myzus persicae nymphs were present as prey. Prey densities of 4, 12, 20, 24, 32 and 40 were used and consumption was recorded after 24 h. Functional responses of each predator species were evaluated. We also simultaneously employed both the multiplicative and substitutive design to test the independent and combined effects of the two predatory species. According to the outcomes, both predators exhibited a Type II functional response with Μ. pygmaeus satiated at comparatively lower prey density than N. tenuis. Emergent multiple predator effects were largely absent in this system, since the outcomes were consistent with the expected combined effects of these two predators. This is likely due to partial spatial separation of these predators when foraging in a common habitat.