Effect of plant nitrogen and water status on the foraging behavior and fitness of an omnivorous arthropod.

Peng Han,Philippe Bearez,Anne‐Violette Lavoir,Stéphane Adamowicz,Nicolas Desneux,Eric Wajnberg,Yongcheng Dong

doi:10.1002/ece3.1788

Abstract

Omnivorous arthropods make dietary choices according to the environment in which they forage, mainly availability/quality of plant and/or prey resources. Such decisions and their subsequent impacts on life‐history traits may be affected by the availability of nutrients and water to plants, that is, through bottom‐up forces. By setting up arenas for feeding behavior observation as well as glasshouse cages for plant preference assessment, we studied effects of the presence of prey (Lepidoptera eggs) and nitrogen/water availability to host tomato plants on the foraging behavior and life‐history traits in the omnivorous predator Macrolophus pygmaeus (Heteroptera: Miridae). In the absence of prey, the predator fed equally on the plants treated with various levels of nitrogen and water. In the presence of prey, however, the feeding rate on plants decreased when the plant received low water input. The feeding rate on prey was positively correlated with feeding rate on plants; that is, prey feeding increased with plant feeding when the plants received high water input. Moreover, plants receiving high water input attracted more M. pygmaeus adults compared with those receiving low water input. For M. pygmaeus fitness, the presence of prey enhanced its fertility and longevity, but the longevity decreased when plants received low compared with high water input. In conclusion, the omnivorous predator may be obliged to feed on plants to obtain water, and plant water status may be a limiting factor for the foraging behavior and fitness of the omnivorous predator.

Highlights

Omnivores, that is, organisms feeding on two or more trophic levels, are widespread across many animal taxa
Ecology and Evolution published by John Wiley & Sons Ltd
Our data demonstrated that plants subjected to varying nitrogen and water inputs may trigger bottom-up effects on M. pygmaeus foraging behavior as well as its fitness

Summary

Introduction

That is, organisms feeding on two or more trophic levels, are widespread across many animal taxa. Such a feeding habit may partly explain the fact that food webs are highly interconnected and complex. Omnivory has been thought to play important roles in shaping the natural community structure and dynamics (Naranjo and Gibson 1996; McCann et al 1998; Coll and Guershon 2002; Eubanks 2005; Thompson et al 2007; Chubaty et al 2014), and the arthropod communities (McMurtry and Croft 1997; Coll 1998; Eubanks and Denno 2000; Symondson et al 2002; Eubanks et al 2003). Foraging has been considered one of the most important aspects in behavioral ecology study in omnivorous arthropods.

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