Preliminary evaluation of sugars from flowering plants as food resourcesfor Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)in an olive agroecosystem

Abstract: Natural enemies play a major role in sustainable olive production through their abilityto regulate populations of insect pests. Many depend as adults on carbohydrate-rich food as themain source of energy for longevity, fecundity, and mobility. Conservation of naturally occurringsugar sources in agricultural fields, such as suitable flowering plants, may enhance beneficialpopulations, thereby leading to improved pest control. Besides three dominant sugars (sucrose,glucose, and fructose), nectar can contain various other sugars, sometimes in significantconcentrations. Also, insect species can vary considerably with respect to the spectrum of nectarsugarsthey use. The goal of this study is to evaluate the potential of a range of native plantspecies from the olive agroecosystem to provide nectar resources for Chrysoperla carnea(Stephens), a major predator of important pests from this ecosystem. We examined the effect often naturally occurring sugars on reproduction and adult survival in the laboratory. The sugarcomposition of the nectar in flowers was determined by high performance anion exchangechromatography with pulsed amperometric detection (HPAEC-PAD) analysis. We discuss theresults in the context of selecting floral resources to maximize conservation biological control inthe olive grove ecosystem.