Preference-performance hypothesis and host oviposition selection of Diabrotica speciosa: aboveground female avoids belowground conspecific larvae in maize

摘要: According to the theory of optimal foraging and preference–performance hypothesis, herbivores usually select plant hosts that benefit themselves or their offspring. We investigated the hypothesis that gravid females of the cucurbit beetle Diabrotica speciosa use volatiles derived from non-infested maize plants and herbivore-infested plants under attack by their conspecific immatures and adults in selecting a host for oviposition. The response of D. speciosa females to volatiles was quantified for the following treatments: (i) non-infested plants; (ii) plants infested by larvae (root-infested); (iii) plants infested by adults (leaf-infested); and (iv) plants infested by larvae and adults (leaf + root-infested). We also assessed if females were able to identify conditions of competition and host adequacy for offspring by means of chemical cues emitted by these plants. The results indicated that the presence of D. speciosa …