Seven accessions or varieties of cultivated pea Pisum sativum L. varying in surface waxbloom characteristics were grown in replicated small plots (1 m2) for two seasons to monitor natural infestations of insect herbivores and abundance of predatory insects. Waxbloom was quantified on the basis of the amount of waxes extractable from leaf surfaces, densities of wax crystals visible with scanning electron microscopy, and visual appearance. During each season, pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphidae), densities per plant were significantly lower on peas with reduced surface waxbloom as compared with peas with standard or ‘normal’ surface waxbloom. This difference was greatest between two near-isolines of peas differing in expression of a mutation that reduces surface waxes. Although reduced-waxbloom plants had lower end-of-season above ground biomass and vine lengths, including these variables as covariates did not affect the significance of the waxbloom effects on aphid densities. Damage to leaves and stipules by the pea leaf weevil Sitona lineatus (L.) (Coleoptera: Curculionidae) was greater on reduced-waxbloom peas than normal-waxbloom peas. Thus, as occurs in other crops, reduced waxbloom in peas is associated with lower natural infestations of an aphid, but also with increased susceptibility to a folivorous beetle. Populations of predatory coccinellids did not differ consistently between years on reduced-waxbloom versus normal-waxbloom peas, failing to support a hypothesis that predator populations are higher on reduced waxbloom peas, contributing to the lower aphid populations on these plants.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.