title: Characterization of resistance to adult spittlebugs (Hemiptera: Cercopidae) in Brachiaria spp.
abstract: Nymphs and adults of several spittlebug (Hemiptera: Cercopidae) species are key pests of forage brachiariagrasses (Brachiaria spp.) in tropical America. To support current breeding programs, a series of experiments aimed at characterizing the mechanisms of resistance to adult feeding damage were carried out. Five genotypes were used: two susceptible checks (CIAT 0606 and CIAT 0654) and three nymph-resistant genotypes (CIAT 36087, CIAT 6294, and SX01NO/0102). Test insects were Aeneolamia varia (F.), A. reducta (Lallemand), and Zulia carbonaria (Lallemand). The nymph-resistant genotypes showed tolerance to all spittlebug species tested. Tolerance in these genotypes can be classified as only moderate given the extent of losses (60-80%) caused by both female and male adults. None of the nymph-resistant genotypes had antibiotic effects on adults feeding on foliage. The results also indicated that antixenosis for feeding is not a plausible explanation for lower damage scores and less biomass losses in resistant genotypes. The fact that adult longevity (usually 8 d) was not affected when the adults were forced to feed on roots of a genotype with strong antibiotic resistance to nymphs is regarded as additional evidence that resistances to nymphs and to adults in Brachiaria are largely independent.
authors.affiliation: Centro Internacional de Agricultura Tropical, CIAT, Apartado Aéreo 6713, Cali, Colombia.
authors.forename: Lina M
authors.initials: LM
authors.lastname: Aguirre
authors.forename: César
authors.initials: C
authors.lastname: Cardona
authors.forename: John W
authors.initials: JW
authors.lastname: Miles
authors.forename: Guillermo
authors.initials: G
authors.lastname: Sotelo
mesh_terms: D000818:Animals; D000898:Antibiosis; D035201:Brachiaria / Q000235:genetics / Q000502:physiology*; D005260:Female; D005838:Genotype; D006430:Hemiptera / Q000254:growth & development / Q000502:physiology*; D060434:Herbivory; D008297:Male; D009758:Nymph / Q000254:growth & development / Q000502:physiology; D010572:Pest Control, Biological; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D013045:Species Specificity