Premium
Clear advantages for fall armyworm larvae from feeding on maize relative to its ancestor Balsas teosinte may not be reflected in their mother's host choice
Author(s) -
Bernal Julio S.,
Melancon Joseph E.,
ZhuSalzman Keyan
Publication year - 2015
Publication title -
entomologia experimentalis et applicata
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.765
H-Index - 83
eISSN - 1570-7458
pISSN - 0013-8703
DOI - 10.1111/eea.12299
Subject(s) - biology , host (biology) , larva , predation , fall armyworm , crop , domestication , parasitism , zea mays , herbivore , botany , poaceae , agronomy , spodoptera , ecology , gene , genetics , recombinant dna
Consistent with an increasing number of comparisons between crop plants and their wild ancestors, a previous study showed that in the field, maize [ Z ea mays ssp. mays L. ( P oaceae)] suffers more herbi‐vory by larvae of S podoptera frugiperda JE S mith ( L epidoptera: N octuidae) than its ancestor B alsas teosinte ( Z ea mays ssp. parviglumis I ltis & D oebley). This study addressed plausible causes of the differing herbivory levels between maize and B alsas teosinte, specifically whether host plant selection by adult females is biased for either host plant depending on larval performance—i.e., the preference‐performance hypothesis—or risk of mortality by parasitoids and predators—i.e., the natural enemy‐free space hypothesis. Field observations showed that performance of S . frugiperda larvae was superior on maize compared with B alsas teosinte, a result partially explainable by the greater toughness of teosinte compared with maize tissue, but not by a difference in inhibition of protein digestion by larvae. Additional field observations showed that the mortality risk of S . frugiperda larvae is higher on B alsas teosinte, as indicated by higher parasitism (ca. four‐fold) and predation (ca. three‐fold) rates on the teosinte compared with maize. However, laboratory observations showed that S . frugiperda females did not discriminate between maize and B alsas teosinte for oviposition. Overall, the study's results were consistent with prior observations that direct and indirect defenses of maize against S . frugiperda larvae were weakened with domestication. In contrast, the results were inconsistent with predictions of the preference‐performance and natural enemy‐free space hypotheses, because selection of maize or B alsas teosinte plants by S . frugiperda females was independent of their offspring's performance and risk of mortality by natural enemies. On the one hand, this study's results partially explained differing herbivory levels between a crop and its wild ancestor, and on the other hand they suggested that host selection by S . frugiperda may be mediated by larval dispersal behavior and host choices.