We studied larval dispersal behavior of two rice stem borers, Scirpophaga incertulas (Walker) and Chilo suppressalis (Walker), to evaluate the potential of seed mixtures for resistance management in B. thuringiensis (Bt) rice. Both species showed extensive movement among plants (or “hills”) in plots of transplanted rice, during the course of larval development. On rice plants at the vegetative stage, almost all S. incertulas larvae dispersed on the day of eclosion. On plants at booting stage, most S. incertulas bored into hills on which egg masses were placed (referred to as the “release hill”). Almost all neonate C. suppressalis also bored into the release hill, at both vegetative and booting stages. At both rice growth stages, most larvae of both species dispersed to new hills between 7 and 18 d after eclosion. Both S. incertulas and C. suppressalis moved among tillers within the release hill, as indicated by an increase in dispersion among tillers over time. The distance and direction of dispersal of ballooning S. incertulas larvae was influenced by wind speed and direction. Larval recovery within plots generally declined rapidly over the first 5 d after egg hatch and then more slowly thereafter. Because many S. incertulas and C. suppressalis larvae move among tillers within hills and among hills within plots, many larvae in plots planted to seed mixtures will consume tissue from both Bt and non-Bt plants. This behavior will reduce the cumulative dose of toxin ingested and can accelerate the evolution of resistance.
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.