W. Pett

Effects of dietary transgenic Bt corn pollen on larvae of Apis mellifera and Galleria mellonella

SUMMARY The effects of dietary transgenic Bt corn pollen on 4–5–day-old honey bee worker larvae were examined. We measured larval and pupal mortalities, pupal weight, and haemolymph protein concentration of newly emerged adults after they were fed (as larvae) various pollens (mixed bee pollen, non-transgenic corn pollen, Cry1A(b) or Cry1F corn pollen). There were no significant differences in all the parameters tested between larvae fed transgenic Bt corn pollen Cry1 A(b) or Cry1 F and non-transgenic corn pollen. We also evaluated Bt corn pollen as a potential control for wax moth larvae in a laboratory study. We fed first instar wax moth larvae three types of pollen: non-transgenic corn pollen, Cry1 A(b) corn pollen, and Cry1F corn pollen. We found that the mortality of larvae fed Cry1 F corn pollen was significantly greater than the mortality of larvae fed Cry1 A(b) corn pollen or non-transgenic corn pollen (P < 0.05). In each trial Cry1 F fed larvae showed 100% mortality. Our studies suggest that transgenic Bt corn pollen does not pose a threat to honey bee larval development and has the potential to serve as an alternative control for wax moth.

Evaluation of Potato Tuber Moth (Lepidoptera: Gelechiidae) Resistance in Tubers of Bt-cry5 Transgenic Potato Lines

Abstract The potato tuber moth, Phthorimaea operculella (Zeller), in tropical and subtropical countries, is the most destructive pest of potato, Solanum tuberosum L. The larvae attack foliage and tubers in the field and in storage. The purpose of this study was to evaluate the efficacy of a Bt-cry5 transgene to control the potato tuber moth in tuber tissues. Tuber bioassays using stored (11-12 mo old) and newly harvested tubers of Bt-cry5-Lemhi Russet and Bt-cry5-Atlantic potato lines showed up to 100% mortality of 1st instars. Mortality was lowest in the newly harvested tubers of Bt-cry5-Atlantic lines (47.1–67.6%). Potato tuber moth mortality was 100% in the Bt-cry5-Spunta lines that were transformed with Bt-cry5 gene controlled by the CaMV 35S promoter (pBIML5 vector) and in 2 of 3 lines transformed with Bt-cry5 gene controlled by the Gelvin super promoter (pBIML1vector). The transgenic Spunta lines expressing Bt-cry5 controlled by the patatin promoter (pBMIL2 vector) showed the lowest tuber moth mortality (25.6 and 31.1%). The Bt-cry5 transgenic lines with high tuber expression of B. thuringiensis have value in an integrated pest management system to control potato tuber moth.

Field and Semifield Evaluation of Impacts of Transgenic Canola Pollen on Survival and Development of Worker Honey Bees

Abstract A 2-yr field trial (2001 and 2002) and 1-yr semifield trial (2002) were conducted to evaluate the effect of transgenic herbicide (glyphosate)-tolerant canola Brassica napus L. pollen on larval and adult honey bee, Apis mellifera L., workers. In the field trial, colonies of honey bees were moved to transgenic or nontransgenic canola fields (each at least 40 hectares) during bloom and then sampled for larval survival and adult recovery, pupal weight, and hemolymph protein concentrations. No differences in larval survival, adult recovery, and pupal weight were detected between colonies placed in nontransgenic canola fields and those in transgenic canola fields. Colonies placed in the transgenic canola fields in the 2002 field experiment showed significantly higher hemolymph protein in newly emerged bees compared with those placed in nontransgenic canola field; however, this difference was not detected in the 2001 field experiment. In the semifield trial, bee larvae were artificially fed with bee-collected transgenic and nontransgenic canola pollen and returned to their original colonies. Larval survival, pupal survival, pupal weight, and hemolymph protein concentration of newly emerged adults were measured. There were no significant differences in any of the parameters measured between larvae that were fed transgenic canola pollen and those fed nontransgenic corn pollen. Results from this study suggest that transgenic canola pollen does not have adverse effects on honey bee development and that the use of transgenic canola dose not pose any threat to honey bees.

Evaluations of Transgenic Potatoes for Resistance to Potato Tuberworm in the Laboratory and Field

The potato variety ‘Spunta’ was previously transformed to constitutively express the cry1Ia1 gene from Bacillus thuringiensis from which three transgenic lines (SpuntaG2, SpuntaG3 and Spunta6a3) were chosen to evaluate for resistance to potato tuberworm (Phthorimaea operculella Zeller). Because potato tuberworm is becoming a serious pest in the Pacific Northwest of the United States, ‘SpuntaG2’, ‘SpuntaG3’ and ‘Spunta6a3’ were evaluated in Washington State through laboratory and field experiments. In the laboratory, both choice and no-choice experiments demonstrated that the transgenic ‘Spunta’ lines were completely resistant (100% mortality) to potato tuberworm. Potato tuberworm resistance was further supported by choice, field-cage studies in which the transgenic ‘Spunta’ lines harbored no potato tuberworm larvae at any sampling date while the controls were heavily infested (averaging 6.4 to as many 17.0 larvae per stem). These results indicate that the cry1Ia1 gene could be an effective component of potato tuberworm management in the Pacific Northwest as well as the international venues where it has already been proven effective.ResumenSe transformó previamente a la variedad de papa “Spunta” para que expresara constitutivamente el gen cry1Ia1 de Bacillus thuringiensis, de la cual se seleccionaron tres líneas transgénicas (SpuntaG2, SpuntaG3, y Spunta6a3) para evaluarles su resistencia a la palomilla de la papa (Phthorimaea operculella Zeller). Considerando que la palomilla de la papa se está convirtiendo en una plaga seria en el Pacífico Noroeste de los Estados Unidos, “SpuntaG2”, “SpuntaG3”, y “Spunta6a3” se evaluaron en el Estado de Washington en experimentos de laboratorio y campo. En el laboratorio, ambos, experimentos seleccionados y no seleccionados, demostraron que las líneas transgénicas de Spunta fueron completamente resistentes (100% de mortalidad) a la palomilla de la papa. La resistencia fue posteriormente respaldada por estudios de selección, en jaulas de campo, en donde las líneas transgénicas de Spunta no mantuvieron a las larvas de la palomilla en ninguna de las fechas de muestreo, mientras que los testigos estuvieron fuertemente infestados (promediando de 6.4 a tanto como 17.0 larvas por tallo). Estos resultados indican que el gen cry1Ia1 pudiera ser un componente efectivo en el manejo de la palomilla de la papa en el Pacífico Noroeste, así como a nivel internacional donde ya se ha probado que es efectivo.

Segregation and Efficacy of the cry1Ia1 Gene for Control of Potato Tuberworm in Four Populations of Cultivated Potato

ABSTRACT The potato (Solanum tuberosum L.) cultivar ‘SpuntaG2’ contains a single copy of the Bacillus thuringiensis (Bt) cry1Ia1 gene and controls potato tuberworm (Phthorimaea operculella Zeller, Lepidoptera: Gelechiidae). Two potato cultivars and two breeding lines were crossed with SpuntaG2 creating four populations used to study cry1Ia1 segregation and efficacy. The cry1Ia1 gene segregated in each of the four populations with a 1:1 ratio. All progeny that were polymerase chain reaction positive for the cry1Ia1 gene had no surviving larvae and no leaf mining in detached leaf assays after 72 h. These results support previous evidence that SpuntaG2 carries a single copy of the cry1Ia1 gene and that transmission of the transgene from parent to progeny is not restricted and follows expected Mendelian segregation ratios. Based on detached leaf assays, the efficacy of the cry1Ia1 gene is retained through sexual transmission. If the SpuntaG2 cry1Ia1 insertion event is deregulated for commercial use, SpuntaG2 could be used for conventional breeding and the progeny carrying the SpuntaG2 event would also be available for commercial use.