Skip to main content
ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #190823
Title: PINK BOLLWORM LARVAL FEEDING ON ‘NUCOTN 33B®’ COTTON BOLLS: EFFECTS ON LARVAL DEVELOPMENT, MORTALITY, AND PUPATION AND TOLERANCE TO CRY1AC TOXIN IN COTTON BOLLS, POLLEN, AND ARTIFICIAL DIET BIOASSAYS

Author
item Henneberry, Thomas
item Jech, Lynn
item Maurer, Jamie

Submitted to: Southwestern Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2006
Publication Date: 9/1/2006
Citation: Henneberry, T.J., Jech, L.J., Maurer, J.C. 2006. Effects of pink bollworm larval feeding on ‘NuCOTN 33B®’ cotton bolls and pollen and tolerance to Cry1Ac in artificial diet bioassays. Southwestern Entomologist Vol 31(3): 169-185.

Interpretive Summary: Transgenic cottons (BT) have been grown commercially in Arizona since 1996. We conducted laboratory studies from 2001 to 2005 to determine the effect of pink bollworm (PBW) larval feeding periods on NuCOTN 33B® bolls on development, mortality, pupation, and tolerance to the Cry1Ac toxin. Initially, higher larval mortality occurred and more days were required for pupal development following four or seven day feeding periods on NuCOTN 33B® bolls compared with similar feeding periods on Delta and Pineland (DPL) 5415 non-toxin containing bolls. Mortality and larval development time decreased as the number of larval feeding generations increased suggesting adaptation to the toxin in bolls. Some larvae of a PBW strain [BG®(4)] developed by feeding for 35 of 40 generations for four days in each generation on NuCOTN 33B® bolls survived to larval maturity on NuCOTN33B® pollen for 20 days or on 10 ug/ml Cry1Ac-fortified artificial diets for 21 days. No survival of BG(4) strain larvae occurred on NuCOTN 33B® bolls for more than seven days. The 10 ug/ml Cry1Ac concentration has been determined as the discriminating dose for PBW resistance in the laboratory. No larvae of a DPL 5415 PBW control or a BG®(7) strain developed to maturity when feeding for similar periods of time on NuCOTN 33B® pollen, bolls, or Cry1Ac-fortified diets. Moth emergence from the BG®(4) strain surviving pupae ranged from 42 to 100%, and mating occurred, but oviposition was reduced.

Technical Abstract: Transgenic cottons (Bt), Gossypium hirsutum L., have been grown commercially in Arizona since 1996. We conducted laboratory studies from 2001 to 2005 to determine the effect of (PBW), Pectinophora gossypiella (Saunders), larval feeding periods on NuCOTN 33B® bolls on development, mortality, pupation, and tolerance to the Cry1Ac toxin. Initially, higher larval mortality occurred and more days were required for pupal development following four or seven day feeding periods on NuCOTN 33B® bolls compared with similar feeding periods on Delta and Pineland (DPL) 5415 non-toxin containing bolls. Mortality and larval development time decreased as the number of larval feeding generations increased suggesting adaptation to the toxin in bolls. Some larvae of a PBW strain [BG®(4)] developed by feeding for 35 of 40 generations for four days in each generation on NuCOTN 33B® bolls survived to larval maturity on NuCOTN33B® pollen for 20 days or on 10 ug/ml Cry1Ac-fortified artificial diets for 21 days. No survival of BG(4) strain larvae occurred on NuCOTN 33B® bolls for more than seven days. The 10 ug/ml Cry1Ac concentration has been determined as the discriminating dose for PBW resistance in the laboratory. No larvae of a DPL 5415 PBW control or a BG®(7) strain developed to maturity when feeding for similar periods of time on NuCOTN 33B® pollen, bolls, or Cry1Ac-fortified diets. Moth emergence from the BG®(4) strain surviving pupae ranged from 42 to 100%, and mating occurred, but oviposition was reduced.