Hybrid poplar clones with Populus maximowiczii parentage demonstrate postoviposition antibiosis to Cryptorhynchus lapathi (Coleoptera: Curculionidae).
Damage caused by the poplar-and-willow borer, Cryptorhynchus lapathi (L.) (Coleoptera: Curculionidae), is reported to vary among hybrid poplar clones. We evaluated oviposition preferences and larval success in four hybrid poplars on potted and field-planted trees. Oviposition occurred somewhat less frequently and abundantly on two clones with Populus maximowiczii Henry parentage in field-planted and potted trees, and significantly fewer larvae survived to adulthood on those clones. No adults emerged from field-planted NM 6 (Populus nigra L. x P. maximowiczii) and four emerged from TM 256-28 (Populus trichocarpa Torrey & Gray x P. maximowiczii) on which male-female pairs of C. lapathi had been caged. In contrast, 50 and 140 adults emerged over the same 2-yr period from two susceptible clones (n = 20), TD 52-226 (P. trichocarpa x Populus deltoides Bartram ex Marshall) and TN 302-9 (P. trichocarpa x P. nigra), respectively. Thus, resistance expressed by clones with P. maximowiczii parentage partially involves decreased levels of oviposition, but more significantly, antibiosis in resistant clones prevents the development of larvae, probably in early spring.
Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5C 3E6, Canada.
Cynthia L
CL
Broberg
John H
JH
Borden
D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D003433:Crosses, Genetic; D010058:Oviposition; D010063:Ovum; D032107:Populus / Q000235:genetics* / Q000502:physiology*