Observations on Wallrothiella arceuthobii, a fungus parasite of dwarf mistletoes

1969 ◽  
Vol 47 (9) ◽  
pp. 1359-1365 ◽  
Author(s):  
Job Kuijt
Keyword(s):  
Life Cycle ◽  
North America ◽  
Unknown Function ◽  
Western North America ◽  
Sectioned Material ◽  
Young Embryo ◽  
Spore Dissemination

Certain aspects of the life cycle of Wallrothiella arceuthobii are detailed from field and microscopical observations. Infected fruits of the host often continue to develop for several weeks after spore dissemination. Sectioned material shows that the fungus tends to avoid the young embryo and endosperm, yet attacks other adjacent mistletoe tissues. Perithecial shape varies considerably between eastern and western North America. Some western specimens show periostiolar locules of unknown function. The genus may be related to Coryneliaceae.

BIONOMICS OF ENOCLERUS BARRI (COLEOPTERA: CLERIDAE)

1969 ◽  
Vol 101 (4) ◽  
pp. 382-386 ◽  
Author(s):  
Richard E. Rice
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
North America ◽  
Sex Ratio ◽  
Rocky Mountain ◽  
Mountain Region ◽  
Western North America ◽  
Adult Females ◽  
Rocky Mountain Region ◽  
Life Cycle Stages

AbstractEnoclerus barri Knull occurs in western North America from British Columbia south to Mexico and throughout the Rocky Mountain region. Adults were collected at Grass Valley, Calif., from May to September at traps baited with beetle attractants. Collections occurred at temperatures ranging from 22.5° to 31 °C; the sex ratio of trapped beetles was 4.5 females to 1 male. Duration of life cycle stages at 24 ± 2 °C were: egg, 9 days; larva, first iastar, 14 days; second instar, 12 days; third instar feeding stage, 14 days. All larvae reared to third instar failed to pupate in the laboratory. Adult females of unknown age when collected lived from 10 to 131 days and produced an average of 389 eggs per female. Enoclerus barri utilized six species of Scolytidae as hosts in the laboratory.

LOCAL AND REGIONAL RESISTANCE TO FENVALERATE IN PSYLLA PYRICOLA FOERSTER (HOMOPTERA: PSYLLIDAE) IN WESTERN NORTH AMERICA

1989 ◽  
Vol 121 (2) ◽  
pp. 121-129 ◽  
Author(s):  
B.A. Croft ◽  
E.C. Burts ◽  
H.E. van de Baan ◽  
P.H. Westigard ◽  
H. Riedl
Keyword(s):  
Life Cycle ◽  
North America ◽  
Pyrethroid Resistance ◽  
Western North America ◽  
Willamette Valley ◽  
The North ◽  
Factors Influencing ◽  
Plant Life ◽  
Pear Psylla ◽  
Plant Life Cycle

AbstractFenvalerate resistance was monitored in Psylla pyricola Foerster populations at 51 sites in Washington, Oregon, California, and British Columbia during early 1988. Resistance levels ranged from susceptible in an organic orchard in the Willamette Valley, OR, and at several other sites in Oregon and California, to highly resistant (> 100-fold compared with a susceptible strain) at several sites in central Washington. Generally, resistance levels were greater in the north than the south. In the Wenatchee and Yakima/Ellensburg, WA, areas, pyrethroid resistance was areawide, showing similar levels in both heavily treated and untreated orchards. In the Willamette Valley, OR, pyrethroid resistance was local and more consistent with the treatment histories of individual orchards. Factors influencing regional resistance appeared to be the species pool size of resistant and susceptible pear psylla, the intensity of spraying, and the unique host plant, life cycle, and dispersal attributes of this pest. Reasons for high regional resistance in central Washington and not in southerly areas are unknown, but this pattern is consistent with earlier patterns of insecticide resistance in pear psylla. The observed trends in fenvalerate resistance are discussed in relation to limiting resistance in pear psylla.

Sign in / Sign up

Export Citation Format

Share Document