Sitona lineatus flight patterns in the pea growing region of northern Idaho and eastern Washington were monitored with omnidirectional sticky traps from 1974 to 1976. Trapping sites ranged in altitude from 256–1006 m. Flight occurred from April to September in all years of study, but spring migration occurred at approximately the same time at all trapping sites within each year of the study. Late‐summer migration by new generation adults did not occur at nearly the same time for each study site over the 3 years of the study, but appeared to follow the maturity of peas. RÉSUMÉ MIGRATION SAISONNIERE ET VOL DU CHARANÇON DES FEUILLES DU POIS, SITONA LINEATUS, DANS L'IDAHO DU NORD ET WASHINGTON ORIENTAL Les caractéristiques du vol de Sitona lineatus dans la zone de culture du Pois du Nord de Idaho et de l'Est de Washington ont été examinées aves des pièges omnidirectionnels de 1974 à 1976. Les lieux de piégeages se situaient entre 256 et 1006 m. Les migrations printanières dans toutes les localités se sont produites à peu près à la même époque chaque année, indépendamment de la date de semis des pois, de leur phénologie, de la densité de population de Sitona lineatus ou du temps. Les migrations estivales tardives des adultes de la nouvelle génération n'ont pas eu lieu toujours à la même époque chaque année dans toutes les localités mais suivant la maturité des pois. Les pièges s'étageaient entre 61 et 183 cm. Aux périodes de vols les plus importantes, plus d'adultes étaient capturés aux niveaux les plus élevés alors qu'aux autres périodes, les captures étaient à peu près les mêmes à tous les niveaux. Ces résultats conduisent à la conclusion qu'il y a une véritable migration chez Sitona lineatus.

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Field experiments were conducted to determine growth and yield responses of Pisum sativum L. to defoliation by adult Sitona lineatus (L.). Seedlings grown under conventional (moldboard plowed) and conservation (chisel plowed) tillage treatments were infested for a 1‐week period with 0, 1 and 8 weevils per plant at two times: at 75% field emergence and 1 week later. After the early infestation, defoliation for the control, low and high weevil densities was about 0, 15 and 50%, respectively, while defoliation after the late infestation was about 0, 10 and 35%. An undercompensatory growth response was observed in one experiment after seedlings were subjected to moderate levels of early defoliation. Exact compensation was observed in two experiments after early infestations of low and high Sitona densities. Sitona defoliation reduced the number of pods per plant and pod length in two experiments. However, seed biomass was never significantly reduced. Averaged over all experiments, reduction in seed biomass due to high Sitona densities was 10 and 5% for early and late infestations, respectively. Tillage treatments did not affect Pisum compensatory growth response, although yield components were sometimes greater in conservation tillage than in conventional tillage, possibly due to slightly greater soil moisture in the conservation tillage plots.

Granulosa cells from follicles of different sizes from Booroola x Merino ewes which were homozygous (FF), heterozygous (F+) or non-carriers(++) of a fecundity gene were obtained 0-48 h after cloprostenol injection on Day 10 of the oestrous cycle. The highest mean amounts of cAMP produced by the cells did not differ between the genotypes. However, in the ++ ewes it was attained by cells from follicles greater than or equal to 5 mm in diameter, whereas in F+ and FF ewes it was attained by cells from follicles 3-4.5 mm in diameter. Cells from 1-2.5-mm diameter follicles of FF ewes were more sensitive to FSH and LH than were corresponding cells from F+ or ++ ewes. Granulosa cells from greater than or equal to 5 mm diameter follicles of ++ ewes 12-24 h after injection of cloprostenol had a lower mean response to FSH and LH than did cells obtained 0-6 or 36-48 h after cloprostenol. No such effect of time was evident for cells from any size of follicles obtained from F+ or FF ewes. In 1-2.5-mm diameter follicles, the mean aromatase activity of granulosa cells from ++ and F+ ewes was similar, but significantly lower than that of cells from FF ewes. In 3-4.5 mm diameter follicles, the mean aromatase activity of cells from F+ and FF ewes was similar, and significantly higher than that of cells from ++ ewes. For all 3 genotypes, there was a significant positive relationship between FSH or LH stimulation of granulosa cell cAMP production and cellular aromatase activity.

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