No abstract

In laboratory studies with the codling moth, Cydia pomonella (L.), TH 6043 and TH 6044, new benzoylphenylurea chitin-synthesis inhibitors, were more effective than TH 6045 and diflubenzuron in reducing hatch of eggs from treated adults. With TH 6043 and TH 6044, egg hatch was reduced only when the female of each mating pair was treated. Topical application of diflubenzuron to adults moderately reduced egg hatch while TH 6045 had no effect. Diflubenzuron also reduced oviposition by females. None of these compounds adversely affected mortality, longevity, or mating propensity of adults.

No abstract

Can. Ent. 1 16: 197-202 (1984) An insecticide, diflubenzuron, suppressed 3rd-and 4th-instar larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say), with reduced effect on the tachinid parasite, Doryphorophaga doryphorae (Riley), developing within the larvae. Concentrations applied to potato foliage were 50, 100, 300, and 500 mglL. In laboratory and greenhouse tests, parasite survival was not adversely affected when the 3rd instars were treated with 50 mg/L diflubenzuron but survival decreased to 0 and 4% at 300 and 500 mg/L. Survival and emergence of the parasite from treated 4th instars were not adversely affected at any concentration tested. Fourth-instar beetle larvae were much more tolerant of diflubenzuron than were the 3rd instars. Neither fertility nor the ability to parasitize beetle larvae was adversely affected in adult parasites emerging from treated 3rd or 4th instars. Adult beetles developing from treated larvae mated normally and laid fertile eggs. Foliage consumption by the beetle larvae decreased progressively as dosage of diflubenzuron increased but only slowly once the dosage increased beyond 100 mg1L.

Can. Ent. 116: 1041Ent. 116: -1049Ent. 116: (1984 A sequential egg-mass sample system for Douglas-fir tussock moth; Orgyia pseudotsugata McDunnough (Lepidoptera: Lymantriidae), was designed, based on visual scanning of the lower branches of Douglas-fir trees, Pseudotsuga menziesii (Mirb.) Franco. A branch was removed from each quadrant from the upper, middle and lower crown level, and from the lowest whorl of a total of 59 non-defoliated trees in 10 areas. No consistent trend in egg-mass density per branch could be found between crown levels and no level proved superior as a representative of the tree. Therefore, the lower whorl of branches was selected for survey purposes because of sampling efficiency. Sample stop lines were determined from egg-mass density and variability data collected on 55 sites and subsequent defoliation estimates were related to these densities. The system is designed as an early detection tool to be used only in non-defoliated stands at the incipient stage of an impending outbreak. RburndUn plan d'Cchantillonnage sequentiel des masses d'oeufs de la chenille B houppes du ~o u~l a s (Orgyia pseud~tsugata McD.) a Ct C mis sur pied a partir de ~' o b s e~a t i o n visuelle des branches inferieures de Douglas taxifoliCs (Pseudotsuna menziesii (Mirb.). + -France). Dans chaque cadran, une branche a Ct C prClevCe dans le bas, le milieu et le haut de la cime et sur la plus basse verticelle de 59 arbres, dans 10 kgions. Comme aucune tendance nette de la densit6 des oeufs par branche n'a pu Ctre trouvte entre les diffkrents niveaux de la cime dans les peuplements infest&, on a choisi, pour plus de commoditC, les trois branches les plus basses comme unit6 dlCchantillonnage. Les donnkes techniques des Cchantillons ont Ct C dCtermin&s i partir des densitks et de la variabilitk observkes dans 55 stations, et les estimations de la dkfoliation subsCquente ont Ct C corrCltes a ces densitCs. Le plan est destink B la dCtection prCcoce du dCbut d'une infestation imrninente, uniquement dans les peuplements non dtfolits.