Apple volatiles from whole Red Delicious and Red Astrachan apples were found to be attractive to sexually mature apple maggot flies,Rhagoletis pomonella (Walsh), in wind tunnel bioassays. Extracted volatiles elicited directed upwind movement towards the source and significantly increased the number of male and female flies arriving at the source. A behaviorally active fraction was obtained from crude extract by gas-liquid chromatography and assayed in two types of wind tunnels and by electroantennography. The major components in this fraction, identified by chemical derivatization reactions and GLC-mass spectrometry, were hexyl acetate, (E)-2-hexen-1-yl acetate, butyl 2-methylbutanoate, propyl hexanoate, hexyl propanoate, butyl hexanoate, and hexyl butanoate in a 35∶2 8∶12∶5∶28∶10 ratio. Synthetics of the identified compounds and the natural extract elicited similar behavioral and EAG responses. None of the synthetics or natural components elicited full activity when presented alone.

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We confirm the existence of oviposition‐deterring, fruit‐marking pheromones in Rhagoletis pomonella and R. fausta and demonstrate their existence in five additional species: R. cingulata, R. indifferens, R. mendax, R. cornivora and R. tabellaria. Individuals from (1) different species belonging to different species groups did not recognize each other's marking pheromones, (2) different species within the same species group varied in reaction from complete to no cross‐recognition, (3) different wild populations of the same species always recognized each other's marking pheromones, and (4) a laboratory population of R. pomonella cultured on apples for ca. fifteen generations deposited a marking pheromone less deterrent to oviposition than that from a wild population. Finally, the water‐soluble marking pheromones of R. indifferens and R. cornivora proved effective deterrents to oviposition when collected and reapplied in aqueous solution to uninfested fruit in laboratory cages. ZUSAMMENFASSUNG MARKIERUNGSPHEROMONE BEI RHAGOLETIS—ARTEN, DIE VOR WIEDERHOLTER EIABLAGE ABSCHRECKEN Bei fünf Rhagoletisanen wird der Nachweis von Eiablage‐abschreckenden, Frucht‐markierenden Pheromonen zum ersten Mal geführt: R. cingulata, R. indifferens, R. mendax. R. cornivora und R. tabellaria. Damit erhöht sich die Zahl von Rhagoletisarten auf neun und die Zahl von pflanzenparasitischen Insektenarten auf zehn, bei denen derartige Pheromone bekannt sind. Wenn Glieder dieser fünf Arten und zusätzlich von R. pomonella und R. fausta untersucht wurden auf den Grad des Interpopulations‐ und innerartlichen Erkennens der Markierungspheromone, so ergab sich: 1. Verschiedene Populationen der selben Art erkennen untereinander die Pheromone, unabhängig von Wirt und Herkunft; 2. Verschiedene Arten innerhalb der gleichen Artengruppe variieren in ihrer Reaktion zwischen vollständigem, teilweisem und fehlendem kr***euzweisen Pheromon‐Erkennen; und 3. Verschiedene Arten von verschiedenen Artengruppen erkennen nicht gegenseitig ihre Pheromone, auch wenn sie von Wirten gleicher Gattung oder Art kommen. — Die bisher nicht identifizierten, wasserl***öslichen Markierungspheromone von R. indifferens und R. cornivora erwiesen sich als stark Eiablage‐abschreckend, wenn sie von markierten Früchten gewonnen und in wässriger Lösung bei unbefallenen Früchten in Laborkäfigen wieder angewendet wurden.

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Cross-resistance of the obliquebanded leafroller, Choristoneura rosaceana (Harris), to tebufenozide was reported from laboratory studies before it had been used in commercial orchards in New York State. Bioassays with obliquebanded leafroller larvae from tebufenozide and organophosphate susceptible and resistant colonies were conducted with chlorfenapyr, emamectin benzoate, fenoxycarb, fipronil, spinosad, and tebufenozide to determine if cross-resistance was present before these new insecticides were introduced into commercial orchards. Resistance ratios ranged from 1.1 to 3.2 for all insecticides except tebufenozide (12.8). Significant differences between susceptible and resistant colonies were found with emamectin benzoate, fenoxycarb, and fipronil. The effect of the metabolic synergists piperonyl butoxide (PBO) and diethyl maleate (DEM) on tebufenozide toxicity was examined to determine mechanisms for obliquebanded leafroller resistance to tebufenozide and potential mechanisms for other new insecticides. At a concentration of 20 ppm, PBO and DEM significantly synergized the toxicity of tebufenozide in resistant and susceptible colonies (three- to fourfold). Obliquebanded leafrollers may be resistant to new insecticides with distinct modes of action even if these compounds have not been previously used in commercial orchards.