Attraction of female Mediterranean fruitfly (medfly) to ammonia and to protein baits was studied with an olfactometer. Ammonia bait (1 cc/trap) proved to be an effective lure. The maximum number of females was caught in traps loaded with 0.01 M ammonia solution with a release rate of 5.28/zg/cc/h.A positive correlation was found between female catch and the ammonia release rate of various protein baits, especially from dry protein hydrolysate of which casein hydrolysate was the most effective. However, casein hydrolysate was less attractive than certain ammonia solutions having a lower rate of ammonia release. Elevation of the pH of the liquid commercial baits, Buminal and Naziman, increased the latter's efficacy as medfly baits but the increased stimulation could not be strictly correlated with the increased rate of ammonia release. It is therefore suggested that medfly olfactory response to protein baits is affected not only by ammonia but by other volatiles as well.

No abstract

Attraction of female Mediterranean fruitfly (medfly) to ammonia and to protein baits was studied with an olfactometer. Ammonia bait (1 cc/trap) proved to be an effective lure. The maximum number of females was caught in traps loaded with 0.01 M ammonia solution with a release rate of 5.28 μg/cc/h. A positive correlation was found between female catch and the ammonia release rate of various protein baits, especially from dry protein hydrolysate of which casein hydrolysate was the most effective. However, casein hydrolysate was less attractive than certain ammonia solutions having a lower rate of ammonia release. Elevation of the pH of the liquid commercial baits, Buminal and Naziman, increased the latter's efficacy as medfly baits but the increased stimulation could not be strictly correlated with the increased rate of ammonia release. It is therefore suggested that medfly olfactory response to protein baits is affected not only by ammonia but by other volatiles as well. RÉSUMÉ Le rôle de l'ammoniaque dans l'attraction des femelles de la mouche méditeranéenne aux attractifs è base d'hydrolysars de proteines L'attraction de la femelle de la mouche méditeranéenne è l'ammoniaque et aux attractifs protéiniques a été étudiée au moyen de l'olfactomètre décrit par Gothilf & Galun (1982). L'ammoniaque (1 cc/piege) s'avéra être un attractif efficace. Le nombre maximum de femelles fut attrappé dans les pièges chargés avec une solution d'ammoniaque 0.01 M ayant une vitesse de diffusion de 5.28/μg/cc/h. Une corrélation positive a été trouvée entre les captures de femelles et les vitesses de diffusion de divers attractifs protéiniques, particulierement ceux à base d'hydrolysats de protéines secs parmi lesquels le plus effectif a été l'hydrolysat de caséine. Toutefois, l'hydrolysat de caséine a été moins attractif que certaines solutions d'ammoniaque ayant une vitesse de diffusion plus basse. Une hausse du pH des attractifs liquides commerciaux, Buminal et Naziman, a augmenté leur efficacité en tant qu'attractifs pour la mouche méditeranéenne; toutefois la stimulation plus intense n'a pu étre mise en correlation stricte avec une vitesse accrue de la diffusion de l'ammoniac. C'est pourquoi il est suggéré que la réaction olfactive de la mouche méditerranéenne est régie, non seulement par l'ammoniaque mais aussi par d'autres substances volatiles.

Two closely related plusiinae moths, Autographa gamma Linnaeus and Cornutiplusia circumflexa Linnaeus, are sympatric in Israel. Both species use identical sex pheromone components but in different ratios, and do not attempt to mate with each other. In addition to the effective reproductive separation by their sex pheromones, the sexual behavior of both species was compared to determine whether the lack of selection pressure might create additional barriers to cross-attraction and cross-mating. We found the gamma moth to be sexually active almost equally throughout the scotophase, whereas the sexual activity of C. circumflexa was limited to a short period at the end of the scotophase when most of the gamma moths had already mated. Higher levels of calling were observed with older females. There was a close relationship between pheromone titer and calling activity in both species.

The composition of theAutographa gamma sex pheromone was reexamined and only (Z)-7-dodecenyl acetate and (Z)-7-dodecenol were identified by capillary GC, GC-MS, and dimethyl disulfide derivatization and subsequent GC-MS analysis. The fatty acid content of the pheromone glands was also studied, and a series of saturated and unsaturated acids was identified. However, most of the related pheromonal compounds were not detected. The male response to the pheromone components was studied in a flight tunnel and compared with the response to calling females. The best synthetic baits evoked a response similar to that observed to the virgin females, but males spent significantly more time at calling females than at the synthetic baits. The preferred synthetic baits consisted of (Z)-7-dodecenyl acetate alone or of a blend with 5% (Z)-7-dodecenol. Increasing the relative amount of the alcohol caused a gradual reduction in male response, particularly in the last steps of the courtship sequence. The addition of the minor sex pheromone components of the sympatric Plusiinae species,Trichoplusia ni andChrysodeixis chalcites, to theA. gamma pheromone was also investigated in the flight tunnel. Some of these components exhibited a significantly antagonistic effect on theA. gamma male courtship behavior. The most potent antagonists were (Z)-5-dodecenyl acetate and (Z)-9-tetradecenyl acetate. The response ofA. gamma andT. ni males to conspecific and heterospecific females was also compared in the flight tunnel. WhereasA. gamma males were attracted only to their conspecific females, a small percentage ofT. ni males were also attracted toA. gamma females and 11% performed the whole courtship sequence.

No abstract

No abstract

Capillary gas chromatography indicated the presence of (Z)‐7‐dodecenyl alcohol and (Z)‐7‐dodecenyl acetate in the abdominal tip extracts of female Cornutiplusia circumflexa (L.) (Lepidoptera: Noctuidae: Plusiinae) moths. Gas chromatography combined with mass spectrometry and dimethyl disulfide derivatization confirmed the structure of these two principal pheromone components. In a flight‐tunnel bioassay, a 5:1 blend of alcohol and acetate elicited the complete courtship sequence by males. The response was comparable to that evoked by a live virgin female, but males spent significantly longer time at calling females than at the synthetic source. The 5:1 blend was also attractive to male C. circumflexa in the field, as indicated by catches in traps baited with this mixture. (Z)‐7‐dodecenyl alcohol alone was slightly attractive whereas (Z)‐7‐dodecenyl acetate alone was completely inactive. C. circumflexa is the first reported Plusiinae species which utilizes (Z)‐7‐dodecenyl alcohol as the major pheromone component.