Novel lepidopteran sex pheromone components from Marmara gulosa (Lepidoptera: Gracillariidae)

Improved Synthesis of (Z,E)-9,11,13-Tetradecatrienal, the Sex Pheromone of the Carob Moth Apomyelois (=Ectomyelois) Ceratoniae (Lepidoptera: Pyralidae)

(Z,E)-9,11,13-Tetradecatrienal is a sex pheromone component emitted by virgin females of the Carob Moth Apomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) which is an important pest of Iranian pomegranate fruits. Chemical control of this pest is not possible and biological methods with pheromones are used. The synthesis of the major component of the sex pheromone was achieved in fewer steps and with lower cost than previously. (Z,E)-9,11,13-Tetradecatrienal was synthesised by four steps with 59% overall yield. The coupling of a conjugated dienynol intermediate from E-1,2-dichloroethylene with vinyl magnesium bromide was achieved in good yield and followed by reduction of dienynol with activated zinc in THF-H2O and oxidation gave the aldehyde of the sex pheromone.

Female sex pheromone of the Gelechiid moth Scrobipalpa salinella (Zeller)

The sex pheromone system of Scrobipalpa salinella (Zeller), an important pest of the halophyte Salicornia europaea in the tidal salt marshes, was studied. Z3-12:OAc and Z5-12:OAc were identified from both female pheromone glands and female emissions, but in quite different ratios. Field trapping tests demonstrated that Z3-12:OAc and Z5-12:OAc are essential for optimal attraction of male moths, and a 100:5 blend found in gland extracts is significantly more attractive to males than a 100:50 ratio similar to that found in SPME samples. Small amounts of E3-12:OAc and Z5-14:OAc also were present in pheromone gland extracts. A blend of E3-12:OAc with Z3-12:OAc attracted a few males, but was not as attractive as the binary blend of Z3-12:OAc and Z5-12:OAc. Moreover, addition of E3-12:OAc did not affect captures of males to the primary binary blend. Another glandular component, Z5-14:OAc, had no behavioral activity in field bioassays. Therefore, a synthetic mixture of Z3-12:OAc and Z5-12:OAc in a 100:5 ratio can be used as an effective tool for monitoring and control of this species.

Temperature thresholds and degree-day model for Marmara gulosa (Lepidoptera: Gracillariidae)

The developmental thresholds for Marmara gulosa Guillén & Davis (Lepidoptera: Gracillariidae) were investigated in the laboratory by using 17, 21, 25, 29, and 33 degrees C. The lowest mortality occurred in cohorts exposed to 25 and 29 degrees C. Other temperatures caused >10% mortality primarily in egg and first and second instar sap-feeding larvae. Linear regression analysis approximated the lower developmental threshold at 12.2 degrees C. High mortality and slow developmental rate at 33 degrees C indicate the upper developmental threshold is near this temperature. The degree-day (DD) model indicated that a generation requires an accumulation of 322 DD for development from egg to adult emergence. Average daily temperatures in the San Joaquin Valley could produce up to seven generations of M. gulosa per year. Field studies documented two, five, and three overlapping generations of M. gulosa in walnuts (Juglans regia L.; Juglandaceae), pummelos (Citrus maxima (Burm.) Merr.; Rutaceae), and oranges (Citrus sinensis (L.) Osbeck; Rutaceae), for a total of seven observed peelminer generations. Degree-day units between generations averaged 375 DD for larvae infesting walnut twigs; however, availability of green wood probably affected timing of infestations. Degree-day units between larval generations averaged 322 for pummelos and 309 for oranges, confirming the laboratory estimation. First infestation of citrus occurred in June in pummelo fruit and August in orange fruit when fruit neared 60 mm in diameter. Fruit size and degree-day units could be used as management tools to more precisely time insecticide treatments to target the egg stage and prevent rind damage to citrus. Degree-day units also could be used to more precisely time natural enemy releases to target larval instars that are preferred for oviposition.