Unusual pheromone chemistry in the navel orangeworm: novel sex attractants and a behavioral antagonist.

Using molecular- and sensory physiology-based approaches, three novel natural products, a simple ester, and a behavioral antagonist have been identified from the pheromone gland of the navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae). In addition to the previously identified (Z,Z)-11,13-hexadecadienal, the pheromone blend is composed of (Z,Z,Z,Z,Z)-3,6,9,12,15-tricosapentaene, (Z,Z,Z,Z,Z)-3,6,9,12,15-pentacosapentaene, ethyl palmitate, ethyl-(Z,Z)-11,13-hexadecadienoate, and (Z,Z)-11,13-hexadecadien-1-yl acetate. The C(23) and C(25) pentaenes are not only novel sex pheromones, but also new natural products. In field tests, catches of A. transitella males in traps baited with the full mixture of pheromones were as high as those in traps with virgin females, whereas control and traps baited only with the previously known constituent did not capture any moths at all. The navel orangeworm sex pheromone is also an attractant for the meal moth, Pyralis farinalis L. (Pyralidae), but (Z,Z)-11,13-hexadecadien-1-yl acetate is a behavioral antagonist. The new pheromone blend may be highly effective in mating disruption and monitoring programs.

Partial purification of plasma phenoloxidase of the yellow fever mosquito Aedes aegypti L. (Diptera: Culicidae).

A nitrocellulose-based assay was developed using a dot-blot apparatus to detect phenoloxidase activity in column fractions. Using this assay, plasma phenoloxidase was partially purified from Aedes aegypti larvae using hydrophobic interaction chromatography, gel filtration, and ion-exchange chromatography. The molecular weight (M(r)) native enzyme was 130,000, and it contained subunits of 76,000, 62,000, and 58,000. Two phenoloxidase peaks were observed by ion exchange chromatography, and these fractions had distinct polypeptide profiles as detected by SDS-PAGE.