Vine mealybug

Two pheromonal components were detected in airborne collections from the vine mealybug, Planococcus ficus Signoret (Hemiptera Pseudococci dae) in Israel. They were identified as (5 )-lavandulyl senecioate (1) and (5)-lavandulyl isovalerate (II). Compound I has been identified as the sex pheromone of P. ficus in California. The report shows that feral P. ficus mealybugs produce and respond only to (I) whereas mealybugs reared in the laboratory on potato sprouts produce and respond to both (I) and (II). 

Abstract— The sex pheromone of the vine mealybug Planococcus ficus has been identified as a single component, (5)-lavandulyl senecioate 2a. Males were equally attracted to either (S)-2a or racemic 2a, indicating that the unnatural enantiomer does not inhibit male behavioral responses. 

Our overall project goal was to identify and develop pheromones that could be exploited for the management of the four major mealybug pests in California vineyards. We report here the identification, synthesis, and results of field tests of the sex pheromone of the vine mealybug. Within the space of two years, the pheromone-baited traps have become the cornerstone of methods of monitoring this pest in California, and they are also being developed for sale and use in Sonih Africa, the Middle East, and South America. 

Figure L GC chromatogram of volatiles collected from mature female vine mealybug on butternut squash (top) and from uninfested squash (bottom, inverted), Lavandulol 1 and lavandulyl senecioate 2a are indicated.

Because lavandulyl senecioate is chiral, and vine mealybug females produce exclusively die (iS)-enantiomer, the relative attractiveness of pure (5)- and racemic lavandulyl senecioates was tested. Traps baited with either die chiral or racemic pheromone were equally attractive to male mealybugs (racemic, 373 175 [mean SD] (5)-enantiomer, 286 122 two-sample /-test, P = 0.34), clearly demonstrating that die unnatural enantiomer is neidier inhibitory nor synergistic. 

Figure 3. Numbers of male vine mealybugs caught in traps baited with blends of racemic lavandulol and lavandulyl senecioate ranging from 0 100 to 100 100 pg. Note Y-axis is a log scale. Bars surmounted by different letters are significantly different.

Figure 4. Male vine mealybugs caught in traps baited with racemic lavandulyl senecioate, with lures aged for periods of 0 to 3 wk before use. They-axis is a log scale. Controls were lures treated with solvent only. For a given sampling date, there were no differences between treatments, but all treatments were always different from the solvent controls.

Second, male mealybugs and scales are acutely sensitive to their pheromones. For exanple, in the vine mealybug results presented here, pheromone lures loaded with 100 pg of racemic pheromone (i.e., SO pg of the... 

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