The vine mealybug, Planococcus ficus (Signoret) (Homoptera: Pseudoccocidae), was identified as a new pest of California vineyards first in the Coachella Valley in 1992, and later in the San Joaquin Valley in 1998. We used both non-destructive and destructive sampling techniques to investigate vine mealybug seasonal age-structure, density, within-vine distribution, and parasitism levels. Results from sampled vineyards in the Coachella Valley show mealybug density increased in spring (April - May) and reached peak densities near harvest-time (June). Population densities decreased thereafter. Mealybug distribution on the vine changed throughout the season. From winter and into early spring (March to April), mealybugs were concentrated in the lower vine sections (e.g. on the trunk at ground level). As the season progressed, mealybugs from the second and third generations moved up the vine structure until harvest; afterwards, the mealybug population moved down the vine and was again concentrated in the lower, more protected canopy and trunk sections. Parasitism rates were low with parasitoids not appearing until April; peak parasitism activity (<20%) was in June (primarily Anagyrus pseudococci and Leptomastidea abnormis). The realtively low parasitism levels are attributed to tending ants and the mealybug distribution in protected regions of the vine (underneath the bark) where they were more protected by tending ants and less accessible to parasitoids. Corresponding studies in the San Joaquin Valley (SJV) showed a similar seasonal density and migration, however, the mealybug increase and movement up the vine occurred later in the season. Also, in the SJV, many mealybugs were present on exposed vine sections (e.g., leaves) throughout the summer and fall. This greater exposure was, in part, responsible for higher peak parasitism rates (>80%). Parasitoids were first observed in July and active late in fall (October) beyond harvest time.
Species 1: Homoptera Pseudococcidae Planococcus ficus (vine mealybug)
Species 2: Hymenoptera Encyrtidae Anagyrus pseudococci
Keywords: mealybug age-structure, mealybug distribution
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA