This is a continuing project with the purpose of supporting all aspects of California red scale (CRS) pest management strategies. CRS remains a primary pest of citrus in the San Joaquin Valley.
The objectives of this study were to determine the host plants used by citrus leafminer (CLM) throughout the year in the Southern California (Escondido area), to determine seasonal phenology; to determine the periods of moth flight activity in Southern California (Escondido area), and to determine the species of parasites attacking CLM on various host plants throughout the year in the Southern California (Escondido area).
Several years ago, we identified what appeared to be the main component of the pheromone of the citrus peelminer (i.e., the only compound that was attractive to male moths as a single component), along with several related compounds that were also produced by virgin female peelminer moths. However, in numerous trials conducted over several years in a variety of crops in the Coachella Valley, Riverside, and the Central Valley, the pheromone has not worked well enough and/or consistently enough to be incorporated into routine IPM programs. We suspect that the problem is due to subtle-ties in the chemistry of the pheromone.
Background: The bean thrips, Caliothrips fasciatus (Per-gande), has been reported on more than sixty genera of plants in the state of California, including more than forty cultivated crops. Although early reports suggested that it could cause yield losses in alfalfa, beans, cantaloupes, cotton, lettuce, pears, and peas, it has not been reported as a pest of economic significance in California since 1940, suggesting that perhaps early reports overemphasized its importance. The region of origin of bean thrips is unknown but has been speculated to be California, Florida, or Brazil.
The mission of this project was to investigate the impact of Admire and Assail on the natural enemies suppressing Cali-fornia red scale (CRS) in the San Joaquin Valley (SJV), including Aphytis melinus. We used both Glassy-winged sharpshooter (GWSS) and Citricola scale treatment rates for our tests. This project interfaced with Grafton-Cardwell’s CRB project: “Long-term effects of chloronicotinyls on citrus IPM”.
Citrus peelminer (CPM) has become an economic problem in both the San Joaquin and Coachella Valleys. In the San Joaquin Valley (SJV), attempts to control it chemically are ineffective as are the parasitoids endemic to SJV. Further-more, molecular characterization by Stouthamer et al. suggests that SJV’s CMP is of Mexican origin (i.e., it was imported into Tulare County in bins of grapefruit from Mexico following the December, 1998, freeze).
This project sought to identify the complex of parasitoids attacking soft scales year-round in southern California with the intent of improving biological control of black scale in southern California and citricola scale in the San Joaquin Valley (SJV).
Citrus thrips populations vary from year to year and require that growers and pest control advisors monitor carefully and apply treatments on an as-needed basis. A number of natural enemies (e.g., Euseius tularensis, spiders, lacewings) assist in reducing citrus thrips numbers, but in some years, citrus thrips levels exceed treatment thresholds and lead to economic fruit scarring unless corrective measures are applied. Broad-spec-trum pesticide treatments appear to exacerbate citrus thrips populations. This research project attempts to optimize cultural, biological, and/or chemical controls, which might be used to manage economic citrus thrips populations.
California is one of the last citrus growing regions worldwide to be invaded by the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), which is one of the most significant economic pests of citrus. It makes sense to take lessons learned by others to advance California’s approach to
managing this pest. Thus developing management tools as quickly as possible to monitor the pest (e.g. finding an attractant), to detect the disease (better and faster detection methods) and to employ natural enemies to slow the psyllid’s movement into commercial citrus. This project will afford an opportunity
for researchers to achieve their objectives and results quickly and efficiently by providing a reliable source of psyllids to develop early-invasion management tools. This project will also develop a rearing program for large scale production when necessary.