For the second time in two decades, the Yuma County Citrus Pest Control District has been successful in eradicating an infestation of California Red Scale in a commercial citrus grove within its boundaries. The first infestation, found in 1973, was declared eradicated in 1980. The latest infestation was found in 1984 and will be eradicated in record time. Eradication can be declared early next year after the third series of three sprayings each.

Initial studies of Fuller rose beetle (FRB) biology have found some adult emergence in late June and early July. No adults woe found in foliage in May or early June, nor was activity noted in August and early September. FRB were not found in early October, but they began expected major emergence in mid-October. Several FRB collected did not have fused wings, atypical for this species. This finding suggests flight ability in FRB, currently unknown to occur.

Two rates of Avermectin were mound- applied; one treatment of Avermectin B one of Carzol were applied by air to citrus in April for control of citrus thrips. Plots were sampled by beating new terminal growth and counting thrips. Ground applications had fewer thrips than applications made by air. Avermectin B1 treatments had significantly fewer thrips than Carzol at all sample dates.

No description available.

During the last 15 years, the Yuma County Citrus Pest Control District (YCCPCD) has twice eradicated infestations of California Red Scale within the district. A third infestation, found in late 1984 is currently being fought with eradication as the goal.

A variety of insecticides have been tested during the last three years to keep pace with the ever-present demand for effective materials to control mites and thrips on citrus. This need is particularly acute with the recent loss of dicofol (Kelthane), which for years was an industry standard for mite control. Some of the more promising new compounds include Avermectin and NC 21314. Comments are included concerning the registration status of some of the compounds we tested. Cautions are given concerning the development of resistance to compounds which are soon to be available.

The control of citrus thrips is a major concern for citrus growers in the Yuma area. Five materials were evaluated for control of citrus thrips on Lisbon lemons at the Yuma Mesa Agricultural Center during July and August of 1985. Although there was no statistically significant differences between treatments, Mavrik appeared to provide the best control of the materials tested. Dimethoate (Cygon) and formetanate hydrochloride (Carzol) were not tested.

No description available.

Since 1973, Yuma County has had three apparently unrelated infestations of California Red Scale (CRS). The Yuma County citrus Pest Control District (YCCPCD) was successful in eradicating the first two in 1980 and 1984, respectively. We are continuing our spray program on the third, but our detection methods indicate that this infestation has now also been eradicated.

Biological agents have been employed in a series of experiments to evaluate their efftcacy,in control of the citrus nematode and Liohippelates eye gnat in the Yuma mesa area. Steinernema riobravis, an entomopathological nematode, considered climatically adapted to western Arizona temperatures, was selected from commercially available sources. Three field trials and a greenhouse study utilizing the nematodes at population ratés of one and two billion juveniles per acre were each unsuccessful in reducing the nematode or insect pest. Poor viability and survival were attributed to the negative results in each of the investigations. The microbial nematicide, DiTera, which was included in two limited trials, was found to be highly effective in suppression of citrus nematode populations infecting Yuma citrus. These results have prompted Abbott Laboratories, manufactures of the product; to establish two demonstration plots in the Yuma mesa area.