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- Author or Editor: James D. Hansen x
Two cold storage treatments were evaluated against eggs, early instars, and late instars of the oriental fruit moth [Cydia molesta (Lepidoptera: Tortricidae)] a quarantine pest for Mexico of stone and pome fruit from the United States. In the first, `Delicious' apples (Malus domestica) were infested with these life stages and treated for 13 weeks in cold storage at 38 °F (3.3 °C) in replicated studies. In the second, the same life stages infesting `Delicious' apples were exposed to air temperatures slightly above freezing, 33.3 ± 0.7 °F (0.7 ± 0.4 °C), up to 7 weeks to simulate near commercial storage conditions. Weekly subsamples of the life stages were examined for survival. At 38 °F, complete mortality was obtained for eggs and early instars by the eighth week, and for late instars by the tenth week. At near freezing temperatures, eggs and early instars died by the fourth week, and late instars eliminated by the sixth week. This study demonstrated that the treatments were effective against the infesting life stages.
Durations of ultrasound treatments were evaluated for efficacy in removing or destroying external pests of apples (Malus sylvestris var domestica). Egg hatch of codling moth (Cydia pomonella; Lepidoptera: Tortricidae), was inversely related to time of ultrasound exposure, although egg mortality was less than 60% after 45 min of treatment. Mortality of twospotted spider mite (Tetranychus urticae; Acari: Tetranychidae), and western flower thrips (Frankliniella occidentalis; Thysanoptera: Thripidae), was directly related to ultrasound durations; adding detergent to the ultrasound bath increased treatment efficacy. Ultrasound did not remove san jose scale (Quadraspidiotus perniciosus; Homoptera: Diaspididae), from the fruit surface. Ultrasound, which can be incorporated in the packing line, shows promise as a postharvest phytosanitation treatment against external pests.
Vapor heat treatments to disinfest tropical cut flowers and foliage were evaluated using a commercial facility. Efficacy was determined for specific durations against representative Hawaiian quarantine pests on their plant hosts. Nymphs and adults of aphids, soft and armored scales, mealybugs, and thrips were killed after 1 hour at 46.6C, and both life stages of aphids and armored scales along with mealybug nymphs after 2 hours at 45.2C. Injury to several varieties of Hawaiian floral commodities (Araceae, Musaceae, Zingiberaceae, Heliconiaceae, Orchidaceae, Marantaceae, Lycopodiaceae, Agavaceae, Proteaceae) during these treatments was determined. Large heliconias, most red ginger, bird-of-paradise flowers and leaves, and most foliage were not damaged; anthuriums, pincushion protea, and orchid flowers and foliage were very sensitive to vapor heat. Treatment modification was needed to reduce plant injury to these commodities without losing efficacy. The number of shelf-life days of the treated plant material was estimated from the visual ratings.
Feeding preference of melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) was evaluated on 21 Dendrobium cultivars and the bamboo orchid Arundina graminifolia (D. Don) Hochr. Pigmented flowers resembling the morphotype phalaenopsis from Phalaenanthe sections were preferred over nonpigmented phalaenopsis, Phalaenanthe × Ceratobium hybrids, and bamboo orchids. This study suggests the separation of susceptible cultivars from preferred cultivars as a pest management strategy for melon thrips control.
The two-component quarantine treatment was shown to be effective against at least 7,000 codling moth (Cydia pomonella) fifth instar larvae infesting `Fuji' apples (Malus × domestica) in each required confirmation test involving two sizes of cartons. After cold storage for 55 days at 36 °F (2.2 °C), infested fruit were placed in vented cartons, either 20-lb [7 × 12 × 12.5 inches (17.8 × 30.5 × 31.8 cm)], or 40-lb [12 × 12.5 × 20.5 inches (30.5 × 31.8 × 52.1 cm)], then fumigated with 0.056 oz/ft3 (56 g·m-3) of methyl bromide for 2 hours at 50 °F (10.0 °C). After each treatment, either no survivors were present or no moribund larvae survived beyond the first week of post evaluation of the larvae.
Phytotoxicity from hydrogen cyanide (HCN) fumigation was measured in several varieties of Hawaiian cut flowers and foliage (Zingiberaceae, Heliconia, Orchidaceae, Marantaceae, Lycopodiaceae, Agavaceae, Proteaceae) as a potential disinfestation treatment. Concentrations tested were 2500, 3700, 4600, and 5500 ppm HCN for 30 min. All foliage and most heliconia were undamaged at fumigation levels of 5500 ppm HCN; most protea and `Midori' anthuriums were uninjured at 4600 pm HCN; red and pink ginger were uninjured at 3700 ppm HCN; and all pincushion protea showed phytotoxicity to HCN. Red ginger was quickly damaged when exposed to sunlight immediately after treatment at 2500 ppm HCN. No injury was observed in simulated shipment tests of red ginger and `Ozaki' anthuriums fumigated at 2500 ppm HCN. Wet, red ginger flowers longer than 6 cm were damaged at 2500 ppm HCN, whereas shorter flowers were uninjured. Wet `Ozaki' anthuriums showed phytotoxicity only at 4600 ppm HCN. Wet, treated lycopodium and bamboo orchid foliage was not injured. The number of marketable days and shelf life of the treated plant material were estimated from the visual ratings.
A quarantine treatment was developed against codling moth (Cydia pomonella L.) (Lepidoptera: Tortricidae) for the sweet cherry (Prunus avium L.) cultivars ('Garnet,' `Brooks,' `Tulare,' `Lapins,' and `Sweetheart') exported to Japan. Specific procedures were required to demonstrate treatment efficacy. Dose-mortality responses were measured for each cultivar at regularly incremented concentrations of methyl bromide for 2 hours at 43 °F (6 °C) compared to the dose-mortality curve of an approved cultivar under the same conditions. Based on the overlap of confidence limits, there were no significant differences between new and approved cultivars in group comparisons. In a confirmation test of efficacy, fumigation with methyl bromide at 0.064 oz/ft3 (64 g·m-3) for 2 hours at 43 °F resulted in complete mortality for all codling moth larvae in the treated cultivars. By convention, fumigation at this or the following concentrations [0.048 oz/ft3 (48 g·m-3) for 2 h at 54 to 63 °F (12 to 17 °C); 0.040 oz/ft3 (40 g·m-3) for 2 h at 63 to 72 °F (17 to 22 °C); 0.032 oz/ft3 (32 g·m-3) for 2 h at 72 °F (22 °C) or above] were considered as an efficacious quarantine treatment against the codling moth in sweet cherries. Except for `Brooks,' fumigation did not significantly influence fruit firmness, soluble solids, or titratable acids. Reduction in fruit and stem quality was more associated with temperature than with methyl bromide concentration. `Tulare,' `Lapins,' and `Sweetheart' could be fumigated with minimal change in fruit quality.
Confirmatory tests were performed on a two-component quarantine treatment against the codling moth (Cydia pomonella L.) (Lepidoptera: Tortricidae) for seven apple [Malus sylvestris (L.) var. domestica (Borkh.) Mansf.] cultivars ('Delicious,' `Golden Delicious,' `Braeburn,' `Fuji,' `Gala,' `Jonagold,' and `Granny Smith') intended for export to Japan and Korea. Treatment consists of a 55-day cold storage at 40 °F (2.2 °C) or below, followed by a 2-hour methyl bromide fumigation (0.056 oz/ft3 or 56 g·m-3) at 50 °F (10 °C). No eggs or larvae survived this treatment. Comparison tests were conducted on all cultivars to demonstrate no difference in insect responses between a previously accepted cultivar and proposed cultivars. Concentration-mortality responses were determined for each of the components and no statistical differences were found in the regression slopes of pest mortality with controlling variable (either cold exposure or fumigation) among all cultivars. Descriptive mathematical models, developed for the effects of cold storage on egg mortality and for methyl bromide fumigation on larvae mortality, were sigmoid curve equations.