Monitoring the appearance and possibility for prevention of the apple sawfly in Croatia
The apple sawfly Hoplocampa testudinea Klug has recently become a widespread pest in Croatian apple orchards. It causes severe damage in the blooming period due to the fact that infested fruit fall off.This article shows results collected over three years of field research on trap catches of sawflies, the period of laying eggs, the appearance of larvae and detection of damage. In the climate of northwestern Croatia, adult sawfly appear in April during the blooming period of the early apple variety of Idared.By monitoring temperatures from January 1, adults were detected when the thermal constant reached 210 day-degrees. Our observations showed that the larvae emerged when the sum of thermal constants reached ca. 110 day-degrees.The investigation of effective control strategies with insecticides showed high efficacy of thiametoxam (Actara), imidacloprid (Confidor), thiacloprid (Calypso) and betacyfluthrin + oxydemeton-methyl (Enduro) and lower efficacy of phosalone (Zolone), chlorpyrifos-methyl (Reldan), and lambda cyhalothrin (Karate).
Effect of Achillea millefolium Strips and Essential Oil on the European Apple Sawfly, Hoplocampa testudinea (Hymenoptera: Tenthredinidea)
The European apple sawfly Hoplocampa testudinea (Klug) (Hymenoptera: Tenthredinidae) is a pest in numerous apple orchards in eastern North America. In Quebec, Canada, the European apple sawfly can damage up to 14% of apples and growers use phosphate insecticide during the petal fall stage to control the pest. Since the insecticide is toxic for beneficial insects, we established flower strips of Achillea millefolium L. (Asterales: Asteraceae) to interfere with the oviposition of the insect as an alternative. Populations of European apple sawfly adults were significantly reduced in areas close to flower strips compared to unmanaged areas (natural groundcover). In order to understand the mechanism of the flower strip effect, we tested the repellent effect of A. millefolium essential oil on populations of H. testudinea. Twenty flowers per apple tree were sprayed during full bloom, the oviposition period of the pest. Sprayed and control flowers were then collected and dissected to note the presence of oviposition scars and eggs of the European apple sawfly. Significantly less scars and eggs were observed on sprayed flowers than on control flowers, which means that A. millefolium had a repellent effect on the insect.
Enumeration of total coliforms, fecal coliforms, and Escherichia coli in foods by hydrophobic grid membrane filter: supplementary report.
Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.