Sodininkystė ir daržininkystė - Sodininkystės ir daržininkystės institutas

12. W i eseborn W.D. and M orse J.G. Feeding rate of Scirtothrips citri(Moulton) (Thysanoptera: Thripidae) as influenced by life stage and temperature //Environmental Entomologist. 1985. N 15. P. 1515-1518.SODININKYSTË IR DARÞININKYSTË. SCIENTIFIC ARTICLES.2006. 25(1). 152-160.INVESTIGATIONS OF INSECTICIDE EFFICIENCY ON THRIPSTABACI IN LEEKL. DuchovskienëSummaryInvestigations were carried out in garden crop rotation of the experimental field atthe Lithuanian Institute of Horticulture in 2003-2005. Leek cultivars American flagand Campus were sprayed with these insecticides: fastac – 0.2 l/ha, karate – 0.2 l/ha andactara – 0.4 kg/ha. When thrips tabaci were sprayed with insecticides in 2003, biologicalefficiency of insecticides in the crop of both leek cultivars after 4 and 14 days was 100%.After 21 day only actara acted on the crop of leek cultivar American flag effectively(82.1%). The efficiency of fastac, karate and actara in the crop of leek cultivar Campusafter three weeks was correspondingly 84.8, 95.6 and 97.2%. The efficiency of insecticidesin the leek crop of both cultivars after spray on 5 th and 13 th day in 2004 was 100%. After21 day biological efficiency of karate in the crop of leek cultivar American flag was68.7%, actara – 51.7%, and fastac did not acted any more. In the crop of leek cultivarCampus all the investigated insecticides weren’t effective. In 2005 after the first andsecond spray biological efficiency of insecticides in the leek crop of both cultivars wasthe biggest after five days. After that biological efficiency of insecticides started todecrease, and after 13 and 19 days insecticides were almost ineffective. Meteorologicalconditions significantly influenced the abundance of pests and the duration of insecticideeffect during all the years of investigation. Fastact took effect most shortly; karate andactara were efficacious for longer period. Phytotoxical effect of insecticides on plantswasn’t observed. The yield of leek cultivar American flag was significantly bigger in2003, when all the investigated insecticides were applied. Significant yield differencesbetween the sprayed and not sprayed leeks of cultivar Campus weren’t observed. Yieldaverage of both leek cultivars was significantly bigger than this of not sprayed. In2004 significant yield differences weren’t obtained. In 2005 the yield of leek cultivarAmerican flag was significantly bigger after spray with all the insecticides, and thesignificant additional yield of leek cultivar Campus was obtained only after the spraywith actara.Key words: biological efficiency, insecticides, leeks, thrips tabaci.160