Antônio Lopes da Silva

ENSAIO DE CONTROLE À TRAÇA DO TOMATEIRO Scrobipalpuloides absoluta (Meyrick) COM NOVO INIBIDOR DE ECDISE DE ORIGEM VEGETAL

Suwandel is one of the most important traditional rice cultivars in Sri Lanka. The present study was conducted to identify the molecular differences and to determine duplicates among the Suwandel rice accessions conserved at Plant Genetic Resources Centre (PGRC). A total of 20 simple sequence repeat (SSR) markers were used across 11 Suwandel rice accessions. Out of these 20 SSR loci 18 loci showed polymorphism. A total of 47 alleles were detected and the number of alleles per locus ranged from 1-4 with an average of 2 alleles. The frequency of the most common allele at each locus ranged from 45 to 100% with an average of 67%. Genetic diversity among 20 loci ranged from 0.00 to 0.67 with an average of 0.42. Polymorphic information content ranged from 0.00 to 0.62 with an average of 0.35. A phylogenetic tree showed three distinct main clusters with two sub clusters in the cluster three. The highest genetic similarity was obtained between AC 12827 and C 2013-12778 (91%) which can be identified as closely related Suwandel rice accessions. The lowest similarity was recorded between AC 4197 and AC 4366 (27%). According to the similarity matrix and phylogenetic tree, there were no duplicates among the accessions.

CONTROLE QUÍMICO DO Thrips palmi (Karny) EM PEPINO (Cucumis sativum L.)

Menochilus sexmaculatus (Fabricius) predates on soft bodied, plants sap feeding insect pests. This species is a potential biocontrol agent to use in augmentative release programmes and requires more biological and ecological data. The objective of this study was to examine the development biology of M. sexmaculatus and to assess its suitability as a biocontrol agent. The study was conducted in the Entomology Research Laboratory, Department of Agricultural Biology, Faculty of Agriculture, University of Peradeniya from January to June, 2015. All the experiments were conducted under laboratory conditions at 27oC and 80 % RH. Mean incubation period of eggs was 3.0 ± 0.4 days. The total larval duration was 7.1 ± 0.5 days; L1, L2, L3 and L4 durations were 2.1 ± 0.3, 1.1 ± 0.4, 1.9 ± 0.3 and 1.9 ± 0.3 days, respectively. The pre-pupal and pupal periods were 1.1 ± 0.3 and 3.1 ± 0.3 days, respectively. Mean longevity of male and female beetles were 38.0 ± 0.6 and 47.3 ± 1.0 days, respectively. Mean pre-oviposition period was 3.0 ± 0.1 days and the oviposition period was 43.3 ± 1.0 days. The mean body length of L1, L2, L3 and L4 instars were 1.9 ± 0.1, 2.7 ± 0.3, 6.0 ± 0.1 and 7.8 ± 0.5 mm while, the mean width were 0.4± 0.1, 0.9 ± 0.0, 1.2 ± 0.1 and 3.3 ± 0.1 mm. Mean length and width of adult females were 6.2 ± 0.2 and 4.5 ± 0.3 mm respectively, and those of the males were 4.3 ± 0.5 mm and 3.2 ± 0.3 mm, respectively. L1, L2, L3 and L4 larvae consumed aphid nymphs at the rate of 10.3 ± 1.9, 7.5 ± 1.3, 38.1 ± 3.5 and 69.1 ± 3.1per day, respectively. L1, L2, L3 and L4 consumed adult aphids at the rates of 3.3 ± 0.6, 3.3 ± 0.6, 12.1 ± 0.9 and 25.1 ± 1.7per day, respectively. Female beetles consumed 1624.1 ± 0.2 nymphs and 1204.3 ± 1.3 adult aphids during their entire adult life span. Males consumed 1302.0 ± 1.5 nymphs and 1006.4 ± 0.4 adult aphids during their entire life span. The feeding efficacy increased with the larval instars. Feeding Efficacy of M. sexmaculatus adults was higher than larvae.