Characterization of Granulovirus and Nucleopolyhedrovirus Isolated from Spodoptera Litura

Two baculoviruses were isolated and identified from Spodoptera litura; S. litura nucleopolyhedrovirus (SpltNPV) and S. litura granulovirus (SpltGV). The polyhedra of SpltNPV were about 0.9-1.83 µm in diameter containing multiple virions measuring about 100-280 nm wide and 320-410 nm long. The SpltNPV virions contained nucleocapsids (47-60 nm wide and 300-350 nm long) within an envelope, and the size of capsids measured about 58-60 nm wide and 300-330 nm long. The capsules of SpltGV were about 0.2-0.3 µm wide and 0.45-0.55 µm long containing single virion (60-73 nm wide and 245-267 nm long). The SpltGV nucleocapsids measured approximately 54-60 nm wide and 287-410 nm long, and found singly enclosed within an envelope. The SpltGV capsids measured about 36- 58 nm wide and 175-277 nm long. The restriction endonuclease analyses (REN) revealed that these two baculoviruses did not show any identical restriction pattern. The DNA size of the SpltNPV and the SpltGV was estimated to be 132 kb and 124 kb, respectively. The nucleotide sequence analysis of the polyhedrin gene of SpltNPV had 98% sequence identity to the known SpltNPV (accession number: AF037262); while the granulin gene of SpltGV had 81 % sequence identity to the granulin gene of Xestia c-nigrum granulovirus (accession number: U70069). Based on the sequence analysis, the SpltNPV and the SpltGV are placed as a taxon of Group II NPV and Group GV, respecti vely. Both viruses exhibited general symptoms of polyhedrosis and granulosis. The SpltNPV-infected larvae showed pinkish yellow at the dorsal and lateral sides, while the SpltGV-infected larvae exhibited whitish ventral. The SpltNPV caused a reduction in the larval size while the SpltGV-infected larvae increased in size with bloated integument when lower viral dosages were given. Both viruses infected fat bodies, Malphigian tubules, tracheal matrices, hypodermis, muscles and midguts. The SpltNPV replicated in the nucleus and spread the disease to susceptible tissues within 24-h postinoculation (pj). The SpltGV was found replicating in both nucleus and cytoplasm, and the disease spread gradually after 48-h pj. The LDso of both viruses in neonate larvae of S. litura were 9 .04xl02 polyhedra for SpltNPV and 1.26xl04 capsules for SpltGV. The LTso of both viruses were similar when neonate larvae were fed with similar ranges of viral dosages. The SpltNPV showed a higher virulence in S. litura larvae than the SpltGV. The characterization of these baculoviruses is of particular interest in view of its possible use in biological or integrated control

Mirror of Atiyah flop in symplectic geometry and stability conditions

We study the mirror operation of the Atiyah flop in symplectic geometry. We formulate the operation for a symplectic manifold with a Lagrangian fibration. Furthermore we construct geometric stability conditions on the derived Fukaya category of the deformed conifold and study the action of the mirror Atiyah flop on these stability conditions.Comment: v2: 45 pages, 18 figures; revised expositio

Checklist of spiders in Sungai Dusun Wildlife Reserve, Selangor, Malaysia

Sungai Dusun Wildlife Reserve, Selangor was established since 1964. It comprises an area of 4,330 hectares. It is considered one of the important biodiversity hotspots and also the first reserved area to protect Sumatran Rhinos. A study of the biodiversity of spider was carried out during the Biodiversity Inventory Program at Sungai Dusun Wildlife Reserve, Selangor from 26th to 31st October 2009. Samples were collected at selected area. Throughout the program a total of 89 spiders were collected. Among them, spiders from the family Agelenidae, Araneidae, Lycosidae, Oxyopidae, Pisauridae, Salticidae, Sparassidae and Tetragnathidae were recorded. Members of Lycosidae and Araneidae were easily spotted in this area

Genetic diversity and morphological variations of goosegrass [Eleusine indica (L.) Gaertn] ecotypes in Malaysia

Goosegrass [Eleusine indica (L.) Gaertn] has been a nuisance to growers in Malaysia due to its increased resistance to commercial herbicides, rapid growth and dissemination, and interference with agricultural practices. In the course of developing an apt integrated management to control goosegrass, more information of this weed is needed. The aim of this study was to look into variations among the goosegrass ecotypes sampled throughout Malaysia from the aspects of genotype and phenotype. Sequence-related amplified polymorphism (SRAP) markers were employed in investigating the genetic diversity and relationships among the 18 goosegrass ecotypes. Consequently, 5 primer combinations amplified 13 fragments with the polymorphism rate of 69.23%. At 74% similarity, the ecotypes were clustered into 6 groups. Phenotypic variability of the goosegrass ecotypes was assessed by observing their morphology, growth and seed traits. Goosegrass ecotypes were sorted into 3 major groups at the genetic distance (DIST) of 0.37. Concurrences of the evaluated genetic distance, ecotypes with the closest and most distant relationships were assembled together in Group I which showed high variation even among ecotypes in the same group. Results obtained thus implied high molecular and morphological variations of the goosegrass ecotypes in Malaysia

UPM anjur projek komuniti konservasi tenggiling bersama Orang Asli

TAPAH, 1 Nov – Universiti Putra Malaysia (UPM) menganjurkan projek komuniti “Community-based Conservation of Pangolin for Termites Control in Batang Padang Semai Tribe” di Sekolah Kebangsaan Batu 14, Tapah, Perak, hari ini

Checklist of spiders in Tasek Bera Ramsar Site, Pahang, Malaysia

Established since 1995, Tasek Bera is a wetland of international importance. It comprises an area of 31,120 hectares. It is the largest natural freshwater lake in Malaysia. The natural freshwater lake is rich in local flora and fauna. A study of the biodiversity of spider was carried out during the Biodiversity Inventory Program at Tasek Bera Ramsar Site, Pahang from 20th to 26th May 2009. Throughout the program a total of 216 spiders were collected. Among them, 13 families of spider, namely the Agelenidae, Araneidae, Lycosidae, Nephilidae, Oxyopidae, Pholcidae, Pisauridae, Psechridae, Salticidae, Sparassidae, Tetragnathidae, Theridiidae, and Thomisidae were recorded. Most spiders found on web built between branches are the members of Araneidae, Nephilidae, Psechridae, Tetragnathidae, and Theridiidae while others were either foraging on trees (Oxyopidae, Pholcidae, Pisauridae, and Salticidae) or on the ground (Agelenidae, Lycosidae, and Sparassidae). A high variety of spider species were recorded

Isaria fumosorosea and Metarhizium anisopliae for controlling Atteva sciodoxa (Lepidoptera: Yponomeutidae), a pest of Eurycoma longifolia

Tiger moth, Atteva sciodoxa (Lepidoptera: Yponomeutidae), is a major pest of tongkat ali, Eurycoma longifolia (Simaroubaceae). To find a safe and effective method for controlling the pest, two indigenous entomopathogenic fungi, Isaria fumosorosea and Metarhizium anisopliae, isolated from bagworms Pteroma pendula (Lepidoptera: Psychidae), were bioassayed against the pest. The larvae were separately sprayed with concentrations of 1 × 102 to 1 × 105 conidia mL-1 of each fungal isolate. Both fungi were pathogenic to third instar larvae of A. sciodoxa. However, M. anisopliae was more virulent than I. fumosorosea. The median effective concentrations for M. anisopliae and I. fumosorosea were 4.23 × 10 3 and 8.24 × 104 conidia mL-1 respectively. The median infective times ranged from 4.3 to 10.3 days for M. anisopliae and 7.6 to 16.3 days for I. fumosorosea. Metarhizium anisopliae killed 48 to 88% larvae while I. fumosorosea, 26 to 62% larvae for the lowest and highest concentrations respectively, 10 days after treatment. Spraying of M. anisopliae at 2 × 107 conidial mL-1 suspension reduced the population of A. sciodoxa attacking 2-year-old saplings up to 89%, 7 days after treatment. This study indicates the potential of M. anisopliae for controlling A. sciodoxa

Prey preference of four species of forest spiders to Spodoptera litura and Plutella xylostella

The prey preference of Heteropoda garciai, Olios mahabangkawitus, Ctenus floweri, and Pardosa apostoli was examined on Spodoptera litura and Plutella xylostella in laboratory. These spiders showed a clear preference for P. xylostella compared to S. litura. However, there was no significant difference observed between the second and third instars larvae of P. xylostella. Similarly, the size of prey was not an important factor in the prey selection by H. garciai, O. mahabangkawitus in this study. P. apostoli showed higher preference on smaller sized S. litura larvae

Life table and demographic parameters of rice leaffolder, Cnaphalocrocis medinalis guenee (Lepidoptera: Pyralidae)

Rice leaffolder, Cnaphalocrocis medinalis is important pest species and become a major threat to rice production in many Asian countries including Malaysia. A range of 30 to 80% of rice yield losses was assessed from severely damage fields under epidemic situation in India. Cnaphalocrocis medinalis has history of outbreak in Sekinchan, Selangor in early 1980’s. Understanding the biology and factors that could be manipulated for its control are very limited. Life table and demographic parameters play important role in determining the key factors that responsible for the highest mortality within population. Therefore, the objective of our study was to construct life table and demographic parameters of C. medinalis. A survivorship and fecundity study of C. medinalis was conducted in laboratory (27.2±0.48 °C, 78.4±1.64% RH and 12:12h photoperiod) using three cohorts consisted of 102, 103 and 105 one-day old eggs. The survival and mortality of every life stage were observed and recorded daily. Nine pairs of one-day old C. medinalis adults were used in fecundity study. The laid eggs were observed daily and longevity of adults were recorded. Standard life table parameters and population age structures were calculated from daily records of survival, mortality and fecundity of each cohort. Two-sample t-test was performed in comparing of longevity between adult male and female. The highest mortality was recorded in first instar larvae (22.58%) with K-value of 0.125 indicated that this stage is the key factor in regulating C. medinalis population. A total of 32.26% individuals has successfully reached at adult stage with average sex ratio was 0.96:1.00 (Female: Male). The emergence of first female was on day 28 whilst the last female died on day 43. The earliest egg was laid on day 30 and continued until day 35 with maximum oviposition was on day 31 and 32 which constitute 57.04% of total eggs. The female lived for about 7.56±0.38 days with fecundity of 104.33±5.43 eggs. The intrinsic rate of natural increase (rm) was 0.08 per female per day with mean generation time (Tc) of 31.56 days and doubling time (DT) of 8.19days. This shows that C. medinalis population has increased and build up rapidly in short time period. Our results suggested that the control program should be done during early stage of larvae in order to suppress the C. medinalis population effectively. Life table study of C. medinalis on other local rice varieties should be conducted in determining its survivorship and reproduction on other host varieties