Shoaib Freed

Bahauddin Zakariya University, Multan, Punjab, Pakistan

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Publications (6)9.29 Total impact

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    ABSTRACT: Thrips tabaci Lindeman (Thysanoptera: Thripidae) is one of the most important pests of asparagus in China. In this study the effects of five constant temperatures (15, 20, 25, 30 and 35 °C) on the growth, survivorship and reproduction of Proprioseiopsis asetus (Chant) (Acari: Phytoseiidae) fed on T. tabaci was examined under laboratory conditions. Development time of immatures decreased with increasing temperature. The lower egg-to-adult developmental threshold (T 0) and thermal constant (K) of P. asetus were estimated at 15.2 °C and 75.8 degree days by means of a linear model. Fertilized females fed on T. tabaci produced offspring of both sexes, whereas the offspring sex ratio [♀/(♀ + ♂)] of P. asetus at 20-35 °C was female-biased (0.68-0.78) and not significantly influenced by temperature. Survivorship during immature development was significantly influenced by temperature, and was especially low at 15 °C. Pre- and post-oviposition periods of fertilized females shortened with the increase in temperature. The longest oviposition period was 20.4 days, at 25 °C, whereas at 15 °C the mites did not reproduce. Maximum average life time fecundity and mean daily fecundity was recorded at 25 and 35 °C, respectively; the intrinsic rate of increase ranged from 0.05 (20 °C) to 0.17 (35 °C). The results indicate the capability of P. asetus to develop and reproduce at a broad range of temperatures, especially above 25 °C, which can be used for better management of T. tabaci in asparagus.
    Experimental and Applied Acarology 05/2014; · 1.85 Impact Factor
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    ABSTRACT: Peptidoglycan recognition proteins (PGRPs) are non-specific immune molecules of insects, and vertebrates etc., but are not present in plants and nematodes. In the current experiment, a PGRP DNA sequence (2,910 bp containing four exons) was identified from genomic DNA library of Asian corn borer, Ostrinia furnacalis, and a full-length cDNA programming PGRP was cloned (designed as OfPGRP-S) with an open reading frame of 579 bp, having 192 amino acid. This inferred amino acid sequence showed maximum similarity to known lepidopteran PGRPs. Quantitative real-time PCR investigation disclosed the level of mRNA of OfPGRP-S to be constitutively expressed in the whole developmental stages and with higher expression in the mature larvae. Even more the OfPGRP-S was mainly expressed in immune capable organs i.e., fat body and midgut, and was strongly induced by injecting gram-positive bacteria i.e., Staphylococus aureus. Recombinant protein OfPGRP-S could bind to S. aureus and Bacillus thuringiensis which enhance proPO activation in the presence of these microbes. The results indicated that OfPGRP-S is an inducible protein acting as a receptor-type PGRP for enhancing the proPO activation on exposure to bacteria.
    MIRCEN Journal of Applied Microbiology and Biotechnology 08/2013; · 1.08 Impact Factor
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    ABSTRACT: The entomopathogenic fungus Metarhizium anisopliae is currently used as an efficient biological control agent against different insects. The prevalence and genetic variability of the entomopathogenic fungus Metarhizium anisopliae var. anisopliae in Asian countries (China, Laos, Singapore and South Korea) and a European country (The Netherlands) was examined. The fungus was found to be widespread in agricultural and forest soils throughout China especially in the south and south western regions, with a maximum recovery percentage of 81.6, while in Laos it was found to be abundant in the forest soils only, the soil of Netherlands also seemed to be an excellent source of entomopathogens with a significant recovery of insect pathogenic fungi. Simple sequence repeats (SSR) and ITS-rDNA sequence data showed that the isolates are closely linked to each other. The gene diversity (He) and polymorphic information content values of sixty two isolates showed mean values of 0.37 and 0.63. The majority of the isolates belonged to one of the closely related genotypes and these were found to be dominant in the agricultural as well as forest ecosystem. Genetic distances among the isolates according to locations and different sources showed minimal variation ranging from 0.23 to 0.34%, with maximum genetic distance of 0.34% among the isolates from Laos and The Netherlands. The reason for the limited variation is uncertain, however even the similarity index among the isolates can endow with sufficient knowledge for the implications of the methods to develop this fungus as a microbial control agent. Keywords Metarhizium anisopliae –Genetic diversity–Simple sequence repeats–ITS-rDNA–Biocontrol–Phylogenetic analysis
    World Journal of Microbiology and Biotechnology 01/2011; 27(2):359-370. · 1.26 Impact Factor
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    ABSTRACT: Antifeedant activities of the isolated chemical compounds from Ajuga nipponensis, were studied against adult of striped leaf beetles. The methanol, petroleum ether, ethyl acetate and n-butanol extracts at 1.0mg/ml, were used in this study. All four extracts exhibited more than 65 antifeedant index at 24h and ethyl acetate extract showed significant activity against striped leaf beetles with 83.12 antifeedant index. Six compounds and one fraction were isolated by chromatography and their structures were identified by NMR, MS and FTIR spectra. At 2.0mg/ml for 24h the three compounds 20-hydroxyecdysone, acacetin and apigenin showed considerable activities with antifeedant indexes 59.29, 51.22 and 61.55, respectively. In contrast to this the antifeedant indexes of acacetin and apigenin, were sharply reduced as the time extended and that of 20-hydroxyecdysone remained unchanged. In addition, the synergistic effects of two mixtures of secondary metabolites, were studied and no sharp difference was observed.
    Journal of Pest Science 01/2009; 82(2):195-202. · 2.17 Impact Factor
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    ABSTRACT: The bioactivities of destruxins against whitefly, Bemisia tabaci and its natural enemy, ladybird beetle Serangium japonicum were evaluated. Destruxins A and B (DA and DB) showed insignificant ovicidal, oviposition deterrent and systemic insecticidal activities to B. tabaci; however, DA and DB had certain contact virulence to its nymphs. The LC(50) values of DA at 120h to 2nd, 3rd and 4th instars were 89.8 (95% confidence interval as 85.4-94.4), 199.3 (187.7-211.5) and 270.7 (251.5-291.5)mg/L, while the LC(50)s of DB at 120h were 96.5 (92.0-101.2), 216.7 (203.0-231.2), 359.4 (326.6-395.4)mg/L, respectively. In addition, DA exhibited moderate acute contact toxicities towards S. japonicum, the LC(50)s at 48h were 165.4 (132.3-229.4) and 192.5 (148.1-289.2)mg/L for 4th instar larvae and adults. Furthermore, the results from experiments of residual toxicities of DA towards mortalities of 4th instar larvae and adults, pupation rate, emergence rate, average number of egg/female and hatching rate suggested that DA had minimal effects to the ladybird beetle. Generally, the toxicity decreased about 50% from 1st to 3rd-5th day of post-treatment. Specially, the residual toxicity at 50mg/L and the 7th day post-treatment was down to a value not differing significantly from the control.
    Toxicon 11/2008; 53(1):115-21. · 2.92 Impact Factor
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    ABSTRACT: Antifeedant activities of seven chemicals isolated from Ajuga nipponensis were examined in a bioassay against 3 rd instar larvae of Plutella xylostella. Five compounds (luteolin, stigmasterol, acacetin, 20-hydroxyecdysone and fraction 1) showed significant antifeedant activities, with the AFI50 values of 1935.02, 2515.94, 6589.58, 287.58, 2171.31µg/ml after 24h and 1853.20, 3812.24, 2581.43, 103.42, 1429.75µg/ml respectively after 48h of treatment. The synergistic effects of mixtures of secondary compounds were studied and antifeedant index was directly related to the component and the proportion of the mixture i.e., no synergism existed between luteolin and 20- hydroxyecdysone mixture, but the values of CTC for fraction 1, stigmasterol, acacetin, luteolin and 20-hydroxyecdysone mixture were up to 627.07 and 111.72 after 24 and 48h, respectively. In addition, only apigenin showed effectiveness against Diamondback moth, with a high mortality percentage and low consumed leaf area when mixed with avermectins.

Publication Stats

18 Citations
9.29 Total Impact Points


  • 2013–2014
    • Bahauddin Zakariya University
      • Faculty of Agriculture Science and Technology
      Multan, Punjab, Pakistan
  • 2011
    • Jilin Agricultural University
      Shengcheng, Guangdong, China
  • 2009
    • South China Agricultural University
      • Department of Entomology
      Shengcheng, Guangdong, China