Bio-Economic Changes Due to Long Time Treatment of Carbendazim on Mulberry Silkworm (Bombyx mori L.

The effect of fungicides on silkworm larvae was analyzed with regard to the fact that these beneficial insects are usually affected by fungicides, Daily feeding on 1 and 2g/liter of carbendazim, a systemic fungicide, did not have significant effects on larval and pupal mortality. However the weight of the treated larvae showed considerable weight decrease up to 37% weight.. All the economic traits of male and female adults treated with fungicide decreased but this decrease is not significant in cocoon shell weight and hatching percentage. The comparison of means using Tukey test at 5% confidence level did not show any effect related to the concentration

In vitro establishment of embryonic primary cultures of silkworm, Bombyx mori (Lep.: Bombycidae)

Since the use of insect cell lines for producing bio-pesticides and recombinant proteins is increasing, the establishment of new cell lines will help to enrich this industry. Therefore, several primary cultures were initiated from embryonic tissues of silkworm, Bombyx mori L. using both enzymatic and mechanical methods. The cultures were incubated in TC-100 medium supplemented with 10 and 20% concentrations of fetal bovine serum (FBS) at 27ºC. Among the methods used, homogenizing the embryonic tissue represented the best culture, which reached the confluence state sooner. Six different morphologies were distinguished in the embryonic primary cultures of silkworm including fibroblast-like cells with three sub-forms of A to C, spindle shaped cells, spherical cells and epithelial-like cells. Also, developing primary cultures from B. mori using enzymatic method is not recommended because of its low efficiency

Biochemical changes in haemolymph of silkworm larvae due to pyriproxyfen residue

An experiment was carried out to evaluate the effect of pyriproxyfen residue on silkworm. The mulberry leaves smeared with 0, 1, 10, 75, 150 and 500 ppm concentrations of pyriproxyfen were fed to silkworm larvae in the 1st day after 4th molting. Some biochemical traits of haemolymph such as glucose, urea, uric acid, cholesterol, total protein, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were measured. The results showed that in 24 h after using toxic leaves, the amount of these biochemical compounds significantly decreased in most treatments. These compounds after 120 h had different fluctuations and increased in some doses. (c) 2006 Elsevier Inc. All rights reserved

Suspension culture titration: A simple method for measuring baculovirus titers

The baculovirus-insect cell expression system is an important technology for the production of recombinant proteins and baculovirus-based biopesticides. Budded virus titration is critical when scaling up baculovirus production processes in suspension cultures, to ensure reproducible infections, especially when a low multiplicity of infection (MOI) is applied. In this study, a simple suspension culture titration (SCT) assay was developed that involves accurate measurements of the initial cell densities (ICDs) and peak cell densities (PCDs) of an infected culture, from which the MOI and hence the virus inoculum infectious titer can be estimated, using the established Power-Nielsen baculovirus infection model. The SCT assay was assessed in parallel with two adherent culture-based assays (MTT and AlamarBlue) for the Heliothine baculovirus HaSNPV, and was shown to be more objective, time-efficient and reproducible. The model predicted a linear correlation between log(PCD/ICD) and log(MOI), hence an alternative model-independent SCT assay was also developed, which relies on a well-replicated standard curve relating suspension culture-derived PCD/ICD ratios with plaque or endpoint assay-derived MOIs. Standard curves with excellent linearity were generated for HaSNPV and the industrially significant rAcMNPV, demonstrating the feasibility of this simple titration approach, especially in terms of its applicability to a wide range of virus infection kinetics