<p class=\"MsoNormal\" style=\"line-height: normal; margin: 0in 0in 0pt; mso-layout-grid-align: none;\"><strong style=\"mso-bidi-font-weight: normal;\"><span style=\"font-family: \'Times New Roman\',\'serif\'; font-size: 12pt;\">The present effort was undertaken to study the influence of<span style=\"mso-spacerun: yes;\">&nbsp; </span>acetone extractives of bark</span></strong></p>
<p class=\"MsoNormal\" style=\"line-height: normal; margin: 0in 0in 0pt; mso-layout-grid-align: none;\"><strong style=\"mso-bidi-font-weight: normal;\"><span style=\"font-family: \'Times New Roman\',\'serif\'; font-size: 12pt;\"><span style=\"mso-spacerun: yes;\">&nbsp;</span>of <em>Oroxylum indicum </em>on the cocoon characters; silk filament characters and esterase enzyme activity of silk worm <em>Bombyx mori </em>(L.) (Race: PM x CSR2). The soxhletation was followed for the obtaining acetone extractive of bark of Oroxylum indicum (L). Three concentrations (5ppm; 10ppm and 20ppm) of extractive were prepared. The fifth instar larvae were utilized for the experimentation. Soon after the fourth moult, the fifth instar larvae were grouped into five groups (each with hundred individuals) ( Untreated control; Acetone treated control; 5ppm extractive; 10ppm extractive and 20ppm extractive). Ten microliters of each concentration of extractives were topically applied to respective group to the individual larva at 48 hours after the fourth moult. The larvae were maintained through standard schedule. <span style=\"mso-spacerun: yes;\">&nbsp;</span>Ten larvae from each group were utilized for analysis of electrophoretic esterase pattern on fifth day. The silk worms were sacrificed, haemolymph and silk gland samples were isolated and analyzed by using 7.5% of native gel electrophoresis. <span style=\"mso-bidi-font-style: italic;\">Acetone extractives of<em> O.indicum </em></span><span style=\"mso-spacerun: yes;\">&nbsp;</span>at 5 ppm, 10 ppm and 20 ppm concentrations recorded maximum cocoon weight (1.95,1.84,1.76 gm), shell weight (0.40, 0.35, 0.33gm), pupal weight (1.55, 1.49,1.43). All concentrations of the bark extract of <em>O.indicum</em> recorded higher cocoon, shell, and pupal weight than the control</span></strong><strong style=\"mso-bidi-font-weight: normal;\"><span style=\"font-size: 12pt;\"><span style=\"font-family: Calibri;\"> (untreated and acetone treated). </span></span></strong><strong style=\"mso-bidi-font-weight: normal;\"><span style=\"font-family: \'Times New Roman\',\'serif\'; font-size: 12pt;\"><span style=\"mso-spacerun: yes;\">&nbsp;&nbsp;</span>There was a gradual increase in the silk yield with an increase in the concentrations of bark extracts <em>O. indicum </em>from 5 ppm, 10 ppm and 20 ppm concentration of Oroxylum indicum (L). Efficient use of acetone extractives of Oroxylum indicum (L) may open a new avenue in the silk yield.</span></strong></p>