An investigation into the effects of adjuvants on the ovicidal activity of neem triterpenes

In this thesis we examine the effect of a range of different adjuvants on the ovicidal activity of neem triterpenes to the eggs of the two spotted mite (Tetranychus urticae (C L Koch)). Eight different adjuvants were tested in combination with a neem triterpene extract. Four of the adjuvants contain different compounds (monoterpenes, lecithins and ferrullic acid esters) which are known to interact with cell membranes and may be responsible for the observed penetration enhancement effect. Using a confocal microscope, Neem triterpenes, when applied in the presence of de-bittered neem oil, were observed to cross the egg shell barrier and penetrate the interior of the egg.