Effect of amino acids on feeding behaviour of the European corn borer, Pyrausta nubilalis (Hübn.)

Abstract

When incorporated in an agar-based purified diet, a number of amino acids had significant effects on the feeding behaviour of first instar larvae of the European corn borer, Pyrausta nubilalis (Hübn.). The duration of larval feeding periods was used as the criterion of the effects of the amino acids on feeding and was measured indirectly in terms of the population equilibria attained between pairs of experimental diets. Average feeding duration was increased by a number of amino acids, but most notably by l-alanine, dl-α-amino- n-butyric acid, l-serine, and l-threonine. A negative effect on feeding was observed with l-tryptophane, l-arginine, and β-alanine. The borers responded weakly to d-alanine and not at all to d-serine and d-threonine. Although the borers' response to amino acids was superficially similar to the response to sugars, different and independent sensory mechanisms were apparently involved. The effect of l-amino acids on borer feeding was found to be correlated with molecular weight and water solubility, although this property could not account for all the results obtained.