EFFECT OF INDOL-3 ACETIC ACID ON THE BIOCHEMICAL PARAMETERS OF Achoria grisella HEMOLYMPH AND Apanteles galleriae LARVA

Abstract

Biochemical structures such as lipid, protein, sugar and glycogen are known to play a pivotal role on the relationship between host and its parasitoid. Any changes in these parameters may have potential to alter the balance of the host-parasitoid relation. Taking this into account, the effects of plant growth regulator, indol-3 acetic acid (IAA) on the biochemical parameters of the host and parasitoid were investigated. Achoria grisella Fabricus (Lepidoptera: Pyralidae) is a serious pest and causes harmful impacts on honeycomb. Endoparasitoid Apanteles galleriae Wilkinson (Hymenoptera: Braconidae) feeds on the hemolymph of the A. grisella larva and finally causes mortality of the host. Different concentrations (2, 5, 10, 50, 100, 200, 500, and 1,000ppm) of IAA were added to the synthetic diet of host larvae. Protein, lipid, sugar, and glycogen contents in hemolymph of host and in total parasitoid larvae were determined by Bradford, vanillin-phosphoric acid, and hot anthrone tests using UV-visible spectrophotometer, respectively. Protein level in host hemolymph increased upon supplement of each doses of IAA except for 10ppm. IAA application enhanced the level of sugar at 100 and 200ppm whereas a decrease was observed in lipid at 5, 10, 200, and 1,000ppm doses in host. All doses were effective on the parasitoid larvae. Nevertheless, the most effective dose was 50ppm, which increased glycogen but decreased lipid amount. Similarly, trearment of 1000ppm IAA increased protein level and 100ppm reduced level of sugar. Our study indicated that application of IAA resulted in different effects on the amount of biochemical structures associated with the hemolymph of pest species and its natural enemy. Therefore, results showed that not only the target but also the non-target organisms exposed to widely-used plant growth regulators may be affected and this, in turn may also change the host-parasitoid interaction.