Effect of Bombyx mori Chitinase against Japanese Pine Sawyer (Monochamus alternatus) Adults as a Biopesticide
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<I>Bombyx mori</I> chitinase (<I>Bm</I>-CHI), with a molecular mass of 75 kDa, was investigated on the possibility that it can serve as a biocontrol agent against the adult Japanese pine sawyer (JPS), <I>Monochamus alternatus</I> (Coleoptera: Cerambycidae). Oral ingestion of purified chitinase at concentrations of 3 μ<small>M</small> (11.25 μg/50 μl) and 0.3 μ<small>M</small> (1.125 μg/50 μl) caused high mortality in JPS, a significant decrease in bark consumption, and, only in high concentration, a slight reduction of body weight. Fluorescence assays indicated that peritrophic membrane (PM) chitin is degraded by the action of orally ingested <I>Bm</I>-CHI at 3 μ<small>M</small> concentration only. Scanning electron micrographs clearly indicated that the beetles that ingested <I>Bm</I>-CHI of the same high concentration had their PM perforated and disrupted, but ultrastructural studies showed that the ingested chitinase did not affect the midgut epithelium. These findings open up the possibility of using insect chitinase as a biopesticidal enzyme. It should have agronomic potential for insect control.
- Agricultural and Biological Chemistry
Agricultural and Biological Chemistry 70(1), 219-229, 2006-01-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry