| Summary |
Kalata B1 shown to possess potent insecticidal activity. |
| Condition |
Helicoverpa punctigera larvae were raised on artificial diets based on haricot beans. The test diet was supplemented with the kalata B1 peptide (0.825¬¬µmol/g of diet). The control diet contained casein in place of the inhibitor. Twenty neonates were added to each diet, and mortality was recorded every 2¬days. Weight gain was recorded at the sixth day and every second day thereafter. The larvae were reared in 1.5-ml microfuge tubes (one larva/tube) until day eight, when they were transferred to individual plastic containers with lids [Solo (Urbana, IL) plastic portion cups, 28¬ml]. Larvae were fed initially small amounts of diet (40¬mg) that were replaced as required to provide a continuous supply. The larvae were kept in a temperature controlled room at 25¬¬±¬1¬C, 16:8 (light/dark). |
| Result |
Purified kalata B1 was incorporated into an artificial diet and fed to larvae for 16¬days postemergence. Kalata B1 had a significant effect on the development of larvae compared with larvae on a diet free of kalata. No mortality was observed in the first 6¬days, although 50% failed to survive past day sixteen. After 16¬days, none of the 12¬survivors had progressed past the first instar stage of development and weighed 3.3¬mg (¬±1.1 mg standard deviation). Most larvae on the control diet, however, had achieved fifth instar, and the average mass was 284¬mg (¬±96.1 mg standard deviation). |
| AssayType |
Insecticidal |
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