| Popis: |
Fifth-instar larvae of Erinnyis ello feeding on Euphorbia pulcherrima leaves display the following rates and efficiencies: relative growth rate, 0.3 mg/day per mg; relative consumption rate, 2.6 mg/day per mg; approximate digestibility, 45%; efficiency of conversion of digested food, 25%. Chemical determinations performed on the leaves ingested and on the faeces expelled led to the determination of the approximate digestibilities (%) of the major constituents of leaves, as follows: soluble protein, 49; insoluble protein, 87; total lipids, 63; sucrose, 100; pectin, 0; hemicellulose, 52; starch, 88, cellulose, 0. Values (μg) for the daily absorption of minerals by a 3-g (fresh wt) E. ello larva were: K, 11,000; Ca, 5000; Mg, 2100; Cu, 3.3; Zn, 33; Fe, 110, The data suggest that the physiological role of the E. ello midgut β-fructosidase is to hydrolyze the major leaf carbohydrate sucrose, which is not efficiently digested by E. ello midgut α-glucosidase, whereas the physiological role of E. ello midgut β-glucosidase is to accomplish the final digestion of the hemicellulosic β- d -glycans. |
