| Protaetia brevitarsis (Lewis) is an insect which can be seen everywhere, its larvae were saprophagous, which can be fed by rotten straw, weeds and animal manure,etc. On this feature, the the larvae feeding on the maize straw was studied based on the study of its main biological characteristics and intestinal bacteria, the resource components of the larvae feeding on the maize straw were also measured and evaluated. All these were in order to provide a theoretical basis for the conversion of maize straw by larvae.The main results are as follows:1、Protaetia brevitarsis (Lewis) were holometabolism insect, experiencing egg, larvae, pupae and adult. The male adults were18.75±2.61mm in length,9.72±0.71mm in width; the female adults were120.90±2.72mm in length,11.02±1.03mm in width. The distinction between males and females were:males had longer tentacles gill lamellae than females;the males had3Sharp odontoids on the outer edge of the front tibia but the females only the middle odontoid was Sharp; females were bigger than males generally. Egg was white, round or oval,1.85±0.15mm in length.Larvae had chewing mouthparts, head was brown and body bent to the C-shaped ventral, back bulge and multi-transverse wrinkles, back and ventral were both white. Pupa is golden yellow, oval, slightly raised central side.2、It occoured one genetation per year in Taian and overwintered as mature larvae in maize straw, bagasse and other humus. Occasionally overwintered as adult. The adults emerged from first ten-day period of May to the middle ten-day period of October, and oviposited in last ten-day period of May. At28℃, when the soil moisture was15%, eggs had the highest hatching rate reached83.33±5.77%, hatched after8.13±0.096days. The larvae had three instars, the1st instar stage was14.56±0.65days and head capsule width was1.39±0.24mm;the2nd instar33.61±1.23days, head capsule width was2.30±0.15mm;the3rd has the longest stage which was128.32±2.31days, head capsule width was4.21±0.62mm. The adults had the highest fecundity when the soil moisture was15%, the mean number of eggs per female was83.2±16.99spawning period60-85d.3、Experimentally determined the maize straw rot best solution for25days, the best temperature for larvae feeding is28℃. Each instar larvae were no significant differences in digestibility, conversion and utilization aspects. The3rd instar larvae30d stadium had the strongest ability to eat maize straw, single day food consumption was0.5703±0.0405g, were6.30and2.49-fold of1and2instar larvae, frass production was00.4925±0.0301g, were significantly higher than1st instar and2nd instar larvae, which was the best age of conversion of maize straw in a density of225g·kg-1has a better conversion of maize straw.4、Protaetia brevitarsis (Lewis) is a kind of high-protein insect, the protein and fat of the3th instar larvae were49.90%and15.42%.Furthermore, it contained17essential amino acids and glutamic acid, proline and tyrosine were the highest amino acids. It including8human essential amino acids, and the ratio of essential to nonessential amino acids was65.11%.The essential amino acids comprised39.43%of the total amino acids. Methionine was the first limiting amino acid in larvae protein. Essential amino acid index was88.55, which shown it is a good source of protein.The shape of larvae frass was oval granular, which has the feature of dry, odor-free and small. The frass contained34.1%organic matter,1.42%N,1.31%P2O5and1.33%K2O.5、Seven bacteria strains were isolated from the intestine of the larvae of Protaetia brevitarsis (Lewis) by the traditional methods, a systematic study of its physiological and biochemical properties and16S rDNA technology was used to identify. The results showed that the five bacteria strains were Bacillus firmus、Bacillus circlans、Bacillus laterosporus、 Bacillus macerans and Bacillus megaterium, two bacteria strains were belonged to Veillonella and Leuconostoc. |
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