The Effect Of Palm Tree Leaves On Growth Index And Midgut Digestive Enzyme Activity Of Brontispa Longissima With Different Growth Phases

To study effects of coconut palm leaf to growth index and digestive enzyme activity of Brontispa longissima in different stages, Brontispa longissima's feeding choices to coconut palm leaf in different growth stages are discussed. By adopting leaf disc method,Brontispa longissima's feeding choices to coconut palm leaf in different stages are studied;Coconut palm leaf's effects to growth and development as well as reproduction of Brontispa longissima in different growth stages are studied by applying indoor laboratory feeding. Content difference of various components of coconut palm leaf as well as correlation with growth index of Brontispa longissima in the different growth stages are discussed; At the same time, it studies the coconut palm leaf 's effects to main digestive enzyme activity of mid intestine of Brontispa longissima, and correlation with growth index of Brontispa longissima, the results are as follows:1. There are significant differences for Brontispa longissima 1th and 4th larvae and adult's feeding percentage to coconut palm leaves at different growth stages. Among them,unemerged heart leaf are favored by Brontispa longissima 1th and 4th larvae. 1th larvae has more strong selectivity compared with 4th larvae. 1th larvae is favored to eat coconut unemerged heart leaf,followed by the Self-emerged leaf,full emerged leaf should not be chosen,while except 4th larvae is partial to eat unemerged heart leaf,there is no significant difference to the Self-emerged leaf and the full emerged leaf. After enter into the adult stage, it is geared towards feeding full emerged leaf, there is no significant differences to feeding choice of the unemerged heart leaf and the Self-emerged leaf.2. Use unemerged heart leaf?Self-emerged leaf and full emerged leaf to feed Brontispa longissima, find that when feed full emerged leaf, there are the shortest larvae development duration (24.33 D), the highest survival rate (77.67%), and the biggest egg hatching rate (88.47%). Specifically, full emerged leaf are the most appropriate host growth stage to Brontispa longissima.3. Except the moisture content reduces with the increase of leaf maturity, sucrose,starch, crude fiber, crude protein and fat content increase with the maturity of leaf. At the same time, water content of coconut palm leaf and larval development period are significantly and negatively correlated, namely the higher water content of leaf, the shorter period of developmental duration of the larva. At the same time,content of fiber is significantly and positively related with eclosion rate, namely the higher blade crude fiber content, the higher eclosion rate of Brontispa longissima. But nutrient content of coconut palm leaf has no significant correlation with egg hatchability, spawning, larval survival rate and pupa weight.4. After palm leaf beetle respectively feeds unemerged heart leaf?Self-emerged leaf and full emerged leaf, intestinal digestive enzyme activity has significant differences among them. The invertase, amylase, protease and lipase activities are the highest when feeding unemerged heart leaf, while they are the lowest when feeding Self-emerged leaf and full emerged leaf; Cellulase has no significant differences with hemicellulase. At the same time, in the correlation analysis of intestinal digestive enzyme activity and growth index of coconut leaf beetle, the amylase activity has significant negative correlation with larval development period and has positive correlation with the larval survival rate, namely the higher amylase activity, the shorter development period, the higher larval survival rate.At the same time, activities of lipase has significant negative correlation with larval development period?Others digestive emzymes activity have no significant correlation with growth index of Brontispa longissima.