| Bactrocera minax(Enderlein),(Diptera: Tephritidae),widely distributed in China,is one of the most important pests in the citrus industry.Adult flies need a lot of nutrition supplement,and are characterized by show a strong tendency to sugar and protein.The adult bait developed by these characters has been widely applied in the field and achieved good control effect.At present,little knowledge about the feeding selectivity of adults in different ages to sugars and proteins,and the effects of sugar and protein on their physiological content and digestive enzyme activity.In this paper,the feeding selectivity of adults in different ages(1,5,10,15,20,30 days old)was studied,and the feeding characteristics of adults at different stages after emergence were determined.Meanwhile,we also studied the changes of physiological and biochemical substances in adults.This study would provide theoretical basis for the formulation of artificial diet of adults,and provide new ideas for the management of adults.The main results are as follows:1.The feeding characteristics of sugar and protein on different day-old adults.The high selectivities on adults fed with sucrose,sucrose + peptone for sugar were 5 and 15 days old,20 and 10 days old for peptone,and 15 and 1 days old for sucrose and peptone.The maximum intake of sugar and protein is different in adult flies.The maximum intakes of sucrose,peptone,sucrose + peptone were 18.35 mg,14.09 mg and 16.15 mg,respectively.The addition of protein in sucrose could be able to promote the feeding to protein foods in advance,and delay the feeding to sucrose.2.Effects of sugars and proteins on the physiological substances of different dayold adults.The highest soluble sugar contents of adults fed sucrose,peptone,sucrose + peptone,were 96.23 ?g / mg(15 days old),10.76 ?g / mg(1 day old),73.58 ?g / mg(10 days old),respectively.The highest soluble protein contents of adults fed sucrose,peptone,sucrose + peptone,were 20.60 ?g/mg(30 days old),15.90 ?g/mg(1 day old),37.30 ?g/mg(30 days old),respectively.The highest glycerin content 667.75 ?g/mg(10 days old).),146.59 ?g/mg(3 days old),490.21 ?g/mg(10 days old),respectively.The highest dry matter content s of adults fed sucrose,peptone,sucrose + peptone,were 36.90%(20 days old),31.67%(3 days old),37.27%(30 days old)).The soluble sugar,soluble protein,glycerol and dry matter in the adults fed on either sucrose or sucrose + peptone could be accumulated.Some glycerol and dry matter could be only accumulated in the adults fed on peptone.The addition of peptone in sucrose promoted the accumulation of soluble protein and has a certain weakening effect on accumulation of soluble sugar and glycerol.The water content of the adult decreased with age,among which the water content of the adult increased when fed on sugar or peptone.The dry matter content of adults increased with age,and the sucrose and adults fed peptone had the highest dry matter content in the body earlier than the adults fed sucrose + peptone.The maximum dry matter contents in the adults fed sugar or peptone were earlier than that of adults fed sucrose + peptone.3.Effects of sugars and proteins on digestive enzyme activities of flies in different ages.The midgut protein content of different day-old flies: 5,10,15 and 20 days old > 1 day old when fed on sucrose;10,15 and 20 days old > 1 day old when feed on sucrose + peptone.The sucrase activity of different day-old flies: 5,10,20 days old > 15 days old > 1 day old when fed on sucrose;10,15 and 20 days old > 1 day old when feed on sucrose + peptone.The trypsin activity of different day-old flies: 1,15 days old > 5,10,20 days old when feed on sucrose + peptone.The midgut protein content and digestive capacity in midgut increased with the growth and development of flies.The midgut protein content and midgut digestive enzyme activity of flies could be affected by sugar and protein.Flies fed on sucrose + peptone promoted the secretion of trypsin and decreased the secretion of sucrase and fed on sucrose promoted the re-secretion of sucrase. |
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