| Henosepilachna vigintioctopunctata(Fabricius)is an important economic pest that mainly harms Solanum crops such as potatoes,tomatoes and eggplants.The changes of plant nutrients such as protein and carbohydrates not only affect plant yield and quality,but also affect insect growth,reproduction and outbreak.The determination of the host plant protein and carbohydrate components could preliminary understand the nutritional proportion of the artificial diet of H.vigintioctopunctata,and provide a theoretical basis for the development and formulation of the artificial feed of H.vigintioctopunctata.Proteins and carbohydrates are important nutrients that affect insect outbreaks.The ratios of proteins and carbohydrates can significantly affect the survival,growth and fertility of insect.The proportion and content of protein and carbohydrate in artificial feed determine the growth and survival of the H.vigintioctopunctata larvae.In this paper,H.vigintioctopunctata host plant leaves were used to measure the water,crude fat,protein,carbohydrate and total amino acid content.According to the content of different leaves,the optimal ratio of protein and carbohydrate to H.vigintioctopunctata larvae was obtained.The purpose of research is to provide a theoretical basis for the development,preparation and optimization of the artificial feed of H.vigintioctopunctata,and to further understand the nutrient regulation of the H.vigintioctopunctata larvae and adult.The main results are as follows:1.The dynamic trend of the nutritional structure of four host plant leaves of the H.vigintioctopunctata.The water content of Solanum nigrum L leaves,potato leaves,tomato leaves and eggplant leaves at different ages and months were not consistent,but the water content of potato leaves(848 mg/g)was significantly higher than that of Solanum nigrum leaves(732 mg/g),tomato leaves(782 mg/g)and eggplant leaves(700 mg/g).The trends of crude fat content in the leaves of the four host plants at different ages and months were not consistent.The crude fat content in the leaves of Solanum nigrum L.and tomato leaves were 48 mg/g and 49 mg/g,respectively,which were significantly higher than that in eggplant leaves and potato leaves.The most important nutrient components of plant leaf were protein and carbohydrate.The dynamic trend of protein content in the four host plants leaves are fluctuating,and the protein content of the leaves of Solanum nigrum L.(78mg/g)significantly higher than the protein content of other host plant leaves.The dynamics of carbohydrate content in different host plants at different ages were consistent.There was no significant difference in carbohydrate content between the 5th to 35 th day of the four host plants.There is significant difference between Solanum nigrum L.leaves and tomato leaves in soluble sugar content,but both of them are significantly higher than that potato leaves and eggplant leaves.Free amino acids are important flavor substances and quality indicators of vegetables.The dynamics of free amino acids in four host plants are not consistent.The total amino acid content of potato leaves(1.0mg/g)is significantly higher than that of Solanum nigrum leaves(0.79 mg/g)and tomato.Total amino acid content of leaves(0.78 mg/g).2.Effect of dietary protein and carbohydrates on survival and growth in larvae of the Henosepilachna vigintioctopunctataThe effects of 11 different artificial diets containing protein(p): carbohydrate(c)ratios were determined in larvae of the phytophagus ladybug,Henosepilachna vigintioctopunctata(F.)(Coleoptera: Coccinellidae).We recorded the developmental times and survival rates of the larvae and weighed their pupae.When the concentration of carbohydrates was kept constant while the concentration of proteins was increased(p29:c20,p31:c20,p33:c20,and p35:c20),H.vigintioctopunctata could successfully complete the larval and pupal stages.The highest survival rate and greatest pupal mass of H.vigintioctopunctata were 72% and 19.5 mg,respectively,when reared on thep33:c20 diet.H.vigintioctopunctata larvae,however,were unable to develop into adults when the concentration of protein remained constant while the level of carbohydrates was increased(p20:c23,p20:c25,p20:c27,and p20:c29),or when the total amount(p + c)was kept at 48%(p22:c26,p 24:c24,p26:c22).Evidently,changing the availability of quality diet,especially the total protein levels,can significantly affect the performance to H.vigintioctopunctata.Our results indicated that the maximum development and survival of H.vigintioctopunctata larvae occurred within a narrow range—when the p:c ratio was(33:20).3.A preliminary study of the GF model in H.vigintioctopunctata fourth instar larvaeIn this study,we set 21 different protein and carbohydrate ratios and concentrations,the compromise rules and protein and carbohydrate intake of the 4th instar larva were determined on day 1 and 2-3.The H.vigintioctopunctata fourth-instar larvae were not consistent with the compromise rules for different pc totals and different days.The compromise rule for the first day of the second instar larvae feeding on the 48% artificial worm is the CD rule,and the compromise curve is,and the 2-3 is converted to the ED rule,the straight line is y=-1.17725+0.5851.The fourth-instar larvae fed a total of 59% of the artificial diet of the compromise rule is the ED rule on the first day,the compromise curve is y =-1.251 x + 0.5369,the compromise rule for the second 2-3 days is the ED rule,the curve is y =--2.3800 x + 0.8379.The compromise rule for the first day of the H.vigintioctopunctata feeding on the pc total amount 70% is ED rule,the compromise line is y=-0.6659x+0.6213,and the 2-3 days is the CD rule.When the fourth instar larvae meet the CD compromise rules,the total intake of protein and carbohydrates in the p1:c1 artificial diet is the highest,and as the protein ratio decreases,the protein intake increases and then decreases.When the H.vigintioctopunctata fourth instar larvae were in accordance with the ED rule,there was no significant difference in the total protein and carbohydrate intake with each artificial diet ratio,and the protein or carbohydrate intake increased with the protein ratio.The intake of protein or carbohydrates is gradually decreasing or gradually increasing. |
