| Green lacewings(Insecta: Neuroptera)are important predators,of which 1350 species,86 genus are known in the world.The resources of green lacewing are abundant in China.109 species,18 genus of green lacewings have been recorded.They are one of the most important predatory natural enemies for pest control in agriculture and forestry fileds because of their wide distribution,large population and extensive range of prey species.Mallada basalis(Walker)has high potential value of being available biological control agent because of their strong reproductive capacity,large predation,effective searching ability and broad prey range.How to efficiently mass rear is one of the key issues of making use of green lacewing in biological control.Traditonal rearing procedures of this predator are often time consuming and expensive.And larval cannibalism of green lacewing is also the key factor which affects the reproduction scale and cost in mass rearing.The main objective of our study was to develop an artificial diet suitable for mass rearing,and to clarify intraspecific competition law of M.basalis larvae by study on the relationship between larval cannibalism and different factors,such as feeding density,hunger time,food types and amount,temperature,humidity and photoperiod.The results were as follow: 1 Several artificial diets were prepared,and the development and reproduction of M.basalis fed on these diets was claritiedFive artificial diets AD1~ AD5 were prepared which included egg,honey,seawater spirulina,trehalose,beer yeast powder,potassium sorbate,Vitamin C,Antheraea ernyi pupae,A.pernyi body contents and sucrose.The results showed that M.basalis females laid no eggs when larvae were fed artificial diets AD2,which sugest AD2 was not suitable for them.It was able to develop and reproduce when fed AD1,AD3,AD4 and AD5.However,the offspring of M.basalis fed AD5 degraded significantly.The rearing effect on AD1 was as well as AD4.But AD1 without seawater spirulina cost less than AD4.So considering feeding effect and cost,AD1 is the best formula among 5 artificial diets.The main biological parameters of M.basalis offspring fed 5 artificial diets was systematically evaluated.F1 3rd instars reared on AD1 required 4.48 d to develop to the pupal stage,which was significantly shorter than 3rd instars on AD2 and AD3 at 6.92 and 5.68 d,respectively.There were significant differences in F1 adult longevity among the 3 diets,and the longevities in AD1(39.40 d)and AD3(30.11 d)treatments were significantly longer than AD2(4.75 d).The F1 female oviposition period was significantly longer in AD1 treatment(22.70 d)than AD3(5.25 d).The daily oviposition and female oviposition from AD1(16.41 eggs/female·day and 476.67 eggs/female)were significantly greater than those from AD3(3.11 eggs/ female·day and 19.75 eggs/female).The egg hatch and pupation rate on AD1(100.0% and 63.3%)were significantly larger than those on AD2 and AD3.F2 hatch rate on AD1(70.4%)was significantly larger than that on AD3(63.0%).The durations of F1 1st larvae,2nd larvae,pupae and F2 egg,2nd larvae reared on AD4 were significantly shorter than those on AD5.The F1 adult longevity and F2 oviposition period in the AD4 treatment were significantly longer than those in the AD5 treatment.The F1 female proportion,daily oviposition,female oviposition,emergence rate,F2 daily oviposition,female oviposition,pupation rate,and F3 egg hatch from AD4 were significantly larger than those from AD5.Moreover,as for M.basalis fed AD5,the durations of F2 2nd and 3rd larvae(9.00 d and 8.64 d)were significantly longer than those of F1 2nd and 3rd larvae(4.70 d and 4.92 d).The F1 oviposition period(31.57 d)was significantly longer than F2(20.80 d).The F2 female oviposition(189.20 egg/female)was significantly less than F1(307.14 egg/female).2 Effect of food and things on the back on larval cannibalism behavior was claritiedCannibalism behavior of 1st,2nd and 3rd larvae of M.basalis with or without food was observed.The cannibal would attack the victim with similar or smaller size,of which attacked time was 54.43 min.After that the cannibal may carry the shell residue of the victim on its back.Behavior haracteristic of larval cannibalism was observed with rice grain moth eggs as food and with cotton ball,paper scraps or lacewing puparium as things carrying on the back.The total cannibalic mortality with enough food was 32%~44%,while it significantly ascended without food(68%~76%).Different types of things carrying on the back of M.basalis did not affect the total cannibalic mortality.As for different days,there were significantly differences in cannibalic mortality per day by M.basalis carrying different types of things their back.The cannibalic mortality per day was the largest on Day 7 supplied with enough food,while on Day 3 supplied with no food.There were no significantly difference in larva duration supplied with enough food,9.18~10.10 d.There were significantly differences in larva longevity supplied with no food.When carrying pupa shell of green lacewing,it was shortest,3.20 d.3 Intraspecific competitions of M.basalis larvae supplied with food was clearedFor different rearing density,food types and amount,temperature and photoperiod,there were significantly differences in total cannibalic mortality of M.basalis supplied with food.As the rearing density,temperature or photoperiod increased,the total cannibalic mortality trended to increase,while it trended to decrease,along with the increasing food(rice grain moth egg,Lipaphis erysimi and artificial diet)amount.As the rearing density,temperature or photoperiod increased,the numbers of days in which larval cannibalism occurred trended to raise,while they descended along with the increasing amount of rice grain moth egg and L.erysimi.With regard to different days,there were significantly differences in cannibalic mortality per day under all different factors.The cannibalic mortality per day was the largest on Day 7 in most time.Cannibalism occurs until pupation.As for M.basalis fed different food amount of three kinds of food,emergence rate of individuals remaining after cannibalism was lowest when food amount was 0.03 g,while it was highest when food amount was 0.15 g.From 15~35?,as the temperature decreased,larva duration of remaining individuals gradually extended(7.60~35.40 d).M.basalis could not pupate at 15 and 35?.From 20~30?,as the temperature rose,pupa duration gradually shortened(10.00~21.00 d).Emergence rate was lowest at 15 and 35?(0%),while it was highest at 25?(63.33%).Female proportion was lowest at 20?(6.66%),while it wad highedt at 25?(63.33%).From 0L:24D~24L:0D photoperiod,as the illumination time extended,emergence rate of remaining individuals gradually increased(remaining individuals gradually).There were significantly differences in female proportion at different density and hunger time.4 Intraspecific competitions of M.basalis larvae supplied with no food was clarifiedWhen food was not supplied,the total cannibalic mortality trended to increase along with the increasing rearing density or temperature.0~24 h hunger time,40%~80% humity and 0L:24D~24L:0D photoperiod did not affect the total cannibalic mortality.Compared with food supplied,the total cannibalic mortalities were higher under different factors without food.As the rearing density or photoperiod increased,the numbers of days in which cannibalism occurred increased,while they decreased along with the increasing temperature or hunger time.With regard to different days,there were significantly differences in cannibalic mortality per day for different rearing density,hunger time,temperature,humidty and photoperiod.It was highest on Day 2-4.As for M.basalis of 0~24 h hunger time,larva longevity of remaining individuals in 0 h hunger time(4.60 d)was significantly longer than in 18 h(3.60 d)and 24 h(3.00 d).From 15~35?,as the temperature decreased,larva longevity of remaining individuals gradually extended.It was significantly longer at 15 ?(6.80 d)than at 20 ?(4.60 d),30 ?(4.00 d)and 35 ?(4.00 d). |
PDF Full Text Request