| Peanuts are one of the important oil crops in the world and its main producing area is Shandong province.Peanut spider mite is important pest mites which can harm peanuts.Carmine spider mites occur widely in Shandong Province and its scale is so large.With the adjustment of planting structure,two-spotted spider mites have a significant upward tendency in recent years.Therefore,through exploring adaptive difference which Tetranychus urticae and Tetranychus cinnabarinus act on different peanut varieties and different host plants,the author compared the susceptibility differences which common acaricide acts on the two leaf mites.In order to screen anti mite peanut varieties mite and ease spider mite damage mitigation by reasonable crop layout,the author provides the basis for scientific control spider mites.The main results are as follows:1.By investigating the field system,Shandong peanut field cinnabarinus began in June;July and August are the damage peak and September is the late damage.The extent of victimization among peanut varieties were significantly different,where the Huayu24,634-2,the Feng6 flowers and the flower 17,328-1 suffer heavily and its average number of mite is above 30 mite leaf/pier;and varieties of 606,818 and KB008 leaves have fewer mites and its average leaf mites is 10-15/pier;other varieties of peanut is mediate.2.Laboratory test showed that different peanut varieties have a certain influence on the selectivity of spider mites,and these two species of mites have different tend to different peanut varieties.T.urticae has the highest selectance to the flowers 17 and the fenghua1 and the ratios were 22.08% and 18.20%;then it has a higher selectance to Huayu22 and Huayu24 and the ratios were 13.40% and 8.21%;the lowest selectance is to 6 and 818 and the ratios were only 3.03% and 3.89%.But carmine spider mite has significant tropism to the Fenghua5 and the flower 6 and the ratios were 26.37% and 23.45%;then followed by white sand and Huayu22 and the ratios were 9.60% and 9.22%;the lowest selectance is to 24 varieties of flowers and abundance of fenghua1 and the ratios were only 2% and 3%.Different peanut varieties have distinct effect on the growth and reproduction of two kinds of leaf mites live.Mite survival rate difference between these two spider mites is small,but large among varieties,including the survival rate of Tetranychus urticae in the Baisha,the Huayu24 and the Fenghua6 is about 90%;the survival rate in the full Fenghua5,606 and 634-2 is about 80%.The survival rate of carmine spider mite species in the Baisha,the Huayu24,the No.6,the fenghua5 and the 634-2 is about 90%;the survival rate on the 606 survival is only 77.7%.Two species of mites grew faster in the variety Huayu24,the 634-2 and the Baisha1016.The amount of the two-spotted mite infestation 20d3 varieties on spider mites were 106,101,97;the infestation on the cinnabarinus were 114,97,101;and the T.urticae on the 606 varieties of flowers and the abundance No.5 were only 84 and 82;the number of carmine spider mite was 70 and 78.The fertility difference between the same two leaf mites on peanut varieties is prominent and the fecundity of the carmine spider mite was significantly higher than the two-spotted spider mites.The carmine spider mite eggs on the white sand were 108,while the two-spotted spider mite was 95.The differences among peanut varieties are more obvious,of which the two-spotted spider mite eggs on the 24 is 109 and on the Floribunda 5 is 67;carmine spider mite fecundity accumulated Huayu24 up to 110 and 606 in a minimum of 76.Based on the result of the above analysis: the varity 606 and 818 is not conducive to the growth of varieties of spider mites and they belong to the anti-mite;KB008 and abundance spend 5 have certain resistance;varieties 634-2,Baisha1060,328-1,Fenghua1 and spent 22 are moderate resistance,but the 24 varieties of flowers,flowers 17 and Fenghua6 are sense mite species.These two mite-resistant peanut varieties also differ in resistance of peanut varieties.Two-spotted spider mite has a distinct tropism to flowers 17 and flowers 1;carmine spider mites tend to Fenghua5 and 6.These two species have small resistance trend difference to other small peanut varieties.3.Through two choice experiments of indoor two leaf mites to peanuts and eight kinds of host plant found that there are obvious differences between the two kinds of leaf mites.Among them we can know that the selectivity of the two-spotted spider mite is higher than cowpea and peanut peach and the selectivity rates are 91.66% and 61.76%;while among the other seven combinations and host plants of peanuts,peanut selectivity is high and the selection rates is above 60%;in the peanut-maize and peanuts-Apple group,peanut selectivity are 96.12% and 92.24%;compared with peanut,carmine spider mites prefer to select soybean,soybean selection rate is 79.6%,while in the peanut-cotton and peanuts–Apple,carmine spider mites prefer to choose a combination of peanuts and the selectivity was about 70%;the differences is smaller among the other six host plants peanut portfolio selection and the selectivity was about 50%.The results showed that among the host combinations which peanut as a control,the selectivities of two-spotted spider mite selectivity of cowpea and peach are strong.Carmine spider mites have obvious trends on soybean,and other host combination both leaf mites are showed obvious trend of peanut.The host plant has different effects to two kinds of leaf mites,population and fertility.The survival rates of 5d in peanut two species of mites are more than 90% and the survival rates of two-spotted spider mites on soybean was 77.5%,while the survival rates of the carmine spider mite was 100%.The differences between host plants are significant.The survival rates of two-spotted spider mites peanuts,potato,sweet potato and cotton are more than 90%,while the survival rates of soybeans and corn were only 77.5% and 72.5%;the survival rates of carmine spider mite on the peanut,soybean,potato,sweet potato were more than 90%,while the survival rates in corn and cotton were only 77.5% and 77%.The adaptability of peanut on these two kinds of spider mites are strong;the number of 20 d and two-spotted spider mites are up to 105 and the eggs are 104;carmine spider mites amount is 95 and the eggs are 92;the adaptability of cinnabar spider mites on soybean is also strong and the amount of mite 20 d reaches 95,and the cumulative spawn 94.The adaptability of potato,poor cotton,sweet potato and corn is poorer and the amount of mites 20 d respectively was 45,32,26 and 20,a total of 50 eggs were the following.The adaptability of two-spotted spider mites on potatoes and sweet potatoes are so strong;20 d mite volume reached 90 and 73,the cumulative spawning of 80 and 66 respectively,while fewer amounts of mites on corn and cotton,the amount of 20 d mites are 20 and 15,and the accumulative eggs are less than 20 grains.There are significant differences between peanut and other host plants.And the population size and fecundity of the two spider mites in corn and cotton are significantly lower than other hosts.Through comprehensive Selection rate,survival rate,population and reproductive four factors,the range of suitable hosts for the two-spotted spider mites are cowpea,peanut and peach;suitable host ranges of cinnabarinus are soybeans,potatoes and peanuts.4.By using insect immersion method to compare the virulence and the differences of the seven kinds of commonly used acaricide between the two adult mites and mite eggs,seven kinds of test agents on cinnabarinus adult and eggs virulence were more stronger than two-spotted spider mites,On Tetranychus urticae mites virulence Spirotetramat maximum(1.213mg/L)> Pyridaben(6.023mg/L)> Bifenazate(7.199mg/L)> Avermectin(10.901mg/L);Tetranychus cinnabarinus mites Avermectin highest Virulence(0.044mg/L)> Spirotetramat(0.049mg/L)>Pyridaben(1.056mg/L)> Bifenazate(1.875m/L);Spirotetramat and avermectin insects and spider mites are the two highest toxicity to kill eggs,two-spotted spider mite LC50 was 0.037mg/L and 0.04mg/L,Respectively,carmine spider mite LC50 were 0.005mg/L and 0.088mg/L,Etoxazole virulence followed,Pyridaben and Chlorfenapyr has a good ovicidal virulence.Spirotetramat and Avermectin for both the adult mites and mite eggs are good virulence. |
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