| Phenacoccus solenopsis Tinsley was a new invasive pest in China,has widely host range,which caused serious damages on cotton,vegetables,garden crops and so on.P.solenopsis has a high reproduction,overlapping generation seriously,spread rapidly and has a great potential happen area in our country,a serious threat to agricultural production especially of cotton production.Our studies researched the sexual selection and diel mating rhythm,preliminary analyze the volatile components of 4-day-old female adults by GC-MS,identified 6 possible components that can make the antenna electroantennogram response of adult male by GC-EAD,EAG and Y-tube olfactometer were used to measure the electrophysiological and behavioral responses of P.solenopsis adults.And we also researched the types,morphology and distribution of sensilla on the antenna by scanning electron microscopy.The main results as follows: 1.The sexual selection and diel mating rhythm of P.solenopsis adults.The results indicated that 4-day-old virgin female adults were significantly more activities to males than the 3rd-instar nymphs and mated female adults.The mating peak time was 7:00-9:00 am.Male adults have a significant preference to 4-day-old virgin female adults,and the mating activity occurs in the morning,suggesting that female adults release significant amount of sex pheromone at 7:00-9:00 am.2.Analysed and identified the volatile components of 4-day-old female adults by GC-MS and GC-EAD.In this study,headspace volatiles from 4-day-old virgin female adults of cotton mealybug,P.solenopsis were analysed by GC-MS and GC-EAD techniques.Analysed by GC-MS,we abtained 2,2,3-trichloro-propanenitrile,1-chloro-1,2,3-Butatriene,Isophthalaldehyde,1R-alpha.-Pinene,2-chloro-2-methyl-Propanal etc.about 35 compounds.Compared the results of GC-MS and GC-EAD,identified 6 components that can make the antenna electroantennogram response of adult male of cotton mealybugs,hexanal,Z-3-haxenol,α-pinene,β-pinene,myrcene,E-2-hexenal.3.Electroantennogram response of adult male to 6 components standard compounds by electroantennogram(EAG).We settled different concentrations solution of standard compounds of these components,10μg /μl,1μg /μl and 0.1μg /μl.The results indicated that antenna EAG response of the concentration gradient of the 6 compounds solution were significantly higher than control,methylene chloride,and was positively related with concentration.Male antenna EAG response to myrcene was the most significant at 10μg /μl,EAG response value was 1.69±0.04 m V,when the concertration was 1μg /μl,the most significant response was Z-3-haxenol,EAG response value 0.99±0.03 m V,when at 0.1μg /μl,the most significant response was hexanal and α-pinene,EAG response value was 0.60±0.04 m V,0.55±0.03 m V respectively.4.Behavioral bioassays of electrophysiology active compounds.Behavioral bioassays of adult males of P.solenopsis to the 6 active standard compounds by Y-tube olfactometer.When compared with control,methylene chloride,both genders of cotton mealybugs adults showed a significantly repellency for Z-3-haxenol at 10μg /μl and preference for myrcene,males showed significantly repellency for E-2-hexenal.α-pinene,β-pinene and hexanal showed significantly attractiveness to the female adults.Except E-2-hexenal,females also showed preference for the other 5 compounds at 1μg /μl and 0.1μg /μl respectively.Males showed preference for Z-3-haxenol and myrcene at 1μg /μl and 0.1μg /μl respectively,0.1μg /μl of E-2-hexenal had a repellence for males.5.The ultrastructure of sensilla on the antenna of male adults.We examined the external morphology of the antennal sensilla of male by using scanning electron microscopy(SEM).The results indicated that three morphologically sensillar types were found and described on the antenna of male P.solenopsis,trichodea sensilla,basiconca sensilla and insegmental sensilla,then every segment of antenna has differences between quantity and length. |
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