Establishiment Of Eriosoma Lanigerum Exprimenttal Population

Under controlled conditions,1,3,5,10,15,20and25woolly apple aphid (Eriosomalanigerum) were inoculated in three-year old Chang-fu2nd apple seedlings. Following thedistribution, colonization and population dynamic of aphid in seedlings were observed untilthe establishment of population. The preference of which parts in seedlings aphid liking tocolonization and effect of aphid inoculation in different parts of seedlings and different initialamount were analyzed. Also numbers of aphid reproduction per day was tested. The results asfollow:1. The regularity of aphid reproduction per dayIn the new environment, woolly apple aphid reproduction mainly happened during theday. There are four reproduction peaks in one day,3:00,11:00,17:00and21:00. Statisticsshow that it produced the most aphids at11:00, the number of production aphids daytimemuch more than that in the night, inferred that it prefers to producing aphids during the day.The light may have important influence on reproducing behavior.2. Choice of settling positionAfter inoculated in a new apple seedling, our experiment result reveals that less than5aphid could not success settled in host. This proves that settle is difficult for experimentconditions. Through the process of migration, lots of aphids were lost and the rate reached61.18%. Therefore, we inferred that the conditions of artificial inoculation may be differentsignificantly with the nature conditions in aphid population establishment.When the initial positioning, the population distribution was gradually smaller as thesequence of axillaries>stems>leaves; When repositioning, although leaves easy-to-suckingand feeding, because of nutritional reasons and being vulnerable to be impacted by the wind,were not suitable for the survival of groups of woolly apple aphid.3. The regularity of colonizationRespectively,15female adult aphids were infected at Flushe, trunk, brunche of the appleseedlings, the Statistical data show that the setting and breeding situation of Eriosoma lanigerum in three pick parts are different. At the same period of time, the amount of thesurviving adults and nymphs arranged for: flushe>trunk>brunch, and the differences betweenflushes and the other two parts reached a significant level, which indicated that under the testconditions, the flushe is more conducive to the survival and reproduction of Eriosomalanigerum.Under strict laboratory controlling conditions, each dwarf apple tree was infected with1,3,5,10,15,20or25aphids. The dispersal process and population dynamics duringcolonization were recorded. In all treatments, aphids could successfully survive about1to3aphids except1and3aphids per plant and there was a significant linear correlation betweenthe number of initial aphids and the time of the population reached Maximum. Continuousrainy weather had significantly inhibitory effect on population growth. The possibility ofsuccessful localization was higher when per plant was infected with more than15adultaphids, the same as stability of the population growth, but in a limited number of resourceunits, too much aphids should not be infected.Under suitable conditions, the rate of the woolly apple aphid from individualdevelopment to population faster, it was difficult to eradicate them when established a stablepopulation. Temperature and humidity, food quality, original dominant species of the insectshave a major impact on its population. Therefore, coming up with the ecological controlmode about Eriosoma lanigerumin in our modern apple orchard from the systemmanagement and the analysis point of key points, is the key in the orchard management.