Reasearches On Insect Population Dynamics And Community Characteristics On Pleurotus Ostreatus And Intrinsic Ecological Characteristics Of Lycoriella Pleuroti Yang Et Zhang

The population dynamics and main insect community characteristics on oyster mushroom, Pleurotus ostreatus, the trapping effectiveness of different colored sticky cards were studied to lay theoretical foundation for forecasting and integrated control of pests on Pleurotus ostreatus.The biological and ecological characteristics of Lycoriella pleuroti, a dominant pest, were analyzed using the age-stage, two-sex life table to make clear the intrinsic ecological characteristics for its serious damage.The eighteen species of insects on Pleurotus ostreatus belonging to five Orders, thirteen families were found in our investigation, among which there were sixteen species of pests belonging to four Orders, eleven families and some spiders as natural enemies. These pests included Collembola, Coleoptera, Diptera and Lepidoptera. The major pests were mosquitoes and flies in Diptera. Lycoriella pleuroti was the dominant pest.The investigation had two periods. Firstly, we investigated low and median temperature-cultivated mushroom varieties from February24th to May12th, and secondly investigated high temperature-tolerated mushroom from June5th to September25th. The number of pests peaked in spring （April and May） and autumn （September）. The population dynamics of natural enemies synchronized main pests. The population dynamics of the main insects on Pleurotus ostreatus was related to the temperature, surrounding environment and manmade factor.The trapping effectiveness of ten types of colored sticky cards including dark-blue, light-blue, red, pink, yellow, white, purple, gray, black and green ones for different pests were investigated. The yellow cards displayed the best efficacy for trapping Sciaridae. Generally, yellow, green and white ones had better efficacy for trapping lower Diptera including Sciaridae, Cecidomiidae, Chironomidae, Mycetophilidae, Tipulidae, Scatopsidae. The flies significantly preferred dark-blue cards to others. The number of trapping pests on the edge of sticky cards was obviously higher than that in the middle part.The mean developmental times of Lycoriella pleuroti were37.55,25.62,24.14,20.29and15.98days, respectively at15℃,20℃,23℃,25℃and28℃. The developmental periods of each stage shortened as the temperature rose. The developmental rates of every stage related linearly to different temperatures significantly. The eggs could not develop normally at30℃. The developmental times of females were longer than males in preadult stage. The developmental threshold temperature and effective accumulative temperature of four stages were researched and those of the whole generation were7.72±2.22℃and320.32±47.01degree-days, respectively.The mortality of Lycoriella pleuroti was17.25%、12.25%、13.28%.12.66%and17.75%, respectively at15℃,20℃,23℃,25℃and28℃. The egg stage had the highest mortality, then the beginning of larva stage, and the survival rate in pupa stage was highest, so egg was a key weak stage.The intrinsic ecological characteristics of Lycoriella pleuroti were analyzed using the age-stage, two-sex life table. At15℃,20℃,23℃,25℃and28℃the mean fecundity was89.39,100.23,111.23,113.62and108.15eggs/female in sequence. The ratio of female to male related with the size of laboratory population sample was1:0.67,1:0.83,1:0.84,1:0.79and1:0.75successively. Total preoviposition period of female counted from birth （TPOP） was37.08,24.91,23.31,18.03and14.56days in turn. The intrinsic rate of increase （r） was0.0997,0.1509,0.1646,0.2132and0.2593d^-1, respectively and increased when temperature rose. The net reproduction rate （R₀） was44.25,48.11,52.37,55.37and50.83in sequence. The mean generation time （T） was38.00,25.67,24.04,18.82and15.15day successively. The life expectancy of a newborn egg was also the finite rate of increase （λ）, and was1.1049,1.1629,1.1790,1.2377and1.2961d^-1, respectively. The gross reproduction rate （GRR） reached maximum value203.37at23℃.