Studies On Biological Characteristics And Integrated Control Techniques Of Lepidosaphes Sp.in Xiamen

Since 2015,the coastal Wetland Park under the construction of Xiamen's Xiatanwei has produced a large area of triennial mangrove pest outbreaks,causing serious harm.This article observed and analyzed the biological characteristics of pests causing serious harm and classified as Lepidosaphes sp.,which is a new pest in mangrove;by investigating the characteristics of population dynamic change,we knew the outbreak rule and analyzed the influencing factors with habitat and meteorological factors;the article used biological agents and chemical agents to study the prevention and treatment of the pest,and preliminarily established a comprehensive control method.The main results are as follows:(1)L.sp.is parasitic only on the leaves of Kandelia obovata in mangrove,which can parasitize on leaves and branches in lab feeding,Its testa in mangrove is thicker than the testa raised indoors.L.sp..(2)L.sp.takes place 9 generation every year in Xiamen and shows severe generation overlap,with no clear sign of over-wintering.The developmental period of L.sp.is short.And it is bisexual and the annual average fecundity is 35 eggs each female.The individual development process of female insect:egg?first instar nymph?second instar nymph?female adult.And the individual development process of male insect:egg?first instar nymph?second instar nymph?prepupa?pupa?male adult.(3)The 2017 survey showed that the population density of L.sp.was the highest in October and the lowest in September.The population density of L.sp.on the leaves and on the back of Kandelia obovata showed a significant difference.And the population density of L.sp.in middle tidal flat and in outer tidal flat showed a significant difference.(4)There was a significant negative correlation between population density of L.sp.in outer tide flat and temperature?height of high tide,so did population density of L.sp.in middle outer tide flat.There was no significant correlation between the population density of L.sp.and meteorological factors and tidal factors in the shade mangrove on the middle tide flat.Totally,population density of L.sp.was significantly negatively correlated with monthly average temperature and monthly minimum relative humidity.(5)The result of the toxicity test of 7 kinds of insecticides to L.sp.showed the better effective of EnSpray,matrineb and thiamizine,which were effective to first instar nympha of L.sp..The synergistic mortality of the mixture of 9.9 mg/L EnSpray and 5 mg/L matrineb was the highest to first instar nymph in lab.The effect of 10 days after spraying 3 times was the best.(6)Two species of parasitoid wasps,both belong to the family Aphelinidae,were found,which is Aphytis sp.and Encarsia sp.,and the fomer was the dominant species.