海南芒果主要害虫及其重要天敌种群消长记述

DYNAMICS OF KEY PESTS ON MANGO AND THEIR NATURAL ENEMIES IN HAINAN ISLAND

芒果片角叶蝉(Idiocerus niveosparsus Leth.)及片角叶蝉(Idiocerus sp.)、横线尾夜蛾(Chlumetia transversa Walker)、重尾夜蛾〔Bombotelia jocosatrix(Guen)〕、脊胸天牛(Rhytidodera bowringii White)和桔小实蝇(Strumeta ferruginea dorsalisHendel)是海南岛芒果的主要害虫。在岛西北部,芒果片角叶蝉年发生7—9代,有两个虫口高峰期。第一高峰期发生于2—3月,恰与芒果花期和幼果期吻合,对当年产量构成很大威胁;第二个高峰期发生于7—10月,但经济重要性小。横线尾夜蛾年发生8—10代,12月至翌年1月为第一个虫口高峰期,5—6月和9—10月也各有一高峰期。重尾夜蛾年发生7—8代,第一、二代发生在芒果花期,严重为害花芽,另两个虫口高峰分别出现在夏、秋梢抽发之际。脊胸天牛年发生一代,4—5月是其成虫羽化和产卵高峰期。桔小实蝇损害成熱期(5—7月)芒果,6—8月是其成虫虫口高峰期。寄生真菌是芒果叶蝉类害虫的重要天敌,蜘蛛是芒果害虫的重要捕食性天敌,它们对控制芒果害虫虫口有一定的作用。

The leaf hoppers(Idiocerus spp.),the noctuids(Chlumetia transversa,Bombo-telia jocosatrix),the branch borer(Rhytidodera bowringii)and the fruitfly(Stru-meta f,dorsalis)are the key pests on mango in Hainan.Under the natural condi-tion in western Hainan Island,Idiocerus niveosparsus takes place 7—9generationsin a year.There are two peak periods of population.The first peak occurs duringFebruary to March,coinciding with the flowering and fruiting season and thusthreatening the yield of the year.The second peak appears during July to October,which is of little economic importance.C.transversa propagates 8—10 generationsin a year.The period of December to January sees the first population peak.Thereare also population peaks during May to June and September to October,respec-tively.B.jocosatrix occurs 7—8 generations in a year.The first and second gene-rations take place during flowering season,causing serious damage on flower buds.The other two peaks appear in summer and autumn respectively,to attack the newshoots.R.bowringii has one generation in a year.The peak period of emergenceand oviposition in adults is during April to May.Strumeta f.dorsalis damagesmango fruits during their ripening season between May—July although the popula-tion peak of the fruitfly occurs from June to August.The dynamics of the parasitic fungus on the leaf-hoppers as well as the relationbetween the parasite and its host are discussed.Besides,the dynamics of the majorpredators spiders on mango pests is also mentioned.