Morphology And Systematics Of The Subfamily Plusiinae (Lepidoptera:Noctuidae) From China

The looper moths Subfamily Plusiinae(Lepidoptera: Noctuidae)contain numerous species of agricultural and forestry importance.Plusiinae can be easily distinguished from other subfamilies of Noctuidae by the following characters: golden spots or silvery stigma on the forewing,lashed eyes,and large scale tufts on the thorax,and the larvae bearing two pairs of prolegs on abdominal segments V and VI.However,the systematics of Plusiinae is still in chaos to date,and it is urgently necessary to conduct the taxonomic and phylogenitic studies of the subfamily.We compared the morphology of proboscis sensilla in 19 representive species of Plusiinae and four of Noctuinae using scanning electron microscopy.The results showed that sensilla chaetica,sensilla basiconica,sensilla styloconica,and sensilla coeloconica are present on the proboscis and only the proximal region is fluted with the cuticular processes in Plusiinae.While in Noctuinae,only sensilla chaetica,sensilla basiconica,and sensilla styloconica are present on the proboscis,and the whole proboscis is fluted with cuticular processes.The differences of proboscis sensilla between Plusiinae and Noctuinae mainly reflected in the number and distribution of sensilla chaetica,number and shape of sensilla styloconica,and the types of sensilla that occur on the tip region of the proboscis.There was no significant difference within the subfamily.The variation of sensilla types,the variation of the distribution of sensilla chaetica,and the variation of shape and number of sensilla styloconica could be used as characters for taxonomy of subfamily in Noctuidae.The scale ultrastructure of the forewing of Extremoplusia megaloba(Hampson,1912)and Thysanoplusia intermixta Thysanoplusia intermixta(Warren,1913)were compared using field emission electron microscopy,and found that the two species bear five and four types of scales,respectively.The length and width of the scales,and the numbers of holes between ridges and cross are different.There are few windows in the silvery area of the forewing of E.megaloba,and in the golden spots of T.intermixta.The windows are extremely small or even vestigial.The relationship between scale structure and color was discussed briefly.The morphologies of the eggs and larvae of Autogrpha nigrisigna(Walker,[1858])are described and illustrated in detail using light and scanning electron microscopy,and crochets and chaetotaxy are illustrated.According to the study,79 species in three tribes and 27 genera of Plusiinae are described as a comprehensive study of the fauna of China.Keys are given to all tribes,genera,and species included.Two species are recorded from China for the first time: Euchalcia herrichi(Staudinger,1861)n.rec.and Euchalcia cuprescens Dufay,1965 n.rec.We analyzed the phylogenetic relationships among 30 species of 16 genera in Plusiinae using maximum likelihood and Bayesian inference based on two mitochondrial(cox1,cox2)and three nuclear(RpS5,EF-1?,28 s rDNA))gene fragments with Eulepidotis rectimargo(Guenée,1852)and Miniodes phaeosomaas Hampson,1913 as outgroups.The results showed that the subfamily is monophyletic.The tribe Abrostolini is the most primitive of the three tribes,and is a sister group of Argyrogrammatini + Plusiini.The genera Anadevidia Kostrowicki and Extremoplusia Ronkay should be transferred into the tribe Plusiini.The tribe Argyrogrammatini is a sister group of Plusiini.The genus Diachrysia Hübner is a monophyletic group.The subtribes Plusina and Euchalaiina are both monophyletic groups.Autographa Boisduval is a sister group of Syngrapha Hübner.Lamprotes Reichenbach is a sister group of Polychrysia Hübner.