Morphology Of Antennal Sensilla And Compound Eyes Of 86 Species Of Ants(Hymenoptera:Formicidae)

The antennae and compound eyes of insects are the main organs for sensing external information,which play an important role in perceiving external objects,feeding,avoiding enemies,determining the direction of movement and so on.Ants are common social insects.However,the morphological characteristics of antennal sensilla and compound eyes of a large number of ants are still poorly known.In this study,the antennal sensilla and compound eyes of 86 species of ants belonging to 53 genera of 10 subfamilies were scanned by scanning electron microscope,focusing on the type,distribution and number of antennal sensilla of each species,as well as the morphology of compound eyes.The differences of antennal sensilla were analyzed among subfamilies and genera,and cluster analysis conducted based on the types and numbers of antennal sensilla.In addition,All types of antennal sensilla were calibrated on corresponding branches of existing molecular phylogenetic trees to explore the significance of antennal sensilla of ants in classification and phylogenetic evolution.The results are as follows:(1)There are 28 types and subtypes of antennal sensilla in 86 species of ants,including sensilla trichodea(11 subtypes),sensilla chaetica(4 subtypes),sensilla basiconica(4 subtypes),sensilla trichodea curvata(3 subtypes),sensilla campaniformia,sensilla cavity,sensilla ampullaceal,sensilla coelocapitular,sensilla placoclea and B(?)hm bristles,respectively.Among them,sensilla trichodea are widely distributed in all parts of the antennae,while other types of sensilla are mostly distributed in the antennal flagellum.(2)The species and number of antennal sensilla are often different among subfamilies and genera,suggestion that which has some referenced value in classification of ants.The number of sensilla trichodea,sensilla trichodea curvata and B(?)hm bristles can be used as a taxonomic index for different subfamilies of Formicidae,and sensilla trichodea curvata can be used as a classification index among genera of Ponerinae.However,other feelings in other subfamilies are not reflected in their taxonomic significance.For example,the sensilla ampullacea of Myrmicinae,and the sensilla trichodea,sensilla chaetica,sensilla basiconica and sensilla cavity of Formicinae.(3)Cluster analysis showed that there were differences of antennal sensilla among subfamilies and genera,but the similarity among genera was not perfectly consistent with previous phylogenetic results.sensilla trichodea and sensilla chaetica are common in various subfamilies,which can be regarded as relatively primitive types,and some antennal sensilla have an independent evolution process.Further research is needed to determine which antennal sensilla can reflect the phylogenetic relationship.(4)The compound eyes of the usually primitive species(such as the Leptanillinae,Amblyoponinae and Proceratiinae)are relatively degraded,and the number of ommatidia more small or absent.The compound eyes of arboreal and nocturnal species is significantly larger and visual ability better than that of soil and surface life.The difference in external characteristics of compound eyes is the result of ants adapting to the living environment.