| The planthopper superfamily Fulgoroidea(Hemiptera: Auchenorrhyncha)is an important group of the Auchenorrhyncha within the Order Hemiptera.It includes 21 families and more than 13,000 species,distributed all over the world,many of them are economically significant pests of major agriculture and forestry.However,problems still exist in the phylogeny of Fulgoroidea and relationships between some families remain controversial so far.More evidence are still needed to deal with the phylogenetic relationships of this group.In the present study,the comparative morphology and ultrastructure of the mouthparts,antenna and tegula of 61 species in 52 genera representing all lineages of Fulgoroidea,along with 5out-group representatives of Cercopoidea,Membracoidea,Pyrrhocoridea and Pentatomidea were studied by mean scanning electron microscope.Based on theirs morphology,function and phylogeny implication were discussed.The results are as follows:1.Mouthparts.The mouthparts of Hemiptera is typical piercing-sucking type,consisting of a tube-like structure including the labrum,labium and a stylet fascicle comprising two mandibular and two maxillary stylets.The segmented labium has a deep longitudinal groove on the ventral surface,within which lies the stylet fascicle.The labium is mainly covered with sensilla chaetica,symmetrically scattered on either side of the labial groove but some on the distal end.The labrum attaches to the anterior margin of the anteclypeus and overlays the part of the labial groove.The mandibular stylets are abutted on each lateral side of the maxillary stylets,the maxillary stylets interlocked to form a larger food canal and a smaller salivary canal,and the most noticeable feature of the mandibular stylet is the prominences on its tip,each maxilla or mandible bears dendritic canal.In Hemiptera,morphology of the mouthpart varied in different suborders,families and genera,mainly reflected in the distribution of cuticular processes and wrinkle or sensilla on labrum;the types,number,form and position of sensilla on labium and on the labial tip;the number and form of protuberances on mandibular stylet,the internal connecting systems of the two maxillary stylets and number of the dendritic canal in stylets.(1)In Fulgoroidea,the labrum simple,generally overlays the labial groove of the labial segments;some groups have flat lateral protrusion of labrum or few sensilla chaetica on the surface of labrum.Labium unusually have three segments,sometimes four or five-segmented.Subapical labial sensilla present in all families,but the types,number and position of the sensilla varied in different families.The labial tip have two dorsal sensory fields and two ventral sensory fields,the types,number and position of the sensilla varied in different groups.The mandible styles bear a few unapparent protuberances distally,with three locking mechanisms of maxillae and mandibles,two dendritic canals in each maxilla and one in each mandible.(2)In Membracoidea,labium three-segmented,with five teeth on the mandibles distally.The labial tip with two lateral lobes divided into anterior sensory fields and posterior sensory fields,each anterior sensory field possesses one sensillum chaetica and eight different sensilla basiconica;posterior sensory fields with two sensilla chaetica and two sensilla basiconica(3)In Cercopoidea,labium three-segmented,the mandibles serrated ventrally,with five teeth distally.The labial tip with two lateral lobes divided into anterior sensory fields and posterior sensory fields,the types,number and position of the sensilla on the sensory fields varied in different groups.(4)In Heteroptera,labium four-segmented,with numerous sensilla chaetica and sensilla basiconica on surface,the subtypes,number and position of sensilla basiconica different between Pyrrhocoroidea and Pentatomoidea.The mandibular stylet toothed at tip and a series of scale-like projections.Apex of the labium with two lateral lobes and an apical plate,the types,number and position of sensilla on each lateral lobe and apical plate varied between Pyrrhocoroidea and Pentatomoidea.2.Antennae: Antenna of hemipterans comprise scape,pedicel and flagellum.In Fulgoroidea and Cercopoidea,flagellum long,bristle-like,with a swollen sensory region near its junction with the pedicel,in Membracoidea,flagellum had many flagellomeres,in Pyrrhocoroidea of Heteroptera,the flagellomeres has two flagella subunits,but Pentatomoidea has three subunits.(1)In Fulgoroidea,seven types of sensilla were found on antennomeres,randomly distributed on surface.A B(?)hm bristle,a sensillum campaniformia and sensilla chaetica were found on the scape;pedicel possesses a sensilla campaniformia,sensilla chaetica,sensilla trichoideum and different forms of plaque organs;three sensilla basiconicum or a cuticular spur and Bourgoin’s organ were observed on the basal bulb of the flagellum.Plaque organs have been classified into 5 main morphological types,including the setae-like projected plate,the flattened star-shaped plate,the crenellated plate,the folded flattened plate and the circular flattened plate.Different groups have different types of plaque organs,and the shape of the same type of plate organs varied as well in different groups.The wall around the aperture of Bourgoin’s organ varied in different groups.(2)In Membracoidea,the scape and pedicel short and wide,covered by numberous cuticular scales,few sensilla chaeticum were sporadically on the distal pedicel.Four sensilla coeloconica and two sensilla chaeticum were observed on the basal flagellum.(3)In Cercopoidea,the scape and pedicel short,the scape covered with numerous cuticular processes and a few sensilla chaeticum and sensilla basiconicum.The pedicel covered by numerous cuticular scales and few sensilla chaeticum,pedicel apically with few sensilla coeloconica at the sunk radular surface.Flagellum has one big sensillum basiconica and a lot of sensilla coeloconica on the expanded base.(4)In Heteroptera,in Pyrrhocoridea and Pentatomidea,four types of sensilla were observed,mainly distributed on flagellum.B(?)hm bristles only on the base of scape,sensilla basiconca mainly on scape and flagellum.Pyrrhocoridea with large number of sensillum chaeticum mainly distributed on scape and pedicel;Pentatomidea with greatest number of sensilla trichoideum mainly found on the last two flagellomeres.3.Tegula.In Fulgoroidea,tegula is composed of sclerite and arm,morphologically varied in different families,including the shape of the sclerite,arm and angle between the arm and sclerite.Most fulgoroids with samller sclerite,a triangular and membranous arm paralleled to the sclerite.But ricaniid species with ossific and thick sclerite and arm,and the sclerite vertical to arm.4.Phylogenetic analyses based on the morphological data were studied.The results support the monophyly of Fulgoroidea,the family Derbidae is a relatively ancient in Fulgoroidea;and Dictyopharidae is monophyletic.Fulgoridae and Lophopidae were also placed as a sister group,Eurybrachidae as a sister to Fulgoridae + Lophopidae,Eurybrachidae diverged much early.Species in Achilidae were not grouped together and this family is paraphyletic.Tettigometridae near the top of the cladogram.The monophyly of the family Flatidae and Ricaniidae,and the sister relationship between the two families were strongly supported;the family Ricaniidae represent the most evolved lineage of Fulgoroidea. |
