biostudies-literatureDong ZNational Natural Science Foundation of Chinae0241115https://www.ebi.ac.uk/biostudies/studies/S-EPMC7598455biostudies-literatureUnknown15(10)Allotraeus asiaticus Schwarzer and Callidiellum villosulum Fairmaire are repeatedly intercepted in wood and wood products all over the world. As two common stem borers of Cunninghamia lanceolata (Lambert) Hooker, to further understanding of the differences in their living habits, behaviors and the mechanism of insect-host chemical communication, we observed the external morphology, number and distribution of antennal sensilla of A. asiaticus and C. villosulum with scanning electron microscopy (SEM), respectively. The results showed that 1st-5th subsegments of the flagellum are spined endoapically in A. asiaticus which is different from the previous report (1st-3rd of the flagellomere). Meanwhile, there were five subsegments on the flagellum of C. villosulum that were clearly specialized asPloS oneFirst description and comparison of the morphological and ultramicro characteristics of the antennal sensilla of two fir longhorn beetles.PMC759845531660626Dou FYang YZheng XLu WHuang ZZhang YDong ZWickham JDTang RWang XfalseFirst description and comparison of the morphological and ultramicro characteristics of the antennal sensilla of two fir longhorn beetles.Allotraeus asiaticus Schwarzer and Callidiellum villosulum Fairmaire are repeatedly intercepted in wood and wood products all over the world. As two common stem borers of Cunninghamia lanceolata (Lambert) Hooker, to further understanding of the differences in their living habits, behaviors and the mechanism of insect-host chemical communication, we observed the external morphology, number and distribution of antennal sensilla of A. asiaticus and C. villosulum with scanning electron microscopy (SEM), respectively. The results showed that 1st-5th subsegments of the flagellum are spined endoapically in A. asiaticus which is different from the previous report (1st-3rd of the flagellomere). Meanwhile, there were five subsegments on the flagellum of C. villosulum that were clearly specialized as2020-01-01T00:00:00Z20202025-04-19T13:35:17.951Z2020-11-08T09:42:39ZS-EPMC75984553312538010.1371/journal.pone.0241115