Morphology and Distribution of the Antennal Sensilla of Two Natural Enemies, Orius maxidentex and Orius minutus (Hemiptera: Anthocoridae)

The flower bugs, Orius maxidentex Ghauri and Orius minutus (Linnaeus), are important natural enemies of agricultural pests such as thrips and aphids. Insect olfactory systems play an important role in chemical communication, aiding them in locating host or prey habitats. To gain a deeper understanding of the role that sensory organs play in the biological behaviors of these flower bugs, the external structures of antennae and antennal sensilla were demonstrated using scanning electron microscopy (SEM). The antennae of the two species are linear in shape and consist of scape, pedicel, and two flagellomeres. The antennae of O. maxidentex were shorter compared to those of O. minutus . Additionally, the total length of the male antennae was longer than that of the female antennae in both species. Four types and four subtypes of antennal sensilla were documented in both species, including sensilla trichodea (ST I and ST II), sensilla chaetica (SCh I and SCh II), sensilla basiconica (SB), and sensilla campaniformia (SCa). Sexual dimorphism was not observed in the type and distribution of antennal sensilla but existed in the abundance of sensilla basiconica. Our findings provide important insights for future studies on defining the olfactory function of flower bug antennae using electrophysiological methods, especially in the heat‐resisting species O. maxidentex .