Antennal sensilla play an essential role in insect life because they receive environmental cues. Dioryctria rubella is an important pine pest in China, but information on the morphology and distribution of its sensilla is limited. To elucidate the mechanism of insect-plant chemical communication, we examined the insect antennae and sensilla by scanning electron microscopy. The results showed that the antennae of D. rubella were filiform and consisted of a basal scape, a pedicel, and a flagellum with tapered flagellomeres. We identified seven types of sensilla, including trichodea, coeloconica, auricillica, basiconica, styloconica (two subtypes), Böhm’s bristles, and squamiformia, all of which were distributed on the antennae of both sexes. Nevertheless, some sensilla exhibited various degrees of sexual dimorphism; for instance, sensilla trichodea, squamiformia, and basiconica were more abundant in males than in females. Many pores were observed on the surface of the cuticular wall in sensilla trichodea and auricillica, and their biological function may be related to olfaction. This study presented a thorough inventory of sensilla on the antennae of D. rubella and laid a solid foundation for future functional studies.

Monolepta signata is a polyphagous and highly destructive agricultural pest, currently only distributed in Asia. In its place of origin, it poses a serious threat to important economic crops, for instance, maize (Zea mays L.) and cotton (Gossypium hirsutum L.). Based on morphological and molecular data research, it has been found that M. quadriguttata (Motschulsky), M. hieroglyphica (Motschulsky), and M. signata are actually the same species. This discovery means that the range of this pest will expand, and it also increases the risk of it spreading to non-native areas worldwide. It is crucial for global agricultural production to understand which countries and regions are susceptible to invasion by M. signata and to formulate corresponding prevention, control, and monitoring strategies. This study uses the maximum entropy model, combined with bioclimatic variables and elevation, to predict the potentially suitable areas and diffusion patterns of M. signata worldwide. The results indicate that in its suitable area, M. signata is mainly affected by three key climatic factors: Precipitation of Wettest Month (bio13), Mean Temperature of Warmest Quarter (bio10), and Temperature Seasonality (bio4). Under the current status, the total suitable region of M. signata is 252,276.71 × 10⁴ km². In addition to its native Asia, this pest has potentially suitable areas in Oceania, South America, North America, and Africa. In the future, with climate change, the suitable area of M. signata will expand to high-latitude areas and inland areas. This study found that by the 2070s, under the SSP5-8.5 climate scenario, the change in the potentially suitable area of this insect is the largest. By identifying the potentially suitable areas and key climatic factors of M. signata, we can provide theoretical and technical support to the government, enabling them to more effectively formulate strategies to deal with the spread, outbreak, and invasion of M. signata.