The vitellogenin receptor (VgR) belongs to the low-density lipoprotein receptor (LDLR) family, responsible for mediating the endocytosis of vitellogenin (Vg) into the ovaries to promote ovarian growth and oviposition. Here, we cloned and measured VgR gene expression characteristics in the bumblebee Bombus lantschouensis. RNA interference was used to validate VgR function. The results showed that the full length of the BLVgR cDNA was 5519 bp, which included a 5280 bp open reading frame encoding 1759 amino acids (AAs). Sequence alignment revealed that the protein contained 12 LDLa, 5 EGF, 2 EGF-CA and 10 LY domains. Phylogenetic analysis showed that BLVgR and the VgR of Bombus terrestris clustered together and the tree of bumblebees (Bombus) appeared as one clade next to honeybees (Apis). Transcript expression analysis showed that BLVgR was expressed in all tested tissues and showed the highest abundance in the ovaries. BLVgR expression was present in all developmental stages. However, the expression level in larvae was extremely low. In addition, the expression of BLVgR was significantly upregulated after egg laying in both workers and queens. In new emerging workers injected with 5 µg of VgR dsRNA, the expression level of BLVgR was 4-fold lower than that in the GFP dsRNA-injected group after 72 h. Furthermore, BLVgR silencing significantly reduced the number of eggs laid (3.67 ± 1.96 eggs) and delayed the first egg-laying time (16.31 ± 2.07 days) in worker microcolonies when compared to dsGFP (37.31 ± 4.09 eggs, 8.15 ± 0.22 days) and DEPC-treated water injected controls (16.42 ± 2.24 eggs, 10.00 ± 0.37 days). In conclusion, the BLVgR gene and its reproductive function were explored in the bumblebee B. lantschouensis. This gene plays an important role in egg laying time and egg number.

The honeybee Apis cerana plays a crucial role as a pollinator, contributing significantly to biodiversity and supporting ecological processes

The tea leaf beetle Basilepta melanopus is a devastating leaf-feeding pest of tea plants, with its infestation area and damage severity in Chinese tea plantations continuously increasing. Characterizing the morphology and distribution of sensilla provides a morphological basis for understanding the behavioral mechanisms underlying host recognition, mate localization, and environmental perception of this pest. In this study, the morphology, ultrastructural characteristics, distribution and sexual dimorphism of sensilla on antennae, mouthparts, legs, and external genitalia of B. melanopus adults were examined by stereomicroscopy and scanning electron microscopy (SEM). Nine types and thirty-nine subtypes of sensilla were observed. These include various types on the antennae, including Böhm bristles, sensilla chaetica, sensilla trichodea, sensilla basiconica, sensilla auricillica, sensilla coeloconica, and sensillar pits, and many subtypes. The two types of sensilla unique to the mouthparts are sensilla styloconica and sensilla campaniformia. Sensilla chaetica and sensilla trichodea are also found on the tarsi. In addition, sensilla trichodea and sensilla basiconica were identified on the external genitalia of the female insect. On the male external genitalia, four types of sensilla were observed: sensilla trichodea, sensilla chaetica, sensilla basiconica, and sensilla coeloconica. There were also differences in the number and size of sensilla between males and females. This study investigated the relationship between the sensilla of B. melanopus and its key behavioral activities, namely feeding and oviposition, through detailed morphological observations and systematic analysis of these sensory structures. The findings provide a conceptual framework and offer novel perspectives for future research on the behavioral ecology and integrated management of this species.