First record of bird and spider species preying on dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) in the Amazon Forest

Posted by
  First record of bird and spider species preying on dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) in the Amazon Forest Abstract Predator-prey relationships are critical for establishing trophic networks, but our understanding of these interactions is hindered by a lack of records in tropical rainforest ecosystems. Although literature indicates that dung beetles may be preyed by a wide range of animal species, surprisingly, there are no such antagonistic records between dung beetles and other species in the Amazon forest. The objective of this study is to present two records of such interactions in the Amazon, involving a bird and a spider species preying on dung beetles. The bird  Galbula albirostris  Latham, 1790 (Aves: Galbulidae) was observed feeding on a Deltochilini dung beetle (Coleoptera: Scarabaeidae) in a  terra firme  forest, while a  Canthidum  sp. was captured in a  Trichonephila  sp. (Araneae: Nephilidae) spider web on a...

Functional Study of Opsin Genes in Pardosa astrigera (Araneae: Lycosidae)

Posted by

 


Functional Study of Opsin Genes in Pardosa astrigera (Araneae: Lycosidae)

Abstract


Spiders are important predatory natural enemies in agricultural and forestry ecosystems, yet the role of vision in their predatory behavior remains unclear. In this study, we screened three opsin genes—corresponding to ultraviolet-sensitive and medium-to-long wavelength-sensitive opsins—from the transcriptome sequencing database of Pardosa astrigera. All three genes possess seven transmembrane topological structures and a lysine residue on the second transmembrane domain, which are typical characteristics of opsins. Using quantitative real-time PCR (RT-qPCR), we analyzed the expression patterns of these opsin genes in different tissues, developmental stages, and under the induction of light at three wavelengths. The results showed that all three opsin genes were significantly expressed in the cephalothorax and expressed across developmental stages with no significant differences. Under light induction, their relative expression first increased and then decreased in both male and female adult spiders. Subsequently, RNA interference (RNAi) was used to individually knock down each opsin gene, confirming their involvement in color vision. These results suggest that the three opsin genes are involved in spider vision, laying the foundation for further elucidating the role of vision in spider predation, and offering a new perspective for reducing the unintended killing of natural enemies by insect traps.

Zhai, S., Ren, B., Zhang, X., Shen, F., Ma, M., Li, X., & Li, R. (2025). Functional Study of Opsin Genes in Pardosa astrigera (Araneae: Lycosidae). Insects, 16(6), 595. https://doi.org/10.3390/insects16060595