Contribution of pitcher fragrance and fluid viscosity to high prey diversity in a Nepenthes carnivorous plant from Borneo

Journal of biosciences

David J Marshall²  Bruno Di Giusto²  Vladimir Grosbois¹  Laurence Gaume3³  Elodie Fargeas³ 

[1] Department of Biometry, CEFE-CNRS, 1919 route de Mende, F-34293 Montpellier cedex 5, France$$;Universiti Brunei Darussalam, Biology Department, Jalan Tungku Link, BE 1410 Gadong, Brunei Darussalam$$;Botanique et bioinformatique de l'architecture des plantes, UMR CNRS 5120, CIRAD - TA-51 / PS2, Boulevard de la Lironde, F-34398 Montpellier, cedex 5, France$$

关键词: Attraction;    carnivory;    digestive liquid;    insect capture;    Nepenthes rafflesiana;    pitcher plant;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Mechanisms that improve prey richness in carnivorous plants may involve three crucial phases of trapping: attraction, capture and retention. Nepenthes rafflesiana var. typica is an insectivorous pitcher plant that is widespread in northern Borneo. It exhibits ontogenetic pitcher dimorphism with the upper pitchers trapping more flying prey than the lower pitchers. While this difference in prey composition has been ascribed to differences in attraction, the contribution of capture and retention has been overlooked. This study focused on distinguishing between the prey trapping mechanisms, and assessing their relative contribution to prey diversity. Arthropod richness and diversity of both visitors and prey in the two types of pitchers were analysed to quantify the relative contribution of attraction to prey trapping. Rate of insect visits to the different pitcher parts and the presence or absence of a sweet fragrance was recorded to clarify the origin and mechanism of attraction. The mechanism of retention was studied by insect bioassays and measurements of fluid viscosity. Nepenthes rafflesiana was found to trap a broader prey spectrum than that previously described for any Nepenthes species, with the upper pitchers attracting and trapping a greater quantity and diversity of prey items than the lower pitchers. Capture efficiency was low compared with attraction or retention efficiency. Fragrance of the peristome, or nectar rim, accounted mainly for the observed non-specific, better prey attraction by the upper pitchers, while the retentive properties of the viscous fluid in these upper pitchers arguably explains the species richness of their flying prey. The pitchers of N. rafflesiana are therefore more than simple pitfall traps and the digestive fluid plays an important yet unsuspected role in the ecological success of the species.

【 授权许可】

Unknown