Contribution of pitcher fragrance and fluid viscosity to high prey diversity in a Nepenthes carnivorous plant from Borneo
Contribution of pitcher fragrance and fluid viscosity to high prey diversity in a Nepenthes carnivorous plant from Borneo
复制标题
DOI：
10.1007/s12038-008-0028-5
复制
发表时间：
2008-03-01
影响因子：
2.9
通讯作者：
Gaume, Laurence
中科院分区：
文献类型：
--
作者：
Di Giusto, Bruno;Grosbois, Vladimir;Gaume, Laurence
提高食肉植物猎物丰富度的机制可能涉及诱捕的三个关键阶段：吸引、捕获和保留。猪笼草是一种食虫猪笼草，广泛分布于婆罗洲北部。它表现出个体发生的投手二态性，上面的投手比下面的投手捕获更多的飞行猎物。虽然这种猎物组成的差异被归因于吸引力的差异，但捕获和保留的贡献被忽视了。本研究的重点是区分猎物捕获机制，并评估它们对猎物多样性的相对贡献。分析了两种投食器中访食者和猎物节肢动物的丰富度和多样性，量化了吸引力对捕获猎物的相对贡献。记录了昆虫对不同水罐部位的访问率以及有无甜味的记录，以阐明吸引的起源和机制。通过昆虫生物测定和液体粘度测定，研究了其滞留机理。研究发现，rafflesiana鼠笼草捕获的猎物范围比以前描述的任何一种鼠笼草都要广，上面的鼠笼草比下面的鼠笼草吸引和捕获的猎物数量和多样性都要大。与吸引和滞留效率相比，捕获效率较低。花蜜边缘的香味主要解释了观察到的非特异性、更好的猎物被上层壶状体吸引的原因，而这些上层壶状体中粘性流体的保留特性可能解释了它们飞行猎物的物种丰富性。因此，N. rafflesiana的壶状体不仅仅是简单的陷阱，消化液在物种的生态成功中起着重要而不可思议的作用。
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.