Jackson Robert R, Deng Chan, Cross Fiona R
School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand; International Centre of Insect Physiology and Ecology, Thomas Odhiambo Campus, PO Box 30, Mbita Point, Kenya.
R Soc Open Sci. 2016 Dec 7;3(12):160584. doi: 10.1098/rsos.160584. eCollection 2016 Dec.
On the basis of 1115 records of feeding in the field, we can characterize this East African jumping spider (Salticidae) as being distinctively stenophagic. We can also, on the basis of laboratory prey-choice experiments, characterize . as having a specialized prey-classification system and a hierarchy of innate preferences for various categories of mosquitoes and other arthropods. Prey from the field belonged to 10 arthropod orders, but 94.5% of the prey records were dipterans. Mosquitoes were the dominant prey (80.2% of the records), with the majority (82.9%) of the mosquitoes being females, and thereafter midges were the most common prey (9.2% of the records). Preference profiles that were determined from experiments showed strong convergence with natural diet in some, but not all, instances. In experiments, . adults appeared to distinguish between six prey categories and juveniles between seven, with blood-carrying anopheline female mosquitoes being ranked highest in preference. For adults, this was followed by blood-carrying culicine female mosquitoes and then anopheline female mosquitoes not carrying blood, but these two preferences were reversed for juveniles. Moreover, for juveniles, but not for adults, anopheline male mosquitoes seem to be a distinct prey category ranked in preference after blood-carrying culicine females and, for both adults and juveniles, preference for midges is evident when the alternatives are not mosquitoes. These findings illustrate the importance of going beyond simply specifying preferred prey categories when characterizing predators as 'specialized' and a need to make clear conceptual distinctions between a predator's natural diet, the prey categories that are relevant to the predator, and the predator's prey-choicebehaviour.
基于1115条野外捕食记录，我们可以将这种东非跳蛛（跳蛛科）的食性特征描述为明显的狭食性。同样，基于实验室猎物选择实验，我们还可以将其描述为具有专门的猎物分类系统以及对各类蚊子和其他节肢动物的先天偏好等级。野外捕获的猎物属于10个节肢动物目，但94.5%的猎物记录是双翅目昆虫。蚊子是主要猎物（占记录的80.2%），其中大多数（82.9%）是雌蚊，其次是蠓是最常见的猎物（占记录的9.2%）。实验确定的偏好概况在某些但并非所有情况下都与自然饮食有很强的趋同性。在实验中，成年个体似乎能区分六种猎物类别，幼年个体能区分七种，携带血液的雌性按蚊在偏好等级中排名最高。对成年个体来说，其次是携带血液的库蚊雌蚊，然后是不携带血液的按蚊雌蚊，但这两种偏好对幼年个体来说是相反的。此外，对于幼年个体而非成年个体，按蚊雄蚊似乎是一个独特的猎物类别，其偏好等级排在携带血液的库蚊雌蚊之后，而且对于成年个体和幼年个体来说，当没有蚊子可供选择时，对蠓的偏好都很明显。这些发现表明，在将捕食者描述为“特化”时，仅仅明确偏好的猎物类别是不够的，还需要在捕食者的自然饮食、与捕食者相关的猎物类别以及捕食者的猎物选择行为之间做出清晰的概念区分。
