Erlandsson Ann
Department of Animal Ecology, Lund University, Ecology Building, S-22362, Lund, Sweden.
Oecologia. 1992 May;90(2):153-157. doi: 10.1007/BF00317171.
Interspecific interactions were studied in three coexisting species of predatory semiaquatic insects: Gyrinus substriatus Steph. (Coleoptera), Gerris lacustris (L.) and Gerris argentatus Schumm. (Hemiptera). Prey capture success was observed in trials with individuals of two different species. Two prey sizes were used: fruit flies Drosophila melanogaster and Mediterranean flour moths Ephetia kuehniella (Zeller). When the two species were starved for the same period of time, G. substriatus was generally more successful at catching prey than either Gerris species, independent of prey size. However, when individuals from the formerly dominant species of the pair were less hungry (i.e. fed shortly before trials), their prey capture success decreased. Prey sharing and prey stealing were observed in trials with large prey and occurred both intra- and interspecifically. The shift in dominance with differing hunger levels and the existence of prey sharing and prey stealing may make the interspecific competition more symmetric allowing these species to coexist.
条纹龙虱（Gyrinus substriatus Steph.，鞘翅目）、普通黾蝽（Gerris lacustris (L.)）和银斑黾蝽（Gerris argentatus Schumm.，半翅目）。在涉及两个不同物种个体的试验中观察了猎物捕获成功率。使用了两种猎物大小：果蝇（Drosophila melanogaster）和地中海粉螟（Ephestia kuehniella (Zeller)）。当两个物种饥饿相同时间时，无论猎物大小如何，条纹龙虱通常比任何一种黾蝽更成功地捕获猎物。然而，当配对中先前占优势物种的个体不太饥饿时（即在试验前不久喂食），它们的猎物捕获成功率会降低。在使用大型猎物的试验中观察到了猎物共享和猎物窃取现象，种内和种间均有发生。不同饥饿水平下优势地位的转变以及猎物共享和猎物窃取的存在可能会使种间竞争更加对称，从而使这些物种得以共存。
