Wright Mark G, Samways Michael J
Agricultural Research Council, Roodeplaat Vegetable and Ornamental Plant Institute, Private Bag X1, Elsenburg 7607, South Africa, , , , , , ZA.
Invertebrate Conservation Research Centre, Department of Zoology and Entomology, University of Natal, Private Bag X01, Scottsville 3209, South Africa Fax: +27 21 8085440; e-mail:
Oecologia. 1998 Jul;115(3):427-433. doi: 10.1007/s004420050537.
The Cape Floristic Region (CFR) is one of the most plant-species-rich regions in the world. It is also a warm temperate region and hypothetically should have high gall-insect species richness, making it interesting to investigate the relationship between the insects of the region and the rich flora. The relationship between gall-insect species richness (GSR) and plant richness was investigated for the Fynbos and for representatives of vegetation of the whole CFR. Samples (of up to 600 plants per transect for Fynbos) of woody shrubs were investigated for the presence of galls. The species richness of these insects was quantified, as well as plant species richness for each transect. GSR for Fynbos was compared to global figures for GSR. Fynbos harboured significantly more gall-insect species than other CFR vegetation types. GSR was positively correlated with CFR plant richness. GSR also closely tracked plant richness in Fynbos. GSR was not significantly influenced by other variables (elevation and aspect), suggesting that plant richness per se was an important factor in generating GSR. Fynbos GSR is comparable to other sclerophyllous regions of high GSR globally, corroborating that this vegetation type is conducive to gall-insect diversification. There is likely to be a high percentage of gall-insect endemism in the Fynbos, as might be expected from the high host fidelity of this insect group.
开普植物区（CFR）是世界上植物物种最为丰富的地区之一。它也是一个暖温带地区，据推测应该有丰富的瘿蚊物种，因此研究该地区昆虫与丰富植物群之间的关系很有意思。我们研究了细叶石南灌丛以及整个开普植物区植被代表的瘿蚊物种丰富度（GSR）与植物丰富度之间的关系。对木本灌木样本（细叶石南灌丛每个样带最多600株植物）进行了瘿瘤调查。对这些昆虫的物种丰富度以及每个样带的植物物种丰富度进行了量化。将细叶石南灌丛的GSR与全球GSR数据进行了比较。细叶石南灌丛中的瘿蚊物种比开普植物区的其他植被类型要多得多。GSR与开普植物区的植物丰富度呈正相关。在细叶石南灌丛中，GSR也与植物丰富度密切相关。GSR不受其他变量（海拔和坡向）的显著影响，这表明植物丰富度本身是影响GSR的一个重要因素。细叶石南灌丛的GSR与全球其他高GSR的硬叶植物区相当，这证实了这种植被类型有利于瘿蚊的多样化。正如从该昆虫群体的高寄主专一性所预期的那样，细叶石南灌丛中很可能有很高比例的瘿蚊特有种。
