This section is from the book "Commercial Gardening Vol1", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
The true spiders, being perfectly harmless to plants, and living upon various kinds of insects, should never be destroyed by gardeners, although their webs and nests often present a very untidy appearance if allowed to remain in potting sheds, greenhouses, lofts, etc. The common garden spider, known as Epeira diadeimata, is a pretty, greyish insect beautifully speckled or spotted with white on the back of its roundish abdomen. It lives upon moths and flies of various kinds, and will easily defeat a vicious wasp in a straight fight by winding its silken cords around it.
A kind of leaping spider (Epiblemum scenicum), shown in fig. 163, leaps about amongst plants, and pounces upon its prey. It is grey in colour with oblique white bands on the back of the abdomen and legs.