. A text-book of agricultural zoology. Zoology, Economic. 168 HYMENOPTEEA (SAWFLIBS). single egg only is placed on the under-side of each leaf, its position being easily told by the small pale-brown spot on the leaf that appears over it. The ovum hatches in two weeks, and the larva escapes to the top of the leaf. At first it is white and free from slime; but soon a slimy exudate comes out of its skin and gives it its typical slug-like appearance. The form is peculiar, being much swollen up at the head-end: twenty legs are present in all. In four weeks the slug-worm has reached maturity, when i
. A text-book of agricultural zoology. Zoology, Economic. 168 HYMENOPTEEA (SAWFLIBS). single egg only is placed on the under-side of each leaf, its position being easily told by the small pale-brown spot on the leaf that appears over it. The ovum hatches in two weeks, and the larva escapes to the top of the leaf. At first it is white and free from slime; but soon a slimy exudate comes out of its skin and gives it its typical slug-like appearance. The form is peculiar, being much swollen up at the head-end: twenty legs are present in all. In four weeks the slug-worm has reached maturity, when it attains the length of half an inch. At the last moult (the fifth) it loses its slimy character, and becomes dry and dirty-yellow in colour. It then passes down to the ground, where it forms a cell and pupates. In the summer broods, of which there are three in England, the pupal life lasts about fourteen days. It seems that they do not all undergo these stages at the same time, some remaining in the ground much longer than others. liTumbers of larvse are often found on one leaf of different sizes, the eggs having been deposited by different insects at various times. Prevention and Remedies. — Similar preventives apply here. Fio. 74.—Leaf op Cherry eaten by Sluq-wohms. as in the Gooseberry Sawfly. Lime will soon kill the larvse if it is applied twice in succession, as they have the power, like. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Theobald, Frederick Vincent, 1868-1930. Edinburgh and London, W. Blackwood and sons
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1899
