. Agricultural zoology. Zoology. INSECTS. 109 beetles with thick-set bodies. In a state of rest the proboscis is folded back into a ventral furrow, situated between the fore-hips. They are black, and thickly- covered with grey hairs. Live on cruciferous plants. The Turnip Gall Weevil {Geutorhynchus sulcioollis), one-eighth of an inch long, dull black, with many grey hairs on the ventral side and few on the dorsal side. The deeply pitted neck-shield has in its centre a well-marked longi- tudinal furrow. Wing - covers deeply furrowed. The beetle ap- pears in April, and gnaws the flowers and shoo
. Agricultural zoology. Zoology. INSECTS. 109 beetles with thick-set bodies. In a state of rest the proboscis is folded back into a ventral furrow, situated between the fore-hips. They are black, and thickly- covered with grey hairs. Live on cruciferous plants. The Turnip Gall Weevil {Geutorhynchus sulcioollis), one-eighth of an inch long, dull black, with many grey hairs on the ventral side and few on the dorsal side. The deeply pitted neck-shield has in its centre a well-marked longi- tudinal furrow. Wing - covers deeply furrowed. The beetle ap- pears in April, and gnaws the flowers and shoots, but can scarcely be considered as harmful. In late summer or autumn, after the sprouting of the winter rape, the female bites into the root immediately under the surface of the soil, or into the lower parts of the stem, so as to form a hole in which she lays one or two eggs. As the larva begins to develop, the surrounding parts of the stem or root grow into a gall- like sweUing (Fig. 80). At the beginning of spring the developed larvae creep out, and become pupse in the soil; in April the beetle appears. If the Ceutorhynchus galls are only present in small numbers they damage the rape plants only to a small extent, but when ten to twelve are found in one plant the roots grow crooked, and remain short, and consequently the growth of the overground parts is detrimentally affected. Ceutorhynchus galls are. Fig. 80.—Turnip Gall Wee- vil (^Ceutorhynchus suld- coUis).. 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 Bos, Jan Ritzema, 1850-1928; Ainsworth Davis, J. R. (James Richard), 1861-1934. London, Chapman & Hall, Ld.
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1894
