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). 



