44 



Localities Ixfested. 



This insect is found in Europe, from whence it has probably been brought to this 

 country, but it is not very common there, and is not usually spoken of as a serious clover 

 pest. In America, however, it has become quite formidable. It was first brought to the 

 notice of Prof. Riley in the autumn of 1878, from specimens discovered in Yates County, 

 N.Y., and has proved quite destructive there as well as in several other counties in that 

 State. A correspondent in the American Entomologist, Vol. III., p. 227, writing in 1880, 

 says : It has t-aken all the clover in parts of Genessee County. In half a dozen clover 

 fields examined within a ride of ten miles, every plant pulled up was found to be more or 

 less injured by it." It is during the second year that injury to the clover plant by this 

 insect is most observed. 



Remedies. 



No better remedy is yet known than to plough infested fields in the spring of the 

 third year of the clovei*, at which time the insect is most abundant, and by general agree- 

 ment throughout the more seriously infested districts to refrain from the culture of clover 

 for two or three years. It is not as yet known that any special parasite is attacking this 

 insect, but Mr. Riley on one occasion found the larva of a beetle, a species of Telejyhoriis, 

 preying on it. We have not yet heard of this pest occurring in Ontario, but we cannot 

 expect to be long free from it if it continues to spread among our near neighbours. 



THE CLOYER-STEM BORER— Zaw^wria Mozardi. 



This insect infests the stem of the clover plant, burrowing in it, and either materially 

 weakening it or killing it outright. It occurs throughout the greater portion of the 

 United States, and is also found in Canada. It is, however, a rather rare insect, and one 

 scarcely likely to prove very troublesome, on account of its rarity. It has been bred by 

 Prof. Comstock, of the Department of Agriculture in Washington, who has carefully 

 recorded its habits and changes in the several stages of its existence, and to him we are 

 indebted for the following facts in its history : — 



The eggs are laid in the stems of the clover, in holes gnawed by the parent insect ; 

 they are about one-sixteenth of an inch long (see fig. 16), of a yellomsh colour, rounded 

 at both ends and somewhat curved. They wiU usually be found imbedded in the pith of 

 the stem. The egg is generally laid high up in the stem, and the young, slender, worm- 

 like larvae burrow downwards, consuming the central substance of the stem during their 

 growi:h to the extent of from six to eight inches. The full-grown larva (shown at the 

 ■extreme right in fig. 16) is more than three-tenths of an inch long, of a yellow colour, 

 with six prominent thoracic legs and a prop-leg at the posterior end of the body. The 

 last segment of the body has two stifi" spines above, slightly curved upwards. 



The larva changes to a chrysalis (see fig. 16) in the lower part of its burrow. The 

 time of the pupal state varies much in its duration ; the beetles begin to issue in August, 

 and continue to emerge until late in October. There is probably but one brood of the 

 insect in a season, the insect hibernating for the winter in the beetle state. 



The beetle (fig. 16) is slender and cylin- 

 drical, with a yellowish-red thorax. The 

 wing-covers are bluish-black with a green 

 tinge, and are marked with deeply-impressed 

 punctures arranged in regular roAvs. In fig. 

 16 the insect is represented in its various 

 stages, together with the work of the larva 

 within the stem. Prof. Comstock has found 

 two species of parasites within the burrows 

 of the stalk-borers — the one a small, black 

 chalcid fly, the dark, naked pupa of which 

 jj. was often met with ; and the other a yellowish 

 ichneumon, the pupa of which was enclosed 

 in a delicate white silken cocoon. Possibly 



Fig. 16. 



