Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomolo00smit Year: 1906 23° A A' ECONOMIC ENTOMOLOGY. ' IG. 235. Diseased larva of clover- leaf beetle. quite early in the season, often threatening entire destruction ol' the cro[) when they are nearly full ^rown. P'ortunately, nature has proxiflefl a check for this insect in a funj^ous disease which in most localities carries off the larvcp annually, just before they mature, leaving only a comparatively small proportion lu perpetuate the species. As this d
Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; . economicentomolo00smit Year: 1906 23° A A' ECONOMIC ENTOMOLOGY. ' IG. 235. Diseased larva of clover- leaf beetle. quite early in the season, often threatening entire destruction ol' the cro[) when they are nearly full ^rown. P'ortunately, nature has proxiflefl a check for this insect in a funj^ous disease which in most localities carries off the larvcp annually, just before they mature, leaving only a comparatively small proportion lu perpetuate the species. As this disease seems to occur in seasons of all kinds, and irrespective of climatic conditions, it can be easily introduced into any locality in which the insects become destructive. Affected larvae curl themselves round a spear of grass or on the edge of a leaf and die, first swelling somewhat and becoming gray in color ; then they collapse and become black, eventually forming a small, dried, black mass, utterly indistinguishable in character. The ' white-pine weevil,' Pissodes strobi, is one of the most serious enemies to that tree, and in the more northern States attacks the leading shoots, in young trees spoiling their shape completely. The insect has been studied, and a full account is given in the Fifth Report of f'iG. 236. ^\^Q United States Entomological Commission, dealing with forest insects, but no satisfactory reme- dial measures are proposed. In parks or gardens small orna- mental trees can probably be protected by keeping the leading shoots sprayed during the spring with a carbolated soap-wash, to which Paris green has been added at the rate of one pound in one hundred and fifty gallons of water. Other infested shoots should be gathered and burnt. The report above cited is so full on the subject of forest insects belonging to this series that only those infesting cultivated crops need be discussed here. Earlv in the season we find on the leaves and stems of rhubarb a rat
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