Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomol00smit Year: 1906 Diseased larva of clover- leaf beetle. quite early in the season, often threatening entire destruction of the crop when they are nearly full grown. Fortunately, nature has provided a check for this insect in a fungous disease which in most localities carries off the larvae annually, just before they mature, leaving only a comparatively small proportion to perpetuate the species. As this disease seems to oc
Economic entomology for the farmer Economic entomology for the farmer and the fruit grower, and for use as a text-book in agricultural schools and colleges; economicentomol00smit Year: 1906 Diseased larva of clover- leaf beetle. quite early in the season, often threatening entire destruction of the crop when they are nearly full grown. Fortunately, nature has provided a check for this insect in a fungous disease which in most localities carries off the larvae annually, just before they mature, leaving only a comparatively small proportion to 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 the 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. Early in the season we find on the leaves and stems of rhubarb a rather long, cylindrical weevil, Li
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