. Circular. Insects. 10 joints, thus leaving the larvae, if there are such in the straws at that point, exposed to attack from predaceous insects. The larvae of a small, slender, black and yellow carabid beetle (Leptotrachelus dor- salis Fab.) crawls up the stalks, descends into the stubble, and devours the Isosoma larvae, but unfortunately its taste is such that it does not confine itself strictly to Isosoma but devours parasite as well as host. The mite Pediculoides (Heteropus) ventricosus (fig. 13) is also an enemy, gaining access to the larvae precisely as do the beetle larvae previously m
. Circular. Insects. 10 joints, thus leaving the larvae, if there are such in the straws at that point, exposed to attack from predaceous insects. The larvae of a small, slender, black and yellow carabid beetle (Leptotrachelus dor- salis Fab.) crawls up the stalks, descends into the stubble, and devours the Isosoma larvae, but unfortunately its taste is such that it does not confine itself strictly to Isosoma but devours parasite as well as host. The mite Pediculoides (Heteropus) ventricosus (fig. 13) is also an enemy, gaining access to the larvae precisely as do the beetle larvae previously mentioned. PREVENTIVE MEASURES. There are no remedial measures, since it is impossible to alleviate or influence in any way the effect of larvse in the infested wheat plants. As it is the larger and more vigorous plants that the females select for egg-laying purposes, no amount of enriching the soil will affect the numbers of the pest or lessen their influence. Preventive measures are, however, sim- ple, practicable, and effective. Indeed, the wheat- straw worm is one of the very easiest of all insects to control. The diminutive size of the female that emerges in early spring renders extended migrations fatal, since during that period, when the weather is, of all seasons, the most erratic and liable to sudden and extreme changes, it tries to avoid the frequent storms by seeking protection on the underside of the leaves of the growing plants. But, most fortunate of all for. the farmer, large numbers, if not indeed much the greater proportion, of these females have no wings and can only make their way from place to place by crawling. The advantage of all of this to the farmer is shown by the fact that, where the preceding crop has been other than wheat, the injury to the young wheat plants in spring is confined to the margins, and especially where such margins border on other fields that have .been devoted to wheat for a number of consecutive years. Mr. Reeves, as will be ob- serv
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Keywords: ., bookcentury1800, bookdecade1890, bookpublishe, booksubjectinsects
