Judsonia weekly advance., 1916-11-15

more or less injury locally every year. Like most of our destructive pests, however, it appears as general scourge more or less periodically fol- lowing a series of favorable years. One or more dry summers followed by mild winters usually brings on Hessian fly troubles. The dry weather keeps the pest in the resting condition in the stubb1e and also prevents the blowing under of stubble and then with the early fall rains wheat is sown early on the young wheat. These are the ideal conditions for an outbreak of the fly.
 The injury to wheat is due to the work of the maggot or larval stage of the fly. The small, dark, winged, mos quitolike fly does not attack the wheat. The maggot rasps on the tender plant with a pair of sharp fangs, causing flow of sap which it drinks. The young wheat, when attacked in the fall, stops growing and turns yellow. Usually this first appears where the ground is
 
 1t will finally show up over the whole field. If the weather is favorable til lers are usually produced and the crop is not completely destroyed, unless the infestations be very severe. In the spring the wheat may start off strong and thrifty, but as soon as the rains cease and the spring brood of maggots begins to feed, the wheat stops growing and turns yellow. When the pest is not too abundant the wheat may head out and produce a partial crop, though the heads do not fill prop erly and the grain is light. The lodg- ing or falling of wheat begins about the time of heading and continues un- til it is ripe. In case of severe infesta- tfons no heads form at all.
 Develops Like Other Fies.
 The development of the Hessian fly is similar to that of other flies. The adult winged fly lays eggs on the wheat leaves. These hatch into very small, whitish maggots which feed on the sap of the plant. When nearly full fed the maggot may appear green due to the green sap it contains. When full fed the maggot turns brown and takes on the shape of flaxseed. The maggots in the fixseed stage are of- ten packed together in groups of from six to thirty in the base of wheat plant. Within this brown case the small maggot changes to the resting or pupal stage and later the fly emerges.
 In Kansas and other states of about the same latitude, there Is normally one fall brood, one full spring brood and later partial spring brood of flies. From the last of August to the middle of October the small black mos quitolike flies continue to emerge and lay eggs on the leaves of wheat. Each fly lives but a few days. The females lay an average of 100 eggs. When the eggs hatch the small maggots pass down between the leaf and the small stalk to feed on the stalk. By the time cold weather comes, the maggots are full fed and change to the brown flax seed stage. In this form they spend the winter below ground in the crown of the wheat plant. About the middle of April they hatch and the first brood of Hessian flies appears. These flies lay eggs which hatch during May, pro- ducing the spring brood of maggots In case of warm, damp spring these may mature and produce a second brood of flies Which pass the summer in the wheat stubble in the faxseed stage. It is the brood which is main ly responsible for the destructive fall swarms of flies.
 While this is the normal cycle, some years additional secondary broods may appear and during dry spring the secondary spring brood may not ap- pear at all. Cool, dry weather always retards the development of the fly while warm, damp weather hastens 1t. If there is an excess of moisture dur ing the summer the flies may come from the flaxseed stages in the stub- ble and deposit eggs on volunteer wheat producing secondary summer -brood. In the same way small sec ondary fall brood may appear during November in case of excessive rainfall though such cases are rare. Late sown wheat is seldom attacked except by the spring brood which migrates in from infested fields.
 The Hessian fly Is most effectively controlled by proper methods of farm practice. The destruction of all in- fested stubble very early and the sow ing of wheat late enough in the fall