12 MISCELLANEOUS RESULTS OF WORK OF BUREAU TX. 



the conditions in western Texas, such as those obtaiijing; at Barstow, 

 probabl}^ little good could be accom])lished by such measures. With 

 the niesquite-covered surrounding districts as a stronghold these 

 insects probably will become established in the alfalfa fields each year 

 and become more or less numerous as the season j^rogresses, their 

 numbers being governed by conditions which for the most part exert 

 their influence secondarily through the natural enemies of the species. 

 The question of control at Barstow. and where similar conditions 

 prevail, resolves itself into : First, avoidance of damage to the seed 

 croj) of alfalfa ; second, methods tending to j^revent the insect's 

 spread from alfalfa to other crops, or otherwise preventing infesta- 

 tions; third, direct remedies applicable for use wdien crops other than 

 alfalfa become infested. 



AVOIDANCE OF INJURY TO THE SEED CROP OF ALFALFA. 



At Barstow the exi^erience of alfalfa growers for two successive 

 seasons, supported by direct observation by Mr. Crawford and the 

 writer at regular intervals during 1905, has shoAvn that the conchue- 

 las are so numerous during July and August that an attempt to pro- 

 duce a seed crop during this period would be inadvisable. In north- 

 ern Mexico observations extending over three seasons have shown the 

 insects both to reach a maximum in numbers and to show a marked 

 decrease therefrom during the last two weeks of July. This cor- 

 responded with the history of the pest at Barstow, and it is believed 

 that the danger limits above given are sufficiently wide to cover* all 

 but exceptional cases under the present conditions. If a crop 

 intended for seed promised to mature before July.l, probably but 

 little damage would be accomplished by the conchuela, but this is 

 entirely a surmise which it is hoped will be thoroughly tested when 

 an opportunity presents itself. The same probabilities hold for a crop 

 of seed which would mature after the 1st of September. This, more- 

 over, has been substantiated by the experience of Miller Brothers at 

 Barstow, which has been descril;)ed under the subject of damage to 

 alfalfa in 1905. Avoidance of the injury as here outlined is undoubt- 

 edly simpler than actually defending the seed in the field from attack. 



A SUGGESTION AS TO MECHANICAL CONTRI^•ANCES FOR COLLECTING THE 



INSECTS. 



Between the conchuela {P. ligata) and its near relative, the grain 

 bug {P. suyl), whose reputation as a i^est has already been men- 

 tioned, it may be anticipated here that in the course of time remedies 

 will be demanded for use against such insect enemies of alfalfa in 

 other sections of the country. In a field with ripening seed an ex- 

 periment with an insect-collecting net in one hand and a stick in the 

 other, simulating the action of an imaginary specially constructed 



