562 EXPERIMEKT STATION RECORD. 



In all the observations made it was found that the covering leaf-sheath was 

 pierced and the eggs deposited in the joints. In 1909 the joints high up in the 

 straw were attacked, while in 1910 the lower ones were selected. It appears 

 that the youngest joints are selected by instinct in order to allow the longest 

 possible time for the development of the larva before the hardening of the straw. 

 The author is of the opinion that the higher up the stalk is injured the less is 

 the resulting damage that may be expected. While the larvae sometimes occur 

 singly, at other times as many as 25 will be found above a single joint, each in a 

 single cell. Hibernation occurs in the closed larval cells, the insect being 

 either in the larval or pupal stage. This affords an excellent opportunity for 

 remedial measures. It is shown that moisture in the straw which contains the 

 hibernating insects has much to do with the future of the pest. Adults forced 

 to emerge by keeping stubble in a warm room were exposed for 19 hours on 

 December 22 to a temperature that dropped to 10° F., without ill effect. Maps 

 are given which indicate the localities in Ohio in which it was definitely ascer- 

 tained that this pest occurred during the years 1908, 1909, and 1910. 



Observations were made of the varieties of wheat affected. " Taken as a 

 whole, the study of varieties, as pertains to the jointworm problem, indicates 

 that one should select a wheat with a fair-sized, stiff straw, which is known to 

 do well in his section. The stiffness prevents falling, and if the straw is fair- 

 sized, it is believed that the presence of the jointworm larvje within its walls 

 does not injure it to the extent that it would if the straw were undersized." 



Tests of the effect of fertilizers are reported in tabular form. A study made 

 of the 3 tests described reveals no evidence as to whether or not fertilized or 

 unfertilized wheat is more susceptible to jointworm attack under all condi- 

 tions and during various seasons. The author concludes, however, that it pays 

 to fertilize liberally as the increased yield more than offsets the harm pro- 

 duced by the greater percentage of infestation which may prevail. 



As regards the time of seeding the author states that at present the only 

 dependable recommendation to be made is that the wheat be sown on that date 

 which with average conditions has been found to yield the best crop. He 

 thinks that the danger from straw stacks has been imduly emphasized and that 

 the danger from old stubble has been too little considered. His observations 

 indicate that wheat adjoining stubble is more severely infested than that grown 

 some distance away. It was found, however, that the jointworm adults will 

 fly at least a quarter of a mile, and it is probable that under stress they will 

 fly much farther. Of the several species of parasites Ditropinotus aureoviridis 

 occurs in greatest numbers. The fungus Sporotrichum globulifenim was found 

 during 1909 and 1910 to have destroyed great numbers of over-wintering pupae. 



The burning of the stubble of the year previous is considered by all odds the 

 easiest and most effective measure to be used against the wheat jointworm, 

 the other remedies to be employed being " nothing more than a thorough system 

 of progressive farm practice." 



The cotton red spider, E. L. Worsham (Georgia Sta. Bui. 92, pp. 135-1/fl, 

 pis. 5). — The author finds that in the latitude of Atlanta the red spider 

 (Tetranychus gloveri) passes the winter in the adult stage and even propagates 

 sparingly at a temperature slightly above freezing. 



" Repeated examinations of a cotton field at Unadilla revealed the spider 

 present throughout the winter on green vegetation in the field, on a ditch 

 bank, and in a marsh adjoining the field. Some few blackberry leaves re- 

 mained green all winter and furnished food for great numbers of adult spiders. 

 The common goldenrod was another important winter food plant. In fact, 

 all green vegetation about the field, with the exception of tough-leafed plants, 

 such as bramble brier, were found to house small colonies of spiders. The 



