356 EXPERIMENT STATION RECORD. [VoL 41 



" The cultivation of large areas formeny devoted to grazing eliminated 

 tlie native food plants of tlie insect and causetl it to attack cultivated 

 plants. This change to more succulent food plants, together with the superior 

 facilities afforded for hibernation in the cultivated areas, resulted in an 

 increase of the pest beyond its former abundance. "Wheat, barley, and rye 

 are the preferred food plants among the cultivated crops. The species also 

 feeds upon other cereals, and upon alfalfa, cotton, peas, beans, cabbage, 

 tomato, and lettuce, in addition to many native plants. The first recorded 

 damage occurred in 1903, and since that time destructive outbreaks have 

 been reported from most of the States west of the Great Plains area. 

 Weather influences and the work of the parasites generally restrict destructive 

 outbreaks in each locality to periodic intervals of two or three years. 



"Adults emerge from hibernation in the early spring and deposit eggs on 

 the material composing the hibernating quarters. The resulting nymphs 

 feed upon tender plants growing in the vicinity. Upon reaching maturity the 

 adults migrate to grain fields and feed upon the developing heads. There are 

 three distinct generations and sometimes a partial fourth, generation annually. 

 About 50 days are required to complete the life cycle of eacli generation. 



"After midsummer the numbers of the insects are greatly reduced by an egg 

 parasite, Telenomus ashmeadi, and by two species of tachinid parasites, Gynv- 

 nosoma fitliginosa and Ocypterodes eucJicnor, which parasitize the adults. Sev- 

 eral kinds of predacious enemies contribute to the same result. 



" Hibernation occurs in the adult stage under weeds or rubbish. No nymphs 

 or eggs survive the winter. Severe winters result in the death of a large per- 

 centage of hibernating adults and constitute one of the most important factors 

 in restricting destructive outbreaks of the species. During normal winters at 

 least 95 per cent of the adults survive when hibernating in protected locations. 



" The most effective and practical method of control is the destruction of the 

 adults while they are concentrated in their winter quarters. This is best accon>- 

 plished by plowing under, or burning, all rubbisti and weeds, particularly Rus- 

 sian thistle, in and about cultivated fields. These control measures should be 

 included as a part of the regular farm practice, and any special work required 

 may be carried on during the inactive season at a time when the farm labor and 

 equipment ordinarily are idle. Trap crops, hand picking, and hopperdozers 

 might prove practical in the control of the insect Tinder special conditions." 



Five new^ species of Jassoidea from Honduras (Hemiptera: Homoptera), 

 E. H. Gibson (Proc. Biol. Soc. Wasli., 32 {1919), pp. 25-28). 



Combining dormant and first summer spray in apple orchards infested by 

 San Jose scale, T. J. Talbert (Missotiri Sta. Bui. 161 {1919), pp. 3-15, flffs. 3).— 

 This is a report of experiments and observations, extending over a period of 

 four years, which have shown that the dormant or San Jose scale spray con- 

 sisting of commercial lime-sulphur testing 33° B. may be applied to apple trees 

 at a dilution of 1:7 or 1:8 after growth starts and until the trees begin to 

 bloom without material injury to leaves or flower buds. When applied after the 

 leaves are out and the buds are beginning to show their petals, it takes the place 

 of the so-called cluster-bud or first sununer spray, thus eliminating the cost of 

 labor and materials for one summer application. 



" Commercial lime-sulphur when used at a dilution of 1 : 7 produces more 

 burning than when used at a dilution of 1 : 8, 1 : 10, or 1 : 12. As a rule, the 

 weaker the solution the less the burning. The difference in the caustic or burn- 

 ing effect, however, has been very slight, especially between the dilution of 1 : 7 

 and 1:8. A spraying pressure of from 250 to 300 lbs. is much more apt to cause 

 injury by burning than a pressure of 200 lbs. or less." 



