166 EXPERIMENT STATION RECORD. [Vol.40 



" If heliotropin is used without oil it crystallizes out and is soon rubbed off. 

 It is therefore necessary to use some other compound of an oily nature that is 

 too viscous to be absorbed rapidly by the underwear. Experiments with heavy 

 lubricating oils, beeswax, petrolatum, spermaceti, and oil of theobroma (cocoa 

 butter) were conducted. Results showed that a 5 per cent solution of helio- 

 tropin in ether, to which 0.5 gm. of fat or wax was added, would remain 

 effective for 72 hourr.. When increasing the amount of heliotropin it was 

 found to be most soluble in oil of theobroma. When 1 gm. of heliotropin to 

 3 gm. of oil of theobroma dissolved in ether, carbon bisulphid, or benzene was 

 used, spread over 48 sq. in. of underwear, the underwear could be worn for 

 168 hours before it lost its toxicity to lice. 



"Considering the results of all the experiments, it appears that 1GS hours is 

 the maximum time that an effective compound will remain in the underwear in 

 sufficient quantities to kill the lice quickly. Using a less volatile compound, 

 which would remain in the clothing a lonper period of time, would result in a 

 diminished toxicity; that is, an increase in the time required to kill the lice." 



The peach tree borer (Sanninoidea exitiosa), C. (",. BlCKEB (ArJ.iDntnft Sta. 

 Bui. 1.50 (1918), pp. S-32, pis. 2. fig. 1).— This bulletin is based upon investiga- 

 tions begun in 1910, the bioligical studies being made at Fayeiteville and the 

 experiments on control at .\i>i><>tt, Chester, El Dorado. Fayetteville, Rogers, 

 and Van Huron. A paper relating to the biology of the species has been previ- 

 ously noted (E. S. R., 37, p. 15S). The results are summarized by the author as 

 follows : 



"The eggs of the peach . . . borer appear to be 07 per cent fertile. The 

 period of incubation of the egg ranges from 5 days to 2 weeks, th'-ugh it is 

 doubtless longer than this for eggs deposited late in the season. Nearly 85 

 per cent of the larva 1 pupate within a radius of 1 in. from the trunk of the 

 tree. After spinning up, the Insecl may remain in the larval stage within the 

 cocoon for a period of from 5 to days. About 2 weeks are spent within the 

 cocoon as a pupa. The time which elapses from the time that the larva spins 

 its cocoon to the time that the moth emerges ranges from 18 to 80 days. 



"There are four stages in the emergence of the adult from the pupa staire. 

 In the OzarkS, adults may emerge any time from the middle of May until the 

 last of October, but the majority of moths, perhaps 75 to !»> per cent of them, 

 will emerge some time between the middle of August to the middle of Sep- 

 tember. Emergence in the extreme southern part of the State is apparently 

 about one week earlier than it is in northwest Arkansas. 



" Egcrs may be deposited on the trunk, leaves, or twigs of the peach tree or on 

 clumps of dirt or weeds, etc. About 85 per cent of them are deposited at the 

 base of the tree or on the trunk a little higher up. Eight females which were 

 kept in cages without water or food averaged 522 deposited ecrcrs per female. 

 Three females which were fed with sweetened water averaged 722 deposited 

 eu'gs. Females may deposit as many as 1,000 eggs. The average life of a 

 moth appears to be about days. 



" Wrapping papers, tree veneers, white lead paint, asphaltum used on the 

 trunk, lime-sulphur, tanglefoot, Scott's tree protector, tree collars, asphaltum 

 combinations used to seal the crack between the trunk of the tree and the soil, 

 nicotin preparations at different dilutions, carbolineum, carbon disulphid, and 

 heat, all proved to be ineffective or impracticable in controlling the borer. 

 Mounding the trees is attended with danpor when the mounds are leveled so 

 late that the bark does not have a chance to harden properly before cold 

 weather sets in. Removing the soil from the base of the tree and leaving the 

 roots exposed, with a view to freezing the borers, not only fails to kill the 



