oti po 
takenat the request of the Bureau of Plant Quarantine, which is in- 
terested in the problem because of the possible part played by the 
peach borer in the dissemination of the”phony peach disease and which 
furnished infested nursery stock for the work. The experiments re~ 
sulted in the conclusion that all peach borers may be eliminated from 
nursery stock without Ae to the trees by dipping the stock in hot 
water at 100,5° Fe (425° Ce): for-a period of 1 hours The wargin of 
safety is rather narrow, Gales? since treatment at 13s Fe for 11/2 
hours resulted. in.serious injury, In other experiments it was also 
found that the borers could be eliminated from dug nursery stock with- 
out tree injury by spraying the soil over heeled trees with an emulsion 
containing 15 percent of ethylene dichloride. The direct ap»eication 
of ethylene dichloride emulsion tothe tree roots at streng.ths sufficient 
to kill ell the borers, however, resulted in more or less injurye 
Studies of differences between two species of peach borers.--In. 
making studies of the peach borers, Messrs.Snapp and Thomson have. en- 
countered a problem of distinguishing the larvae of the peach borer 
(Aegeria exitiosa Say) from those of the lesser peach borer (Aegeria 
pictipes Ge & Re), The two species are sometimes found feeding in the 
,same part of the tree, although for the most part the peach borer feeds 
near or below the ground line and the lesser borer feeds in injured 
areas in the higher parts of the tree, In order to obtain authentic 
larval material, borers are being bred from reared adults that may be 
distinguished without difficulty. 
Developmental period of Mexican fruit fly varies in different 
fruits.--W. BE. Stone, of the Mexico Drea ee ‘Mex., laboratory, has found 
that the developmental period of Anastrepha ludens Loew varies with dif- 
ferent host fruits. The following records were made at. a temperature 
of 77° Fe (25° C.): 
Rong t : tots $ Period to first : Period to fimeus 
So Sg SS pees Se A DUP EELS No ae renee ene hier 
: lumber : Days : Days 
Mango---------- : 9 ‘ 1506 $ 4402 
Orange --+------ : 35 ; Chee : 163 
Grapefruit----~: 16 ee vee 259 : wie os 
28) ORO: pelts achat $ 4 : - 404 : “bee 
Although the data are not sufficiently complete to justify con- 
clusions, a possible correlation between the developmental period and re~ 
sistance to vapor-heat sterilization is suggested. In mangoes, in which 
the developmental period is short, the larvae are less readily killed by 
the vaporeheat treatment than in oranges, in which the developmental 
period is tonger. Data are not available. on sterilization of apples» 
‘peters "cockroach: p lant" | contains principle poisonous to fruit 
fliese--C. C. Plummer, 1 Mexico “Oity, has made a study of the interastane 
