418 



owing to the fact that on a tall and narrow tree more of the tent area 

 is disposed in folds near the ground, and these may be loose enough 

 to allow the gas to diffuse between them, resulting in a reduction of 

 kiUing efficiency of 26'9 per cent. In the case of the low and broad 

 tent there was a difference of 18 "9 per cent, between the top and bottom 

 of the tent, and between the two tents a difference of efficiency, in 

 favour of the low tent, of 194 per cent. 



The unsatisfactory results obtained with insects on low and broad 

 trees, together with complaints of injury to the tops of tall trees, owing 

 to the accumulation of the gas which is lighter than air, are due to 

 faulty dosage tables based on the circumference and distance over 

 the top of the trees, data which give neither the true cubic content 

 nor the internal area of the tents when in position. 



Severin (H. H. p.) & Thomas (W. W.). Notes on the Beet Leaf- 

 hopper, Eutettix tenella, Baker. — Ji. Econ. Entom., Concord. N.H., 

 xi, no. 3, June 1918, pp. 308-312. 



An investigation was undertaken to determine the hibernating 

 sites of Eutettix tenella (beet leaf-hopper) and to locate its breeding- 

 places in the State of California, since the view has been held that 

 it breeds in arid or desert regions and that the migration of enormous 

 numbers of this pest have caused three serious and widespread out- 

 breaks of curly-leaf of beet in California and one in Utah in 1915, 

 from flights from the California outbreaks in 1914. 



As a result it was found that the insect breeds on Atriplex semi- 

 baccata (Australian salt bush) in January and March, and on 

 Sesuvium sessile (lowland or sea purslane) in March in the cultivated 

 districts of the Imperial Valley, though no complete hibernation 

 occurs there. 



The names are also given of a large number of wild plants on which 

 after careful examination it was not found to occur. 



DoANE (R. W.). Some Problems in the Control of Insects in Stored 

 Foods in California. — Jl. Econ. Entom., Concord, N.H., xi, no. 3, 

 June 1918, pp. 313-320. 



The most important insect pests attacking stored food in California 

 are : — The Mediterranean flour moth [Ephestia kuhniella], the larvae 

 of which mat together the flour in bins and sacks with masses of 

 webbing, and puncture the sacks on emerging to seek suitable 

 places for pupation' ; Calandra oryzfie, L. (rice weevil) ; C. granaria, 

 L. (granary weevil), which usually occurs only in small numbers ; 

 Silvanus sarinamensis (saw-toothed grain beetle), commonl}- associated 

 with the preceding and sometimes very abundant and destructive ; 

 Tribolium confusum (confused flour beetle), a general feeder, attacking 

 nearly all kinds of food products ; T. navnle, F., the presence of which 

 imparts a disagreeable musty odour to food, bread baked from 

 infested flour having a disagreeable odour, which however disappears 

 as it cools ; other unidentified moths and beetles, and a mite, probably 

 Tyroglyphus longior, Ger. 



Preventive measures consist, primarily, of cleanhness and a careful 

 watch on all incoming material, The former is attained in many 



