
ke 
Bordeaux spray stimulates growth of narcissus bulbs and repels 
lesser bulb fly.--Experiments by F. S. Blanton, Babylon, N. Y., to check 
the value of certain dilutions of a miscible oil with Bordeaux mixture-— 
using a 2 per cent and a 4 per cent oil mixture and straight 4-4-50 Bor- 
deaux--on three varieties of narcissus bulbs have shown that "tL pes ee 
strong dilutions is injurious to the foliage and possibly to the bulbs; 
(2) when the oil has volatilized, it no longer serves as a repellent, 
if it ever did, and with the injured bulb the percentage of flies becomes 
higher; (3) straight 4-4-50 Bordeaux not only keeps the plants in a healthy 
growing condition that reduces the chance of the fly entering the bulb, 
but also, to a certain extent, stimulates and invigorates growth." 
Lethal dosage of hydrocyanic agid gas for bulb insects.--C. F, 
Doucette, Sumner, Wash., reports that "An exposure of one hour, using a 
dosage of sodium cyanide that would provide an average concentration of 
5S mg. of hydrocyanic acid gas per liter of air, gave complete mortality 
definitely and directly exposed to the gas by opening the bulbs just pre- 
vious to fumigation so that the larvae were in the open. An exposure of 
two hours at the same concentration and the same conditions also gave 
complete mortality." This method is differentiated from the fumigation 
of infested bulbs where the flies are in their natural environment. Mr. 
Doucette has also tested this method against species of Eumerus. He 
found that either a one-hour or a two-hour exposure of the larvae to an 
average concentration of 3 mg. of hydrocyanic acid gas per liter of air 
resulted in a 100 per cent kill. Ralph Schcpp, Sumner, conducted similar 
experiments against Liothrips vaneeckei Priessner and reports that "in 
both cases (after one-hour and two-hour exposures) all stages were killed. 
No eggs hatched in the treated bulbs." 
FOREST INSECTS 
Control of bark beetles by tree-injection method.—-In connection 
with control of the bark beetles by the use of chemicals, R. A. St. 
George, Asheville, N. C., reports that preliminary results indicate that 
as small a dosage as one-half gram of sodium arsenite injected into small 
(6 inches diameter-breast-high and 35 feet tall) shortleaf pine trees 
py the saw-kerf method will kill the brood of the southern pine beetle 
(Dendroctonus frontalis Zimm.) in recently attacked trees. For success— 
ful results it is necessary to inject the chemical soon after attack. 
Penetrative oils control early brood of western pine beetle.—-J. 
M. Miller, Berkeley, Calif., reports a series of experiments testing "the 
use of penetrative oils to control the western pine beetle (Dendroctonvs 
brevicomis Lec.) without peeling or burning the bark (of the ponderosa 
pines) * * * Results were found to be highly effective if the oil was 
applied during the early brood stages. Applications during the pupal 
and new-adult stages were less effective, indicating that the oils act 
slowly in reaching the brood and producing mortality." 

