. 17 .
.   3
treatment of all old patches early in the spring, followed by treatments of new patches,
at least on the borders closest to an old patch or other sources of infestation such as
° cinquefoil (five -finger). Treatment of new patches would require the use of very little l
material, since only a puff of dust is needed per plant.
Table}
1949 Laboratory Tests of Organic Insecticides for Control of Strawberry Crown
Borer Adults. (Counts made 3 to 5 days after treatments.)
’ ____;’;=;;=;&.P;e¢l__*._.__
I Treatment April 9 April 14 April 27
2% Parathion ——--—~— 100 100 None used
l l/2% gamma BHC
(odorless) ————— 65.5 10.3 None used
20% Toxaphene ····· 96.9 100 None used
5% Chlordane --——— 100 100 None used
Check
No Treatment -————— 2.6 0 4.3 1
, DDT 1 lb. Actual
_ per 100 gallons - - ·— - — None used 65.8 None used
5% DDT · —·——- ·· — — -· None used 32.4 None used
1% Parathion ——-——- None used None used 100
2 1/2% Compound 118 — None used None used . 76.3
Q 3% gamma BHC
R, (odorless) — — ·— — — None used None used 30.6
§u1Infn_a_ry. One and 2 percent Parathion dust, 5 percent Chlordane dust, and 20
percent Toxaphene dust all gave excellent control of strawberry crown borer adults
in laboratory tests. Five percent Chlordane and 20 percent Toxaphene were tried in
the field and gave similar results. Early spring treatment of old strawberry patches
and repeated treatment of borderrrovvs in newly set patches are suggested as means of
controlling crown borer by killing adults before egg-laying occurs.