-98- 
DDT was applied aa dusts (3 and 5 percent) and as a spray (4 pounds 
of a wettable powder containing 25 percent of BDT per 100 gallons) on 
grapes. Fewer specimens were found on the treated plants than on un- 
treated plants but no dead beetles were found beneath or near the treat- 
ed plants. Smaller leaf areas were consumed on the plants treated with 
DDT than with any of the other materials tested.- Polivka ( 294 ) . 
Scolytidae 
Dendroctonus engelmarmi Hopk., the Engelmann spruoe beetle 
Preliminary results indicate that these beetles were prevented from 
attacking green logs in the laboratory by the application of DDT in an 
oil emulsion, and finally all wero killed.— Craighead and Brown (125 ) . 
Scolytus multistriatus (Marsham) , 1he smaller European elm bark beetle 
In extensive experiments conducted at korristown, N. J., solutions 
and emulsions containing 2 to 5 percent of DDT prevented crotch feeding 
in living elm trees by adult beetles for more than 110 days. Lower 
concentrations of DDT were effective for shorter periods. Similar sprays 
containing as little as 0.25 percent of DET prevented beetles from enter- 
ing the bark of sprayed logs for over 69 days, and sprays containing 2 
percent of DDT gave protection for more than 160 days. An emulsion con- 
taining 0.5 percent of "DOT, when applied to elm wood infested with larval 
broods, permitted some emergence of adults, but affected tne emerging 
beetles to the extent that none were able to attack suitable material 
caged with them. Solutions of as little as 0.25 percent of DDT, when 
applied to similar infested material, prevented all em erg enoe.— Craighead 
and Brown (125 ) • 
Scolytus rugulosu8 (Ratz.), the shot-hole borer 
In California three almond trees were treated with a DDT spray but 
the effect on the borers was not determined. —Swans on and Michelbacher 
(340). 
Ambrosia beetles 
Bark beetles 
See under Cerambycidae .— Craighead and Brown (125 ) • 
Tenebrionidae 
Blapstinus auripilis Horn, a darkling beetle 
In a cage test 100 percent kill of this insect was obtained in 67 
hours with 2 percent DDT. — Loftin (247). 
