Bulletin 151, Truck and Garden Insects


out without getting wet by it. Pass down the rows rather
slowly and let the spray play for a second or two on each cluster
or "hand." This not only insures a thoro drenching but also
gives the insects time to crawl out to where the spray can hit
them. Use as much pressure as possible, for the double pur-
pose of driving the liquid into the blossoms and of frightening
the insects out by the force of the spray against the flowers.
 Different tobacco decoctions, of which there are many on
the market, vary much in the strength of nicotine present, and
consequently, in the proportions in which they should be mixed
with water. Black leaf 40 should be used in about the pro-
portion of 1 part to from 1000 to 1800 of water. The weaker
solutions (as black leaf 2 1/3 percent) in about 1 to 100; while
1 part of home-made tobacco extract should be used with about
10 of water.
 It is advantageous to put into the solution something to
give it better sticking qualities. The writer used the following
mixture on tomatoes during April, 1912, and killed about three-
fourths of the thrips present. This solution was previously
found very effective against the orange thrips in California:
 Commercial lime-sulphur........................... 2 1/3 quarts
 Black leaf 40 ..................................... 3 1/2 ounces
 W ater ........................................................ 50 gallons
 Lead arsenate or zinc arsenite can be substituted for the
 lime-sulphur in case the grower wishes to kill the tomato worms
 or other biting insects at the same time. Four or five pounds
 of whale-oil soap may also be substituted for the lime-sulphur.
 Flour paste makes an excellent spreader for these tobacco ex-
 tracts. Take 2 pounds of cheap flour and stir it into 2 gallons
 of hot water. Add this paste to the 50 gallons of spray mate-
 rial.
 Since tomatoes should be regularly sprayed with bordeaux
 for fungus diseases, the best plan of all is to place the tobacco
 in the bordeaux solution.
 HORNWORMS (Phlegethontius quinquemaculata and P. sexta)
 Because of their large size, these insects attract the atten-
 tionh of the grower, but the total amount of damage actually
 dBne to the tomato crop is far less than in the case of any of
 the prfeeding insects. The moths of this family (Sphingidae)
 are known as sphinx moths," from the habit the larvae have
 of elevatilig the front end of the body when at rest, arching the
 head doin Alittle, and remaining perfectly immovable in this