1068 EXPERIMENT STATION RECORD. 



arrive at definite conclusions they must be continued for some time to 

 come. 



A general study of forest conditions and life zones has been begun,* 

 and a preliminary report is made of observations on the influence of 

 altitude on the distribution of plant and animal life. 



Brief notes are given on investigations made to determine and estab- 

 lish varieties of timothy and red clover and miscellaneous work in 

 investigating the San Jose scale, inspection of nurseries, the army 

 worm, a parasite of the rose aphis, the maple-twig borer, etc. 



Preliminary report upon the insect enemies of tobacco in 

 Florida, A. L. Quaintance (Florida Sta. Bui. 48, pp. 150-188, figs. 

 16). — The bulletin treats of the following insects which are injurious to 

 tobacco : 



The horn worm or tobacco worm (Protoparce celeus and P. Carolina). — 

 Of these two insects the latter is said to be far more abundant than the 

 former in Florida. The eggs are usually laid on the under surface of 

 the leaves and hatch in about 3 days. The larva requires 3 weeks to 

 attain its full growth. A description is given of the various stages of 

 the insect. 



As to treatment the author recommends hand picking, and gives 

 a long account of the use of Paris green in controlling this insect. 

 With regard to the danger from the use of Paris green on tobacco he 

 says: "It will probably be on the side of caution to use weak mixtures 

 of Paris green, as 1 lb. to 1(30 gal. of water. If this is applied properly 

 and at the right time, when the worms are young, it will be sufficiently 

 strong to kill them." If properly used, there should be no bad result 

 from the use of Paris green on tobacco. Arsenate of lead is also rec- 

 ommended to be used in the form of a powder to be applied by an 

 ordinary powder gun. Another remedy mentioned, which is said to be 

 very effective, consists in pouring a small quantity of a poisonous 

 mixture containing molasses into the flowers of the jimson weed, which 

 are much frequented by these insects. The adult insects will thus be 

 destroyed. 



Among the natural enemies of the tobacco worm the author mentions 

 a tachina fly (Sturmia sp.), Apanteles congregatus, and a brown wasp 

 (Polistes bellicosus). 



The suclc fly (Dicyphus minimus). — This insect, which was first noticed 

 in Florida in the year 1898, is said to be perhaps the most injurious 

 insect to tobacco in the State. The suck fly damages the tobacco by 

 sucking the juices from the leaves. The eggs are deposited in the 

 tissue of the leaves and hatch in about 4 days. A description is given 

 of the nymph and adult stages of the insect. The best remedy, in the 

 author's opinion, is a strong decoction of tobacco. Whale-oil soap was 

 tried, without good results. Kerosene emulsion and pyrethrum were 

 found to be rather effective. 



Cigarette beetle (Lasioderma sericome). — This insect is recorded as 

 being a very serious pest of stored tobacco in Florida and is said to 

 attack other materials, such as pepper, ginger, rhubarb, and upholstery, 



