79 



on account of the injury due to A. rumicis, and also to prevent damage 

 and economise in time and spray material. A spray mixture that has 

 given good results consists of tobacco extract containing 40 per cent, 

 of nicotine sulphate 8 oz., fish-oil soap 3 lb., water 50 U.S. gals., the 

 mixture containing 1 part nicotine sulphate to 800 parts water. 



Other insects attacking the globe artichoke in Louisiana are : — 

 a bug, Leptoglossus phyllopus. L., the normal food-plant of which is the 

 yellow thistle, the larvae of Heliothis [Chloridea) obsoleta, F. (corn ear 

 worm), which bore into the edible heads, the plant-bugs, Thyreocoris 

 pulicarius Germ., and Nezara viridula, L., and a Scarabaeid beetle. 

 Euphoria sepulchralis, F. Cutworms, especially Feltia annexa, Treits., 

 and Agrotis ypsilon, Kott., cause some injury, especially during the 

 cooler months of the year. 



The larvae of two Agromyzid flies, Agmmyza platyptera, var. jucunda, 

 Wulp, and an unidentified species have been foimd mining in the 

 leaves, and a Membracid, Entylia sinnata, F., also breeds on them. 

 The foUage is also fed on to some extent by other insects, including 

 Phytometra (Autograpka) hrassicae, Riley (cabbage looper) and the 

 adult of Diabrotica (hiodecimjnmctata, 01. (southern corn root- worm). 



Feltia annexa, Treits. (granulated cutworm) is the principal cutworm 

 attacking vegetables in Louisiana, other species being Agrotis ypsilon, 

 Rott., and Feltia malefida, Gn. Practically all vegetable crops 

 are attacked. In the insectary eggs were deposited singly at night, 

 the number laid by individuals during the season varying from 5 to 

 1,106. The larvae, which feed at night, hiding by day in the soil 

 at the base of the plant, have been taken during all months except 

 March, May and September. There are 5 or 6 generations in the year, 

 and at times these overlap so that all stages are present simultaneously. 

 The length of time occupied by the combined egg, larval and pupal 

 stages depends on the temperature, the minimum recorded being 

 38 days in July and August. 



Natural enemies include the Tachinid, Linnaemyia comta, Fall., and 

 the Ichneumonid, Henicospihis purgatus. Say, both reared from larvae ; 

 while Sarcophaga helicis, Towns., which issued from a rearing jar 

 containing larvae, may have been parasitic on them. Dead larvae 

 infested with the fimgus, EntomophtJiora virescens, have also been found 

 in rearing cages. 



The best methods of control are by the use of poison-baits, and 

 by sprajang the plants with 2 lb. powdered lead arsenate to 50 U.S. 

 gals, water, with 2 lb. yellow laundry soap added. A poisoned 

 bait which gave good results was composed of bran 10 lb., molasses 1 

 U.S. quart, Paris green | lb., water 7 U.S. quarts, and the juice 

 and finely chopped rind and pulp of 2 oranges. A mixture of 20 lb. 

 bran, 2 lb. powdered lead arsenate, | U.S. gal. molasses and about 

 14 U.S. quarts of water, has also given good results in the field. 



In the last section details are given of spraying and dusting experi- 

 ments conducted during 19 IG and 1917 agamst Heliothis obsoleta, F. 

 (tomato fruit-worm). The sprays were apphed by means of small 

 compressed-air sprayers, the plants being treated 8 times for the spring 

 crop and 7 times for the autumn one of 1916, and 5 times in the spring 

 of 1917. For dusting a specially prepared, hght, finely powdered lead 

 arsenate was apphed the same number of times by means of a dust 

 gun. The very varied results of two years' work, however, show that 



