58 EXPERIMENT STATION RECORD. [Vol.40 



the increasing demand for edible heads of which led to the studies here reported. 

 The most serious injury to this vegetable in Louisiana is said to be caused by 

 two species of plant lice, namely, the artichoke aphis (Myzus braggii) and the 

 bean aphis (Aphis rumicis), both of which usually occur in the same field and 

 are most numerous during the late winter and in the spring. The artichoke 

 aphis is the most common and the most injurious insect enemy of the globe arti- 

 choke in Louisiana. No parasites have been found to attack this species but 

 several predators have been observed, a list of which is here presented. At 

 Baton Rouge Scymnus puncticollis appears to be the most efficient. Jf. braggii 

 also infests the yellow thistle (Carduus spitwsi^simus=Cirsium horridulum), a 

 common weed in Louisiana. 



A. rumicis, while not as common as M. braggii, is more difficult to control by 

 spraying, largely because of the fact that infested leaves become distorted in 

 such a manner that the aphids can be reached only with difficulty with a contact 

 insecticide. In work during 1917 both species were satisfactorily controlled by 

 spraying with one part, by weight, of nicotin solution (40 per cent nicotin Bul- 

 phate) to 1,000 parts of water, with laundry soap added at the rate of 1 lb. to 

 25 gal. of water. A company in Plaquemines Parish, which annually grows from 

 10 to 15 acres of globe artichokes, has found that the aphids are killed su<< ess 

 fully by a nicotin spray, consisting of tobacco extract containing 40 per cent 

 nicotin as sulphate, S oz. ; fish-oil soap, 3 lbs.; and water, 50 gal. 



Other insects mentioned as attacking globe artichoke in Louisiana include 

 the banded leaf-footed plant bug (Leptoglossus phyllop-us), the bollworm. a plant 

 bug {Thyreoooris pulicarius), Nezara viridula, a searab.-eid beetle (Euphoria 

 sepulchralis) , cutworms (particularly Fcltia annesca and the black cutworm), 

 the larvae of two agromyzid flies (Agromyza platyptera jucunda and Agromyza 

 sp.)i a membracid (Enli/lia sinuata), the larva of the cabbage looper, and the 

 adult of the southern corn rootworm (Diabrotica duodeeimpunetata). 



II. The granulated cutworm, an important enemy of vegetable crops in Lou- 

 isiana (pp. 7-14). — Observations by the author indicate that the granulated cut- 

 worm (F. anncxa) is the principal cutworm which attacks vegetable crops in 

 Louisiana. Of 1.431 cutworms collected from April to December in 1915, 1916, 

 and 1917. 1,345 (94 per cent) were identified as F. annera, the Mack cutworm 

 being second in number (3.2 per cent) and F. malefida third (2.5 per cent). 



The most serious damage caused by the granulated cutworm is that due to 

 its habit of cutting off small plants near the surface of the ground. Irish pota- 

 toes, beets, and Brussels sprouts have been observed to be defoliated, while the 

 fruit of tomato and eggplant resting on the ground are sometimes bored into and 

 made unsalable. 



Technical descriptions of the several stages of this species are reproduced, 

 followed by a report of studies of its life history and habits. A list of crops 

 observed by the author to have been injured include bean, beet. Brussels sprouts, 

 cabbage, cauliflower, eggplant, Irish potato, pepper, tomato, and turnip. Records 

 of oviposition of individual females show from 311 to 1,374 e^s to have been 

 deposited, as many as 307 having been deposited during a single night. During 

 December eggs were deposited on a night when the thermograph registered as 

 low as 19° F. In the locality of Baton Rouge, there are apparently live and 

 possibly six generations a year, these so overlapping that at certain times all 

 stages are present in the field simultaneously. The length of the ej - Btage 

 varied from 4 days in July to 54 in December and January. Pupation may take 

 place in August as soon as 24 days after emergence from the egg and the pupal 

 stage is passed during August within 10 days. The minimum pori.nl for 

 larva, and pupa stages combined was as low as 3S days during July and August 



