309 



only known to occur in New Orleans, where it was apparently introduced 

 on roses and has spread very rapidly [R.A.E., A, x, 73]. During a 

 severe storm, scales were blown to a point two miles from the original 

 infestation. A survey showed- that about four square miles are 

 infested. Outside the original infested area 450 isolated infestations 

 were found, all of which were cleaned up. During a series of experiments 

 to find a satisfactory spray, lime-sulphur, miscible oils and numerous 

 other preparations were tried without success. Eventually all the trees 

 in the infested area- were defoliated by pruning out all the branches 

 and hmbs bearing leaves, and the trees were sprayed with a 2 per cent, 

 emulsion consisting of 2 lb. potash fish-oil soap, 2 U.S. gals, junior 

 red engine-oil (standard oil product) and 1 U.S. gal. water. This 

 preparation gave 100 per cent, control. It is proposed to spray twice a 

 year. Although very resistant to various spray materials, this scale 

 is particularly susceptible to h^'drocyanic acid gas, the gas from one 

 ounce of sodium cyanide to 1,000 cubic feet killing all scales. Plants 

 in flower withstood this treatment for one hour at a temperature of 

 85-92° F., provided they were placed in the shade after treatment. 



The males of this species are alwa\s found on the leaves, and the 

 females on the twigs. About 200-250 eggs are deposited over a period 

 of about a month. Ants are generally present in large numbers where 

 the scales occur. About eight species of parasites and predators have 

 been found, but it is doubtful whether they cause a two per cent, 

 mortality. It only requires a few scales to cause complete defoliation 

 of a twig, and the whole tree may die six months after attack. 



There are 172 species of food-plants, the more susceptible of which 

 are camphor, fig, rose, hackberry, elm, and Citrus. The injury is not 

 confined to tropical and semi-tropical plants, and this scale must be 

 regarded as a potential pest in latitudes north of New Orleans until 

 the contrary has been proved. A quarantine against it has been in 

 force since June 1921, and includes all territory within a radius of 

 20 miles around New Orleans. Plants that had left the infested area 

 before the infestation had been discovered are now being traced, but 

 this work is progressing very slowly owing to lack of funds. 



A great deal of the information concerning the Mexican bean beetle 

 [Epilachna corrupta, Muls.] has already been noticed [R.A.E., A, 

 ix, 374]. It is now certain that it was introduced into Alabama from 

 Utah with lucerne hay. Careful search in Mexico has revealed only 

 one parasite of this beetle, a Tachinid fl\\ The present range of the 

 beetle includes 36 counties in Georgia, 34 in Alabama, 34 in Tennessee, 

 and 2 in Kentucky, North Carolina and South Carolina. 



The chief factors in the control of the sweet potato weevil [Cylas 

 formicariiis, F.] are the control of seed and slips to be planted in the 

 infested area, and clean cultivation. Eradication work has involved 

 about 900 farms, and out of 300 in Florida only 30 remain infested. 

 Scouting for the pest should be done in the autumn at harvest time, 

 and in the spring when the potatoes are to be bedded. Wild morning 

 glory is an alternative food-plant, but the presence of wild food-plants 

 is of less importance than the climate. Five miles is considered to 

 be ample for a safety zone around an infestation, the main point 

 being to prevent the pest being carried in seed. 



The Argentine ant [ Iridoinyrmex humilis, Mayr] causes an annual 

 loss of not less than /5,000,000, and it has been estimated that this 

 is only about one per cent, of what it is capable of doing. Eradication 

 is now being carried out at New Orleans and Baton Rouge on a large 

 scale, about 150 cans of poison being used to a city block. The complete 



