21 



Other contact insecticides giving good results are : Proprietary 

 miscible oils and emulsions ; soaps ; kerosene emulsion ; kerosene- 

 lime mixture, composed of kerosene (42° Be.) 20 U.S. gals., unslaked 

 lime 40 lb., water 200 U.S. gals. ; lime-sulphur solution ; and tobacco 

 extract. 



Newell (W.). Sweet Potato Root VJeevil.—Qlrl^. Bull. Florida State 

 Plant Board, Gainesville, ii, no. 1, October 1917, pp. 81-100, 

 2 figs. [Received 13th November 1918.] 



Cylas formicarius F. (sweet potato root- weevil) is a pest that for 

 many years has severely injured, and in many cases totally destroyed, 

 the sweet potato crop in certain parts of Florida. This paper gives a 

 full account of its history, distribution, life-history, host-plants, and 

 methods of dissemination, as well as natural and artificial remedial 

 measures [see also this Review, Ser. A, i, p. 217 ; iii, p. 461 ; v, p. 313]. 



Experiments have been begun aiming at the complete eradication 

 of this pest when occurring in isolated outbreaks. The method 

 employed consists in : (1) spraying the entire field with kerosene to 

 destroy any adult weevils ; (2) cutting and burning all potato vines 

 on a log fire ; (3) carefully digging out and burning all tubers and as 

 many roots as possible ; (4) ploughing the field and picking and burning 

 all pieces of sweet potato plant ; (5) harrowing the field several times 

 and repeating the picking out process ; (6) partly burying in various 

 parts of the field clean sweet potatoes to act as traps, visiting these 

 daily to destroy the adult weevils, burning the traps each week to 

 destroy any eggs deposited on them, and replacing them by fresh 

 ones, this practice being continued for the rest of the season. 



HoYT (A. S.). The Avocado Weevil {Heilipus lauri, Boh.) — Qtrly. 

 Bull. Florida State Plant Board, Gainesville, ii, no. 2, Januarv 

 1918, pp. 108-112, 3 figs. [Received 13th November 1918.] 



The development of the avocado industry in California in the years 

 1912-1913 led to the issue of quarantine regulations both in that 

 State and in Florida prohibiting the importation of avocado seeds 

 from Mexico and Central America, since large quantities of seeds had 

 to be destroyed or refused landing owing to the presence of Heilipus 

 lauri. Boh. (avocado weevil), Cauhphilus latinasus, Say (broad- 

 nosed grain weevil), Araecerus fasciculatus, De G. (coffee-bean weevil) 

 and a small Scolytid beetle. 



In captivity the adult weevil will feed upon the fruit, leaves, stem 

 and seeds, even attacking the hard surface of a thoroughly dry seed. 

 It is practically impossible to detect the presence of the larva within 

 the seed, and fumigation for 6 hours in an atmosphere saturated 

 with carbon bisulphide fails to destroy it. Experimental fumigation 

 in a partial vacuum has given very encouraging results, but the method 

 has not yet been recommended as a means of modifying the avocado 

 seed quarantine. Empowered to enforce the rules and regulations 

 of the Federal Horticultural Board, it is now the duty of the port and 

 railway inspectors of Florida and the quarantine officers of California 

 to do their part in preventing this weevil from establishing itself in 

 these States. 



