248 



Hbn. (bollworm), the butterfly, Uranotes melinus, Hbn. (cotton 

 square borer), Prodenia ornithogaUi, Guen. (cotton-boll cutworm), and 

 Dysderctis suturellus (cotton stainer). Bugs that attack the squares 

 and bolls include Adelphocoris rapidus, Say, Leptoglossus phyllopus, L., 

 Largus succinctus, L., Nezara hilaris, Say, and Jadera haeniatoloma^ 

 Schf. Flower beetles, which when numerous damage the blooms, 

 include Epicauta vittata, F., E. lemniscata, F., E, cinerea, Forst., 

 E, ferruginea, Say, etc, and Chaidiognathus spp. (soldier beetles). 

 Injuries to the stalk and roots are caused by wireworms, such as 

 Monocrepidius vespertinus, F., Horistonotus uhleri, Horn, Aphis 

 maidiradicis, Forbes (corn root aphis), Papaipema tiebris, Guen. 

 {nitela, Guen.) (moth stalk-borer), Ataxia crypta (cotton stalk-borer 

 beetle), Oecanthus niveus, De G. (snowy tree cricket) and leafhoppers, 

 including Homalodisca triquetra, F., Oncometopia undata, F., 0. lateralis^ 

 F., and Aulacizes irrorata, F. Ants in the cotton field may be either 

 beneficial or injurious. Such large species as Atta iexana, Buckley, 

 and Pogonomyrmex barbatus malefaciens, Buckley, should be destroyed ; 

 but several of the smaller species of ants, particularly those of the 

 genera Solenopsis, Pheidole, Monofnorium and Iridowyrmex, are very 

 efficient enemies of the boll weevil and are probably on the whole 

 beneficial, although they encourage Aphids, whiteflies and scales. 



A single system for cotton-insect control is described, the measures 

 for each season being indicated. In early spring weeds should be 

 kept dowm and poison-bait traps laid wherever necessary for cutworms, 

 grasshoppers, May beetles, etc. Planting should be as early as possible, 

 while avoiding frosts ; prolific varieties that fruit rapidly should be 

 chosen to suit the locality. For summer treatment, cultivation 

 should be continued until the crop is gathered or as long as possible. 

 With the first sign of attack by caterpillars plants should be dusted 

 with powdered lead arsenate. In the autumn the cotton crop should 

 be gathered without delay and then the plants destroyed by ploughing 

 imder or grazing as long before frost as possible. It is advisable to 

 follow a three-year rotation wath cotton following some crop other 

 than maize. In winter all fence rows should be cleared, weeds cut 

 and burnt, stubble fields ploughed and old stumps rooted up. 



GuNN (D.). The Small Cabbage Moth {Plutella niacuUpennis, Curtis). 

 • — Union S. Africa Dept. Agric, Pretoria, Bull. no. 8, 1917, 10 pp., 

 8 figs. [Received 15th April 1918.] 



Plutella macidiptennis, Curtis (small cabbage moth) is a widespread 

 pest of cabbage, cauliflower, stocks and other cruciferous plants in 

 South Africa. The insect is entirely dependent vipon meteorological 

 conditions for its existence ; in dry seasons it is abundant, but heavy 

 rains destroy large quantities, and it is, very sensitive to moisture. 

 Eggs are laid on the leaves, usually on the upper surface near the veins, 

 where they occur in clusters. In warm weather they hatch in about 

 five days, the young larvae feeding upon the under-side of the leaf 

 and soon dispersing all over the plant. A gauze-like web is spun 

 over the spot on the leaf on which the larva is feeding, and here 

 after 15 to 18 days the cocoon is made. The pupal stage occupies 

 5 to 7 days in summer and about 14 days in winter. It was previously 

 thought that hibernation occurred in this stage, but this supposition 



