VEGETABLE i ROPS. 689 



the plants to weaken and wilt. Towards the end of summer, winged forms 

 are developed more numerously, and the aphides spread. Winged males are 

 also now developed and fertilise the females, which then lay eggs known as 

 the winter eggs. These eggs tide the winter over and hatch in the follow- 

 ing spring to start the broods of that season. 



Controls. — Spray with tobacco and soap wash, or sunlight soap wash, or 

 even a dilute kerosene and soap wash, say, 1 part of kerosene to 30 parts of 

 water; the mixture must be very thoroughly emulsified with soap to prevent 

 burning of the tender parts of the flowers and foliage. Further, it is 

 recommended that stubble and weeds in the bean fields be thoroughly 

 destroyed or well turned in to destroy any aphis or eggs. 



Peas are attacked by an aphis which may be controlled in the same way 

 as bean aphis. 



Green Bug. 



These plant juice-sucking bugs (Cuspicona) are sometimes numerous and' 

 destructive. They are wide-bodied, green bugs, about one-third of an inch 

 long, with a triangular plate or shield in the middle of the back. 



Controls. — Oil spraying is not so effective as hand-picking, i.e., collecting 

 them by hand (preferably in early morning), and destroying the limited 

 number which may be present. The use, as follows, of a tray of oil and 

 water can also be recommended. A shallow iron trough, 1 foot or 18 inches 

 wide, 2 or 3 inches deep, and about 3 or 4 feet long is made; a sheet of 

 galvanized iron may be used, the ends and sides being turned up and 

 soldered. About a cupful of kerosene or other oil and half a gallon of 

 water are poured into the tray, which is then drawn slowly along betw.een 

 the rows, while someone follows behind and beats or brushes the bean plants 

 with a bundle of brush, dislodging numbers of the bugs, which usually fall 

 into the trough of oily water. Repeated two or three times, say, once every 

 four to seven days, the limited number of bugs present may be much 

 reduced. 



Tomato and Bean Bug. 



The distinctive bright green and unmistakable shield form of this plant" 

 bug (Nezara viridula) have become quite familiar to vegetable growers in- 

 coastal districts, where it is now known as a pest on the fruits and foliage 

 of the tomato, on the foliage and young pods of French beans, and on the 

 foliage of potato plants. In Florida, U.S.A., the species is known as a pest 

 of orange trees, and in some districts of New South Wales it has acted 

 similarly. They damage plants by sucking the plant juices from the ten- 

 derest parts. 



The accompanying plate illustrates the typical shield shape. The insect 

 can run and fly very well, but it generally drops to the ground when the 

 plant is disturbed. The female lays her eggs in little patches on the surface 

 of the foliage of the young beans, and the baby bugs, when ready to emerge, 

 push off the flattened lid. leaving the empty eggs like tiny glass cups. The- 

 bugs are dark-coloured when they first emerge, but during successive moults 

 they gradually change to a lighter colour until they appear as the perfect 

 green shield bugs. They may be present among the foliage of a plant in 

 numbers, and yet escape detection, so closely does their colour harmonise 

 with the background. 



Controls. — The clusters of round, flat-topped, glassy eggs are very notice- 

 able on the foliage, and if the infested leaves are snipped off and destroyed 

 large numbers can be destroyed before they even hatch. If the bugs are- 

 noticed on plants, a sheet could be spread on the ground and the plants- 



