120 VEGETABLE GROWING IN NEW SOUTH WALES. 



French Bean Fly (Agromyza phoseoli). 



This little black fly, about one-twelfth of an inch in length, does a .^xxl 

 deal of damage to French bean crops in some districts. The fly lays its eggs 

 upon the stem near the ground, and the resultant maggots tunnel along under 

 the skin, leaving the stem rusty-red and cracked, so that the plant eventually 

 dies. 



Growers report that spring crops are seldom, if ever, damaged to any 

 appreciable extent, but as the weather becomes warmer the flies gradually 

 breed up and develop in such numbers as to be very destructive in the fall of 

 the year. 



In good growing weather some advantage is gained by hilling up the soil 

 round the plants, so that the stems are covered ; the bean plant then puts out 

 a fresh supply of fibrous roots above the damaged tissue. The hilling up also 

 protects the stems from attack if it is done before the flies first appear. No 

 spray or wash seems to have any effect upon the flies, and as the maggots do- 

 not feed upon the surface of the plant but under shelter of the tissue, no 

 poisonous spray would affect them. 



As with many other pests, this is a case for clean cultivation. The maggots 

 pnpate in the bean stems, from which, if the plants are allowed to remain in 

 the field, the flies emerge in due course. It would be advisable to pull and 

 burn all infested bean plants as soon as the last lot of beans has been gathered ; 

 otherwise, if the plants become dead and dry, pupae may drop out of the 

 cav ties in the stems, and, falling on the earth, remain in the ground 'long 

 after the dry stalks have been removed. 



Onion Maggot (Phorba ceparum). 



The worst insect pest of onions is the onion maggot. These maggots come 

 from eggs deposited on the plant, and require about a week to hatch ; the 

 larvae burrow into the bulbs and remain there about two weeks, then emerge 

 and pupate in the ground. Their presence is first indicated by the tops turn- 

 ing yellow, then withering, and finally drying before the bulbs have matured. 



It is difficult to suggest a remedy, but liming the soil is found to be 

 beneficial, and if the infestation is very severe, rotation of crops (see page 

 22) should be tried. 



Potato Moth (Phtkorimcea operculella] . 



This pest is more or less in evidence in every potato-growing district 

 throughout the State, and the loss caused by it annually is enormous. The 

 injury produced by the worm is extremely evident to the housekeeper (much 

 of the infected tuber being cut to waste) and is well-known to all dealers in 

 potatoes, but very generally they do not understand the nature of the insect 

 producing the trouble. The inj ury done to the plant in the field is considerable , 

 but not so great as that done to potatoes in store. 



Potatoes left in the field after the previous season's harvesting provide the 

 main harbour, and moths bred from these are on the wing and ready to 

 infect the growing crop. The moths usually lay their 'eggs in the 



