114 [ DISEASES OP THE OLIVE TREE 



side. The abdomen, the antennae and the feet are 

 yellow. The larva is half a centimetre in length, white or 

 dirty white, with two moveable hooks at its head, with 

 which it gnaws its way into the pulp of the fruit. The 

 pupa or chrysalis is about 4 millimetres long, at first 

 dirty white and then dull yellow. The female insect has 

 an ovipositor at the end of the abdomen with which it 

 perforates the rind of the green fruit and deposits an egg 

 in each fruit; but the same fruit may be visited by two or 

 more insects and therefore may contain two or more 

 larvae. The insect flits on from one fruit to another 

 depositing an egg in each, until it has laid between 50 

 and 150 eggs, destroying as many fruits. According to 

 some writers the number of eggs laid by one insect may 

 even be 300 or 400. In two or three days the eggs are 

 hatched, and the larvae after tunnelling into the pulp 

 and feeding upon it, reach maturity in 14 to 20 days 

 and drop down from the fruit, or come out of it, if in 

 the meantime the fruit has dropped from the tree, and 

 hide themselves in the earth or in the crevices of the 

 bark of the trunk and transform themselves into pupae. 

 From these in about 1 2 days emerge the perfect insects, 

 so that the olive-fly takes from 28 to 35 days to develop 

 from the egg to the perfect insect, and as the insect 

 begins laying eggs in July and continues in activity until 

 late in autumn, there may be three or four broods every 

 year, in the meantime the havoc increasing more or less 

 in geometrical proportion. 



After a severe winter or a prolonged cold spring the 

 attack of the olive-fly is usually slight, as most of the 

 hibernating pupae are killed by the cold; and an attack 

 which was , particularly threatening in August may be 

 greatly mitigated by successive heavy showers of rain 

 in September, which wash down and kill the flies of the 

 2nd or 3rd brood before they have time to lay eggs. It 

 is also noticed that on irrigated lands the olive is less 

 liable to the attacks of the olive-fly, probably because 



