THE FRUIT SIIKD IN RKLATIOxX TO Tllli CODLING MOTH. I95 



practical to fumigate thcni. even if funii,e^ation were a successful 

 nictliod of control. 



To determine how closely the emergence of Spring moths 

 in a fruit shed with thatched roof and Ijrick walls compared with 

 the emergence of Spring moths under out-of-doors conditions, 

 observations were made at h^lsenburg during 19 17. The shed 

 was kept closed as much as possible, but on several occasions it 

 was found to have been left open by native labourers during 

 the day. The record.s, which are illustrated in the chart 

 on p. 194, show that the, approximately. 200 mollis emerging in 

 the fruit .shed appeared about six weeks later than 568 moths 

 emerging under normal out-of-doors climatic conditions. Con- 

 sequently, had the packing shed moths flown to the orchard, the 

 larvae hatching from the eggs laid by them would have been 

 difTicult to control, firstly, because the spray apjjlications would 

 not have been timed to destroy them, and, secondly, because the 

 later eggs hatch the greater will be the percentage of larvae 

 which attempt to enter the sides of the fruit, where they are 

 poisoned with less success than in the calyx cup. Such a condi- 

 tion might easily result if a fruit shed were to be kept closed a 

 part of the time and opened occasionally during the period of 

 moth emergence. 



In view of the unsuccessful results of destruction bv fumi- 

 gation of hibernating larvae in fruit sheds, the frequent imprac- 

 ticability of screening of the packing house, or the prevention of 

 the escape of the moths, and the possibility of the emergence in 

 fruit sheds of the Spring moths — under certain conditions, not 

 coinciding with their appearance in the orchard under natural 

 out-of-doors conditions, when fruit sheds are not so constructed 

 that they can be kept closed to the exit of moths from September 

 to the end of the fruit season — they should be kept as open as 

 possible, day and night, in order that the moths may emerge at 

 the same time as under normal conditions, and in order that the 

 spray applications may be timed to control their progeny as well 

 as the progeu)- of those moths emerging in the orchard. It 

 should be emphasised, however, that fruit sheds should be so 

 constructed that they can be effectively closed to the exit of 

 moths. 



The sorting and temporary deposition of the infested fruit 

 of the packing house in shallow, open pens so constructed that 

 there are no cracks in the floor or sides, and surrounded by 

 strips of hessTan or loose boards full of crevices so arranged as 

 to attract the larva; leaving the infested fruit to these traps for 

 shelter, where the cocoons r<jay be periodically collected and 

 destroyed during the fruit season, might be of advantage in 

 fruit sheds which cannot be closed to the exit of moths. During 

 the winter months all cracks and corners in such open houses 

 should be examined thoroughly and all cocoons found should be 

 crushed or destroyed. 



