MEDITERRANEAN FRUIT FLY IN HAWAII. 105 



measures. Dr. Trabut found that in Algeria the infestation of oranges 

 greatly increased after the introduction of such crops as peaches and 

 persimmons, since these fruits furnished food for the fly during the 

 summer and early fall months, which for the fruit fly had been starva- 

 tion months previous to the cultivation of these fruits. Aided by 

 these introduced summer crops, the fruit fly was able greatly to 

 increase, so that when the orange crop began to ripen during the 

 fall and winter months, the pest could attack it with increased force. 

 The ehmination of a comparatively few host trees, numerically speak- 

 ing, in Bermuda would mean the ehmination of breeding places over 

 considerable areas. The destruction of unnecessary and valueless 

 host trees serves to restrict the breeding ground, as well as to destroy 

 the sequence of ripening hosts so that many adult flies will die while 

 attempting to bridge the ensuing starvation periods, during which 

 no host fruits can be found for oviposition. 



SPRAYING. 



It has been demonstrated that the Mediterranean fruit fly must 

 feed for about four days after emergence in the warmer months 

 before the females are capable of ovipositing in fruits. This feed- 

 ing period may be extended to 10 days during winter in littoral 

 Hawaii. Although the interval between emergence and oviposition 

 is short, it offers the best opportunity to kill this pest by means of 

 poisoned baits or sprays. Mally, in South Africa, first appreciated 

 the vulnerability of this point in the life cycle and developed and 

 demonstrated the value of poison sprays as a factor in the control of 

 the Mediterranean fruit fly. Berlese, in Italy, however, working 

 quite as independently, carried out similar experiments to check the 

 olive fly (Dacus oleae). Equal credit is due Mally and Berlese for 

 the use of poison sprays in combating fruit flies. 



The results of the experimental work of Mally during 1904-5 and 

 of Dewar during 1915 were not successful, although encouraging. 

 The later work of Mally during 1908-9 proved conclusively the value 

 of poison sprays under South African conditions. Mally states that 

 "a severe outbreak of the pest in a commercial peach orchard was 

 brought to a sudden and practically complete halt, and the fruit 

 maturing later was marked under the guarantee of freedom from 

 maggots," while the infestation among fruits on check trees increased 

 until practically all fruits had become infested. These experiments 

 lead Mally to state that Ceratitis capitata can be controlled most 

 perfectly under orchard conditions by means of a light sprinkling of a 

 poisoned sweet over the trees just before or during the ripening 

 period of the fruit. In 1912 Lounsbury demonstrated the applica- 

 bility of the poison spray under town conditions in South Africa during 

 most unfavorable weather conditions, and concluded that if spray- 



