THE MELON FLY IN HAWAII. 11 



trated in figure 3. Such destruction is almost complete in uncared- 

 for fields of all cucurbits except the cucumber, which rarely is at- 

 tacked until after the fruits are well set. 



Injury to the fruits after fertilization. — All degrees of injury will 

 be found among the fruits of host plants. The younger the fruits, 

 as a rule, the more susceptible they are to complete destruction by 

 the larvae and subsequent decays. If infestation is serious directly 

 after the bloom has withered, particularly among watermelons in a 

 dry location, a mummification of the fruits may result. (PL XI, 

 fig. 1.) The completeness with which the young watermelons may 

 be destroyed before mummification is shown by Plate XI, figure 2. 

 Still older watermelon fruits may become badly infested, as illus- 

 trated by the longitudinal section in Plate XII and the cross-section 

 in Plate XIII. In the latter the interior bearing the seeds had been 

 reduced to a watery mass and the larvae were found burrowing 

 through the rind. In fruits such as those illustrated in Plates XII 

 and XIII secondary decays soon bring about a complete destruction 

 of the host. 



The injury caused by the developing larvae may not be so great as 

 completely to destroy the host fruit. In such cases, especially among 

 pumpkins and squashes, which are apt to develop a corky protective 

 growth over the surface exposed by infestation, various and curious 

 deformities are produced as illustrated by the young fruits shown 

 in Plate XIV. In each of these fruits one or more colonies of melon- 

 fly larvae have reached maturity and emerged. The figures in Plates 

 XV and XVI illustrate several types of injury to very young 

 pumpkins. While these fruits will persist on the vines for several 

 weeks during dry weather, they ultimately succumb to the secondary 

 attacks of scavenger insects and decays. 



As the fruits become larger, before they are attacked, they may show 

 almost no indication of infestation to the casual observer, although 

 there never is any doubt in the mind of a trained observer. An 

 examination of such fruits may reveal the interior to be badly affected 

 and eaten out, although the exterior remains firm. This is probably 

 true more in the case of cucumbers and several varieties of Chinese 

 marrows (Momordica spp.), and less so of string beans, as illustrated 

 in Plate XVII. Injury to tomatoes, when the larvae become about 

 half grown, is usually accompanied by decay confined for some time 

 to the section of the fruit affected. 



Deformities resulting from punctures of the epidermis when no 

 eggs are deposited, or from infestations by larvce or eggs in only the 

 outer portion of the rind. — Deformities of all sorts are produced in 

 cucumbers and pumpkins which have been attacked late in their 

 development. Deformities among watermelons have been noted by 



