14 BULLETIN 491, U. S. DEPARTMENT OF AGRICULTURE. 



is so general during the warmer months that data are superfluous. 

 The tomato under climatic conditions less fa Adorable for the increase 

 of the melon fly would probably be found to be less susceptible to 

 attack than cucurbitaceous crops. The fruits of the currant tomato 

 (Solanum pirn pinelli folium), the grape tomato (S. lycopersieiim) , 

 the popolo (S. nodiflorum) . and the spiny yellow- fruited Solanum 

 common in Hawaii are all found growing about fields of cucurbi- 

 taceous crops, but the writers have never yet found them infested. 

 During January and February the writers have seen fields of toma- 

 toes producing a large percentage of sound fruits. Only the fruits 

 of the tomato are subject to attack. 



STRING BEANS. 



The ordinary varieties of string beans grown on the mainland are 

 not as a rule infested by the melon fly. Three hundred and seventy- 

 five pods sufficiently ripe to have turned color, of the variety com- 

 monly known as the yellow wax bean, were examined at Haleiwa 

 in March and were found free from attack, although growing close 

 to a field of badly affected pumpkins. Examinations of string 

 beans in other localities, particularly about Honolulu, indicate that 

 only seldom are any of the varieties affected except the more fleshy, 

 long-podded Chinese variety. This variety may be very badly 

 attacked when grown near other favored host fruits or on land 

 recently cleared of such crops. (See PL XVII.) As many as 36 

 well-grown larva? have been found within a single pod. 



Although the Chinese variety is the only one at times generally 

 and badly affected, beans of all varieties except the lima bean should 

 be included in quarantine lists. The lima bean has never been 

 found infested. Only the pods of beans are usually affected. The 

 larvae prefer to feed upon the fleshy portions of the pod, but some- 

 times attack the seeds. In badly infested pods, attacked before the 

 seeds are well grown, the larvae may eat out the seeds, leaving the 

 outer portion untouched. This is also true of cowpeas. 



COWPEAS. 



Although cowpeas are not grown to any extent in Hawaii, they 

 are subject to melon-fly attack.- Only the pods are affected. The 

 writers have removed as many as 37 larvae from a single pod. When 

 infestation occurs early the young seeds ma} T be devoured, but 

 attack is more often centered upon the pod itself. There is a dis- 

 tinct varietal difference in the susceptibility of cowpeas. Upon this 

 notes were made, but unfortunately have been lost. 



