112 Journal of Agricultural Research vol. xx, no. 2 



might have become established there long ago through the importation of 

 avocados or their seeds from some other part of the American Tropics. 



Miscellaneous information regarding the habits of the various stages of 

 the weevil was obtained in rearing it. Some notes regarding its economic 

 importance and distribution were also made. 



At Frijoles only the "wild" fruits were infested, 17 out of 40, or 42.5 

 per cent, of such fruits containing from 1 to 4 larvae. Out of over 200 

 cultivated fruits examined here not one was found infested. Fruits 

 infested with Heilipus larvae have been found on fruit stands in Panama 

 City and Colon, in the Republic of Panama, and at Gatun and Ancon, in 

 the Canal Zone. The only information obtainable in these cases regard- 

 ing the origin of such fruits was that they came either from the Canal Zone 

 or neighboring parts of the Republic of Panama. From the data at hand 

 the species seems to be limited to the "Canal Zone region," though there 

 is little doubt that it occurs over a much wider area. 



EGG PUNCTURES AND LARVAL HABITS 



The egg punctures are somewhat crescent shaped, about 4 mm. long, 

 with the ends blunt. In a general way they resemble those of the plum 

 curculio. As many as 10 were found on a single fruit, but in 8 of these 

 the eggs had been crushed by the growing fruit and in 2 young larvae had 

 hatched. No eggs were found, but from the examinations of infested 

 fruits it is evident that the eggs are laid at the junction of the skin of the 

 fruit and the pulp. The exact time that oviposition takes place is not 

 known, but from the evidence at hand it is when the fruit is between 

 one-half and three-fourths mature. 



After hatching, the larvae often wander through the pulp before entering 

 the seed, thus rendering a considerable part of the fruit inedible, especially 

 where more than one larva occur in it. Once the larvae enter a seed they 

 confine their activities to it. Mr. Barber has called attention to the fact 

 that seeds infested with H. lauri and H. pitiieri do germinate if the embryo 

 has not been injured by the tunnelling of the larvae, and the same thing 

 has been observed in the study of H. perseae; but when a seed becomes 

 infested with two or more larvae, it is usually so badly riddled that it can 

 not germinate. Furthermore, seeds infested with Heilipus larvae seem 

 to be subject to the attacks of several kinds of "dry rots" which follow 

 along the tunnels, invade the embryo, and kill it. Likewise, these fungi, 

 at least under laboratory conditions, seem to be indirectly responsible 

 for the death of a considerable number of larvae and pupae. 



No natural migration of larvae from one seed to another, even when 

 these seeds are massed together, has been observed, but half -grown 

 larvae taken from infested seeds immediately tunnelled into uninfested 

 ones when these were provided. 



The duration of the larval stage was not determined, but indications 

 are that it is not less than three months. 



