170 STATE HORTICULTURAL SOCIETY. 



of n^p totnl effffs are depositerl durinsf the first two weeks; one-half have 

 been deposited bv the close of the first month : three-fonrths within six 

 wee^s- and abont 88 per cent of the total within eight weeks after the 

 ovioosition begins. 



Time spent in the fruit. — Records of the time spent in the frnit as 

 the esrg and larva have been determined for many individuals and in 

 various localties. including Illinois. District of Columbia, western New 

 York. Georgia, Arkansas and Michigan. 



Tn all localities the maiority of the llarvae emerged within three 

 weeks after the eggs were laid, and, with one exception, emergence bad 

 practically cased by the close of the fourth week. 



Time svent in the so?7.— When full grown the larva deserts the fruit 

 and burrows below the surface of the soil. Practically none of the 

 larvfP go deeper than 3 inches and the great majority penetrate not 

 more than 2 inches. A small cell is made where the punal stage is 

 passed and where transformation to the adult or beetle occurs. Some 

 days are spent in the soil by the larva before changing to the pupa, 

 and the newly formed adult may not emerge for several days or even 

 weeks, especially if the ground be dry. The effect of a shower, however, 

 is to bring the new-generation beetles out in numbers. 



A large number of observations have also been made on the length 

 of time spent in the soil by different individuals, including a total 

 of several thousand and from about the same localities as already men- 

 tioned. All of these observations go to show that comparatively few 

 insects complete their underground transformations in less than three 

 weeks from the time of entering the soil as larvse. In from four to five 

 weeks, however, the great majority of the beetles are out and by the 

 close of the sixth week emergence has practically ceased. 



Time required for transformation from egg to adult. — The average 

 time spent in the fruit for the numerous localities investigated proved 

 to be 19.48 days, and the average time spent in the ground was found 

 to be 30.89 days, giving an average life-cycle period for the insect of 50.27 

 days. 



Comnlete life-cycle observations were also made on a total of 597 in- 

 dividuals from many parts of the country, which gave a final average 

 for the period per individuall of 50.71 days, differing only a fraction 

 of a day from the time determined in an essentially different manner. 

 Approximately 50 days would therefore appear to be the average life- 

 cycle period for the plum curculio for the country as a whole. The 

 range though, will vary considerably and as actually determined in the 

 case of the individual records was from 37 to 58.45 days. 



Hahits of heetlcs from emergence u/ntil hihernation. — After emer- 

 gence, beetles of the new generation feed upon various fruits and plants 

 until fall, when they enter hibernation quarters, appearing the follow- 

 ing spring, as already stated. While there is some evidence to indi- 

 cate that there may be a small generation in the South, this will be 

 comparatively insignificant and for practical purposes the insect pro- 

 duces but one generation annually. The beetles which develop one 

 summer live over the following winter, ovipositing during the spring 

 and summer, and gradually die off, until by early fall practically all 

 of them have disappeared. The life of the more hardy beetles. is thus 

 seen to be some 12 or 14 months. 



