1914] Melon Fly, Dacus cucurbitae. 189 
tion and it required seven and nine minutes respectively to 
complete the egg laying period. 
14. Number of eggs deposited in a receptacle-—The number 
of eggs which the pest lays within a receptacle varies from one 
to forty. The insect often punctures various parts of the host 
plant with its ovipositor and yet does not deposit any eggs. 
15. Number of ripe eggs in ovaries.—-In order to ascertain 
the number of ripe eggs present in the ovaries, eighteen melon 
flies were captured in the field and dissected. The average 
number of mature eggs found in the two ovaries was forty- 
eight; the largest number of fully-developed eggs dissected from 
one specimen was seventy-four and the smallest number ob- 
tained from an individual was twenty-two. The number of 
eggs which one female is able to lay during its natural life was 
not determined. 
16. Duration of the egg, larval and pupal periods.—After 
melon flies had been induced to oviposit in pumpkins, squash, 
egg plants, tomatoes, cucumbers and string beans in the field, 
the vegetables were transferred to breeding jars and a careful 
record was taken of the different periods of the life history. 
The following table shows the duration of the egg, larval, and 
pupal periods of Dacus: 




TABLE I. 
DURATION OF THE EGG, LARVAL, AND PUPAL PERIODS OF DACUS CUCURBIT. 
Fost Egg period Larval period Pupal period 
(hours) (days) (days) 
[2xbomeholsciknt, Uae oleae olor 30 4-7 10-13 
WQUASaMer. ake 32 5-7 11-14 
Sonoita weet een. 2 31 5-11 12-14 
AROMALTOU Re tren eee: 36 5-8 12-13 
CGucumbere ssn. 2 33 5-9 12-14 
Stringsbean: ayn... 31 5-10 11-12 



17. The effect of temperature on the egg period.—Pumpkins 
containing eggs which had been recently laid were exposed to 
the hot sunshine, while others were kept in the shade under 
field conditions, but no marked difference in the duration of the 
egg period was observed. 
18. The effect of decay of food on the rate of development of 
the larve.—One important factor upon which the rate of develop- 
ment of the melon fly larve depends, is the rapidity of decay of 
