1914] Melon Fly, Dacus cucurbitae. 197 
Is there a difference in weight of the male and female melon 
flies upon emerging from the puparia? The following table 
shows the weights of two lots of flies shortly after the wings 
were expanded: 
TABLE VIII. 
WEIGHTS IN MILLIGRAMS OF MALE AND FEMALE MELON FLIES SHORTLY AFTER EMERG- 
ING FROM THE PUPARIA. 




Number of : Tat | Difference in weight 
fies Weight Weightlfly | Shao andee ay 
507 47.52 9504 
509 48.9 .978 .0276 
407 51. 1.275 
309 45.69 1.523 . 248 



It is evident from this table that the female melon flies are 
heavier, on an average, than the males shortly after they issue 
from the puparia. 
Sanit NATURAL ENEMIES. 
Predaceous insects sometimes prey upon the melon fly. At 
all times of the day the yellow dragon fly (Panatala flavescens 
Fab.) was observed flying over a pumpkin patch teaming with 
pest, and one would be inclined to believe that the melon flies 
are sometimes preyed upon by this predaceous insect. A 
number of dragon flies were captured in this field and the con- 
tents of their alimentary canal was examined, but no remains 
of the melon fly were found. A predaceous bug (Zelus peregri- 
nus Kirkaldy) was observed sucking out the juices of a melon 
fly onasunflower. Staphylinids or rove beetles were frequently 
seen within infested pumpkins but whether or not these feed 
upon the melon fly maggots was not determined. 
The European, horn fly parasite (Spalangia hirta Haliday) 
was bred from the puparia of the melon fly. These puparia 
were gathered from beneath infested pumpkins; some of these 
puparia were partly exposed from the ground; while others 
were taken from one to four inches below surface of the soil, 
the usual depth, however, being one to two inches. From five 
hundred puparia which were collected on March 25, three 
parasites emerged on May 4, 1912. It is evident that this 
parasite is of little importance in the control of the melon fly. — 
