58 THE FLORIDA ENTOMOLOGIST 
aphidis (identified by Dr. Roland Thaxter of Harvard). This 
disease was so serious, in fact, that it interfered with the breed- 
ing experiments which were being carried on there by killing off 
the aphids. It was also found on the aphids outside both in the 
spring and summer months. On one occasion it was so common 
that the under sides of the pansy leaves were covered with the 
dead bodies of the aphids. Suitable weather conditions are nec- 
essary for it to grow well and this is the reason it killed off all the 
aphids in the greenhouse where it is warm and humid. Undoubt- 
edly this disease accounts largely for the disappearance of these 
insects during the summer for the warm humid climate of the 
rainy season is conducive to its growth. An interesting feature 
of this fungus is that it does not grow on other species of aphids. 
Several attempts were made to grow it on Aphis gossypii on 
orange trees in the greenhouse and under the same conditions as 
when it was growing on Myzus persicae on cabbages, but without 
suecess. The dead bodies covered with spores were rubbed over 
the bodies of Aphis gossypvi and leaves with them were pinned to 
orange leaves containing Aphis gossypvi, but in no cases could it 
be made to grow on other aphids, and never have any instances 
been observed under natural conditions where other species of 
aphids were attacked by it. 
An internal hymenopterous parasite, Diaeretus rapae Curt. 
often parasitized this aphid very severely. The insects fly about 
and deposit their eggs in the bodies of the aphids by piercing them 
with their ovipositor. Two species of Syrphus flies were found 
feeding on the aphids, and also the lace-winged fly, Chrysopa 
oculata and a lady beetle, Chilocorus bivulnerus. 
ALPHIS GOSSYPII Glover 
Aphis gossypii commonly known as the melon louse, is perhaps 
the most important aphid in the State from an economic stand- 
point, and also one of the most numerous. It occurs in all seasons 
of the year and some observations were made as to its hosts and 
method of living through the year. An interesting fact about 
this aphid is the many forms in which it occurs. The citrus form 
is a dark slate color or velvety green, while it usually occurs on 
melons in a yellowish form. However, the yellow, melon form 
is also occasionally seen on orange trees. These forms are so 
radically different as to be hardly recognizable as the same 
species, in fact they were called different species for many years 
and known as the citrus aphid, the melon aphid, and the cotton 
