82 Annals Entomological Society of America  [Vol. VII, 
its cocoon. This species of Dinocampus seems to consist 
entirely of females, as no males were found, even though 
individuals were bred from females in the Insectary. 
The third species of ladybird is much smaller than either of 
the other two but has a life-cycle similar to the others. No 
exact records were obtained as to the number of Aphids eaten 
but it was found that the average life, from the egg until the 
adult dies is about five to six months. One peculiarity noted 
was that the eggs were not laid on end as is generally the case 
with ladybirds, but rested on their sides on the leaf in little 
heaps. This little ladybird is very severely parasitized by a 
Chalcid belonging to the genus Homalotylus. The parasite 
is usually bred from the larva collected in the field. In the 
month of October, about 25% of the larvae seemed to be para- 
sitized. From three to seven eggs are laid by the parasite in 
one larva and the ladybird larva usually hangs itself up as 
though about to pupate before dying. The larva of the para- 
site pupates in the dead body of the ladybird larva. 
This Chalcid will also breed in captivity in both the other 
species of ladybird, but has not been bred from either of them 
in the field. 
The little Black Ladybird is most beneficial during the 
spring and autumn when the cold affects the parasite more than 
it does the ladybird. During the summertime the ladybird 
becomes more or less rare, no doubt due to the parasite effect- 
ively controlling it. 
The ladybirds seem to be of greater value in controlling 
Toxoptera in South Africa than in the case with the ladybirds 
which feed upon Toxoptera in the United States. The fact 
that Aphidius does not immediately destroy Toxoptera but 
allows it to live for a few days, during which time, if the Toxop- 
tera is an adult, it will produce young, detracts from the value 
of Aphidius, when compared with the ladybirds. An example 
will show better what is meant. Take a plant with 200 Aphids, 
50 adults and 150 young, under control conditions and introduce 
a female parasite. There is then a possible chance that all the 
Aphids on this plant will have an egg laid in them but this will 
not always happen, inasmuch as two or more eggs would be 
laid in one Toxoptera while others would escape the parasite. 
Granting, however, that all of them contained eggs and would 
