64 THE FLORIDA ENTOMOLOGIST 
duce, particularly in the case of winged females, hence a fair 
estimate of the average length of a generation probably will be 
nearly thirty days. In the laboratory, however, the average age 
of maturity was 12.6 days which is less than under natural 
conditions. Hence it is seen that the rate of reproduction for 
this aphid is much lower than for those previously described. 
This also accounts to some extent for their lack of abundance. 
Parasites. The most destructive parasite of this louse is the 
internal hymenopterous insect, Aphidius bifasciatus Ashm. This 
is a small wasp-like parasite but quite abundant, and the cause 
of killing many of the colonies. On several occasions one of these 
was observed ovipositing in the aphids. It would fly to the 
branch on which the aphids were feeding and approach cautiously 
until near the colony, then make a quick dart toward them and 
thrusting the abdomen between and under the legs, would quickly 
pierce the aphid with its ovipositor and run back. If undisturbed, 
it would repeat this practice several times. However, the ants 
which usually attend these aphids would often watch for this 
invader and drive him off before he reached the aphids. The 
parasite also appeared to be afraid of the ants. Another internal 
parasite of this louse is Aphidius pinaphidis Ashm. A few of 
these were bred from parasitized aphids, but they evidently are 
not as numerous as the other species. Pachyneuron micans How. 
was also bred from some parasitized bodies, but this may be a 
secondary parasite. 
Other enemies are the lady beetles, syrphus flies and aphis 
lions. Adults and larvae of Coccinella sanguinea were collected 
while feeding on the aphids. Syrphus fly larvae were often found 
feeding on the aphids and also Chrysopa oculata and Hemerobius 
sp. 
Ants. An interesting feature of Lachnus pini is the protection 
which the ants give them. Like all other plant lice the colonies 
are constantly attended by ants, and in this case several species 
of ants have been noted. They assist in spreading the species 
by carrying their young ones about and also protect them by 
driving away their parasites and predatory enemies. The most 
noticeable method of protection was a sort of cover built over 
them by the ants. The primary object of this probably was to 
keep parasites away but it would also serve as a protection 
against cold and storms. The ants were often observed during 
the fall and early winter carrying particles of loose bark aid the 
