10 
THE COLORADO EXPERIMENT STATION 
pruning- and picking of fruit serve, to some extent, to carry the movable 
ones from one tree to another. 
The effect of an infested orchard in infesting surrounding 
orchards is one of the most serious phases of the problem. On account 
of this scale spreading so slowly, it is noteworthy that well directed 
efforts of control are likely to be followed by quicker and more last¬ 
ing results than when orchardists wage warfare against more active 
insects. 
Howard scale parasite, Prospalta anrantii How., greatly enlarged. 
After L. O. Howard, Bur. of Ent., Washington, D. C. 
NATURAL ENEMIES. 
In a count made upon badly infested pear trees March 19, 1906, 
of a large number of scales, about 31 per cent contained no living 
insect. This did not, however, correctly represent the natural mortality 
of the insects due to weathering. Some of the dead scales resulted 
from parasitic or predatory insects. 
Early in June and again in the month of August adults of an 
interesting little bee parasite were observed. Specimens were deter¬ 
mined as Prospalta aurantu How., and the observation according to 
Dr. L. O. Howard is the first record of the parasite infesting "this 
insect. The minute bee develops within the body of the insect and 
eats a small round hole through the scale where it makes its escape. 
Dr. Howard reports that th's parasitic bee has been reared from San 
Jose scale and is effective against nine other species of scale insects 
common in different parts of the United States. A cut of the adult 
parasite is shown, greatly enlarged, in Fig. 1. 
Adult and larvae of a common lady beetle, Chilocorus bivulnerus, 
also played some part in the destruction of the scale. The beetles 
winter as adults and have been seen as early as February crawling 
over the bark performing their useful work. Adults of the beetle 
have shiny black outer wings each bearing a beautiful spot of red. 
The beetle in its various stages is shown in Fig 2. 
Last summer small spiders were observed destroying the newly 
hatched scale insects upon infested pear trees. Webs spun across the 
