24 
at Tampico, would doubtless prove very injurious, at least to certain 
ornamental trees and plants, if introduced. It should also be remem- 
bered that Chionasj)is citri, Mytilaspis gloveri, and Aspidiotus ftcus have 
not reached California, but may do so through Mexico; just as Pseu- 
dococcus yuccWj which occurred in California, may reach the Southern 
States from Mexico. 
DANGER TO MEXICO FROM INTRODUCTIONS FROM OUR COUNTRY. 
There are a number of scales of the orange in California that are not 
yet known in Mexico. These could easily reach the Ilermosillo and 
Guaymas orange districts of Sonora by rail. Sonora, on the whole, 
probably stands in more danger from us than we do from her. 
Again, there are several bad species in our Southern States that have 
not yet reached Mexico, and which could easily do so on board steamers 
plying between New Orleans. Mobile, and Mexican ports. 
NATURAL ENEMIES OF SCALE INSECTS IN MEXICO DESIRABLE TO 
COLONIZE IN THE UNITED STATES. 
Among the Coleoptera, it would be very desirable to introduce 
Vedalia sieboldii var.. Ozyix orbigera^ and the species of Scymnm 
mentioned; nearly all of the parasitic hymenoptera (except Homalo- 
tylus) — about It species mentioned, of which probably but few occur 
within our limits — and the Phora cooeiphila bred from Icerya from 
Monterey and Victoria. 
AGENCIES NOT GENERALLY RECOGNIZED IN THE DISPERSION OF 
SCALE INSECTS. 
Tourists who visit Mexico often bring away with them specimens of 
live plants, etc. In this way they may play a greater part in the dis- 
persion of scale insects than do fruit shippers. Much is to be feared 
from this source, which is doubtless responsible for many introductions. 
It is more often practiced on steamers than on railroads. On the steam- 
ers which ply between different islands in the West Indies there are 
almost always to be seen potted and other plants which passengers are 
taking home with them from some other island. In this way it is believed 
by Professor Cockerell that many of the noxious scales found through- 
out the West Indies have been spread from one island to another. 
PORTS AND POINTS ON THE BORDER MOST TO BE GUARDED. 
The Pacific* ports of Mexico are supposed to be well guarded against 
by the horticultural inspectors in California, as already mentioned. The 
ports of our Southern States are open, at least during the colder season, 
to importations of injurious scales from the Gulf ports of Mexico and 
the West Indies. Inspection should be instituted of all plants, fruits, 
