22 
Aguas Calientes. It was very bad at both piaces. These two loeali- 
ties are connected by deep and long barranecas, which run in & some- 
what northeasterly and southwesterly direction a little to the west of 
both places, and in which oranges are largely raised. Both localities, 
therefore, belong to the same region. Hither this or a similar variety, 
however, is known from Vera Cruz. 
Pseudococcus yucee is an exception, as it occurs from Morelos (State) 
to Guadalajara and Tampico, and is spread well over the plateau region, 
even extending into California. It is a much hardier insect. 
Aspidiotus scutiformis was originally found by Cockereli at Soledad, 
in the State of Vera Cruz, on leaves of a tree resembling avocado 
pear somewhat. Doubtless this tree is its native food-plant, or one of 
them, and this would indicate that the species had taken to orange and 
spread northward. This it could easily do, as there are no mountain 
ranges to act as barriers to its spread to the northward. The Gulf 
Coast region is a low, flat strip of country, from 50 to more than 100 
miles in width, between the Gulf and the foothills of the mountains, 
and running from southern Vera Cruz State to Texas, gradually widen- 
ing to the northward. Though this species was not met with at Tam- 
pico, if must occur in that vicinity, as it was found so abundant at 
Victoria and as far north as Monterey. It has so far been found only 
in the foothill regions of the eastern side on the Mexican table-land, 
in localities between 1,000 and 2,000 feet in elevation. It is very likely 
to turn up, however, at any time in Tampico and Matamoras. 
TIcerya purchasi is a more difficult case to explain, being found in 
Sonora on the west and in Tamaulipas and Nuevo Leon on the east. 
These two regions are separated not only by a vast tract of high table- 
land, but by the vast and almost unknown region of the Sierra Madre 
Mountains, and are totally unconnected by either railways or wagon 
roads, except in a roundabout way through the United States. It seems 
impossible that it should have spread from one region to the other, 
unless by means of cuttings sent from the Sonora region. It is more 
probable that it spread to the eastern region by cuttings brought from 
Jalifornia. 
SCALES THAT HAVE BEEN INTRODUCED INTO MEXICO FROM THE 
UNITED STATES. 
Turning now from the importation side of the question and looking at 
the exportation side, there is little doubt that Mexico has received sev- 
eral noxious species of scale insects from the United States through her 
steamship communication with the Southern States. Chionaspis citri, 
Mytilaspis gloveri, and A spidiotus ficus were found plentifully in Tampico 
and (except the first) in Brownsville and Matamoras, but not elsewhere, 
except that the last was found by Cockerell in Vera Cruz. They have 
doubtless been brought to these ports by steamers from Mobile and New 
Orleans. A. ficus is abundant in Jamaica, and may have been brought 
