CACTUS-FEEDENG INSECTS AND MITES 139 



greenii in South Africa, but also in the establishment of the "pest pears" 

 of the various countries. With reference to Australia, it is on record 

 that Governor Phillip, en route to Australia with the first colonists in 

 1 788, called at Brazil and took on board his vessel plants or joints of 

 prickly pear, and cochineal insects as well, for the specific purpose of 

 establishing a supply of the dye for military uniforms. The insect, 

 probably D. indicus Green, did not, however, become acclimatized in 

 Australia. 



FORMS RECOGNIZED 



There has always been confusion regarding the specific identity of 

 the cochineals, due to some of the following factors: 



The species are very similar in appearance; observations and 

 records in the field have very often not been substantiated by the 

 submission of material to specialists in the group. 



Morphologically the species offer few characters that facilitate 

 determination; in our experience, specialists have made erroneous 

 identifications. 



Each species possesses a wide range of Opuntia host plants; two species 

 may occur on the same host in the same region. Cochineal from various 

 sources in America became established in other countries, and their 

 origin was lost long before taxonomic entomologists described and 

 named them; thus D. indicus Green, described from India, D. ceylonicus 

 Green from Ceylon, and D. capensis Green from South Africa are all 

 now considered to be D. ceylonicus. 



Our own records are very imperfect. However, experience in the field, 

 combined with identifications made by various specialists, has gained 

 for us a knowledge of the probable identity of the cochineals occurring 

 in regions which have been given more than passing attention, viz., 

 the United States, Mexico, and Argentina. We recognize the following 

 forms: 



Dactylopius coccus Costa: the cochineal of commerce, naturalized 

 in many countries; native habitat probably Southern Mexico or 

 Central America; except for doubtful records from Peru, we have 

 not encountered this in the field. Host plants, Nopalea cochenillifera 

 and tree and semitree types of Opuntia, such as 0. ficus-indica, 0. strep- 

 tacantha relations, and 0. tomentosa. 



Dactylopius opuntiae Lichtenstein (the tomentosus (Lamarck) of 

 some authors): Texas to California and throughout Mexico; natural- 

 ised in Madagascar, India, Ceylon, and Australia. Host plants, many 

 species of Opuntia of shrub and tree-pear types. 



