258 



Distribution. — The extraordinary history of this destructive scale 

 should stand as a warning to horticulturists. Described by the Aus- 

 tralian Entomologist Try on in 1889, it is now known from Australia, 

 Ceylon, Hong Kong (Maskell, as geranii), Japan, California, district 

 of Columbia, Florida, Georgia, Jamaica, San Domingo, Grand Cayman 

 Barbados, Martinique, Trinidad, and Cape Colony. 



Food-plants. — It has come into prominence as a peach-scale in the 

 United States, but it has a great number of food-plants, including 

 peach, plum, geranium, grape, Guazuma, Cycas, Capsicum, Argyreia 

 Bryophyllum, Jasminum, cotton, Calotropis, Hibiscus, Zizyphus, mul- 

 berry, apricot, pear, Carica papaya, oleander, cherry, walnut, persim- 

 mon, Elaagnus, Callicarpa, Tylophora, &c. 



Destructiveness. — An extremely destructive species. In the United 

 States great trouble was experienced in dealing with it on peach trees. 

 In Cape Colony Mr. C. P. Lounsbury reports it as ' ' probably the most 

 destructive scale attacking deciduous fruit trees in the Colony ." (Eept. 

 of the Govt. Entomologist of the Cape of Good Hope for the year 

 1895, p. 48). Mr. Green records it as "very destructive to cultivated 

 geranium " in Ceylon. Although it was so recently discovered, quite 

 an extensive literature has appeared on this scale. It is hardly neces- 

 sary to repeat what has been written on the subject here, as full details 

 and excellent figures are easily accessible in the Annual Reports of the 

 U. S. Department of Agriculture for 1893 and 1894. 



Parasites. — For some time, no parasite of this scale was known, but 

 lately Mr L. 0. Howard has recorded the breeding of Aspidiotiphagus 

 citrinus from it in Ceylon. A parasite of the same genus — probably 

 the same species — has been bred from it by Mr. Lounsbury in Cape 

 Colony In Cape Colony it is attacked also by at least five species of 

 of lady-birds (Coccinellidce). 



Remarks. — Although D. amy gdali is the oldest name for this species, 

 it is much better known as D. lanatus, Morg. & Ckll. It was former- 

 ly considered that amygdali and lanatus were different species, but I 

 am convinced that they are the same, the supposed distinctions being 

 attributable to variation. Mr. Maskell is of the same opinion. 

 (59.) Diaspis cacti, Comst. (The Cactus Scale). 



Diagnosis. — Round greenish- white female scales with the exuviae 

 appearing as a dark brown spot. Male scales very small, linear, white, 

 with the yellowish or brown exuviae at one end. The var. opuntio?^ 

 Ckll., has the female scale with the exuviae not dark enough to con- 

 trast strongly with it. 



Distribution. — The var. opuntice is found in the Parade Garden, 

 Kingston, Jmaica. Another variety (opunticola, Newstead) occurs in 

 British Guiana. The typical form of the species is native in Arizona 

 and New Mexico, and has been introduced into hot-houses in other 

 parts of the United States ; it has also been lately reported from India 

 by Maskell. 



Food-plants. — Species of Opuntia, also Phyllocactus. 



Destructiveness. — It confines itself to cacti, but somtimes injures 

 the garden and hot-house sorts. Comstock says it was so abun- 

 dant in a conservatory at Ithaca, N. Y., that a large number of the 

 cactus-plants had to be thrown away. 



