16 BULLETIN 134, U. S. DEPARTMENT OF AGRICULTURE. 



If this scale occurred widely over the Valencia section in such 

 numbers as at Piaporto, Pic ana, and Piug, it would, of course, out- 

 rank the black scale in destructiveness. At the points mentioned 

 it is the most serious of all the scales because of its damage to the 

 tree, as well as its effect on the market value of the fruit. It occurs 

 also in injurious numbers farther south, as at Murcia, Malaga, and 

 Seville. It is very commonly seen on the fruit in the markets in 

 these sections, and the trees in many places show the effect of the 

 scales. Even in the famous Patio de los.Naranjos (Court of Oranges) 

 of the mosque at Cordova and of the cathedral at Seville the trees 

 are having a hard struggle to exist on account of the severe infesta- 

 tion by this scale. Taking the entire citrus area of Spain this scale 

 may be the most important, but in the important commercial section 

 of Valencia, where 90 per cent of the crop is produced, it is first only 

 in a few small areas. 



In the citrus belt along the French and Italian Riviera this species 

 was seen at San Remo and Porto Maurizio; at the former place in 

 destructive numbers on a few small trees. In Sicily it occurs at 

 Catania, Messina, and Palermo. (PI. Ill, fig. 4; PL IV, figs. 1 and 2.) 

 At Messina it is found in several places around the city and does 

 considerable injur} 7 . Its first recorded appearance on the island, 

 four or five years ago, was at this place. At Catania it is more or 

 less widely distributed, while at Palermo it is still limited to a few 

 small areas, but it is destructive as far as its spread has occurred. 



LIFE HISTORY AND HABITS. 



This species, somewhat like the yellow scale {Glirysomplialus 

 auraniii Mask., var. citrinus Coq.), attacks the leaves and fruit 

 largely. These will be found heavily infested and often there mil 

 be but a few on the twigs and branches. This habit of avoiding the 

 twigs and branches is not so complete as with, the yellow scale, but 

 is distinctly more pronounced than with the California red scale 

 (Clirysomplialus aurantii Mask.). In severe infestations, of course, 

 and where the leaves have fallen, C. dictyosperrni will be found in 

 considerable numbers on the twigs. Because the twigs and branches 

 are not so severely infested the injury is neither so great nor so rapid 

 as is the case with G. aurantii. But the dropping of the leaves 

 greatly injures the tree temporarily and new leaves scarcely grow 

 out until they in turn are attacked. 



While the life history of this species has not been worked out in 

 detail, it is probably very similar to that of C. aurantii. The latter 

 species requires two and one-half to four months for its develop- 

 ment. There would thus be between three and four, possibly four, 

 full generations in a year. 



