20 



them. By this method the trees may be almost entirely freed of the 

 Ked and the Black Scales, so that when the oranges and lemons are 

 gathered the following spring they will be practically tree of these pests. 



The Convex Scale. 



(Aspidiotus convexus Comst.) 



This scale appears to confine itself wholly to the bark of the trees it 

 attacks. I do not remember of a single instance where I have found it 

 infesting the leaves. Although usually attacking the Willow, on the 

 trunk of which it frequently occurs in immense numbers, still I have 

 also found it upon the Lombardy Poplar, Cottonwood, Walnut, and even 

 upon orange trees. By reference to my note book I find it stated that 

 on the 24th of April, 1890, I found a branch of an orange tree very 

 thickly infested with these scales. The branch at its thickest part 

 measured about 2£ inches in diameter and was covered with these scales 

 to a distance of about 4 feet on its basal or thickest part. 



This scale-insect is quite subject to the attacks of internal parasites, 

 although up to the present time I have known of only one species thus 

 to attack it. This is a small Chalcid fly known as Aphelinus fuscipennis 

 Howard. I have bred these parasites in June and July from scales col- 

 lected in the preceding April. 



If it is desired to destroy these scales this can doubtless be most read- 

 ily accomplished by the use of the resin wash referred to in the preced- 

 ing article. 



The Oleander Scale. 



(Aspidiotus nerii Bouch6.) 



This species, which appears to be pretty generally distributed all 

 over the known world, infests a great variety of plants. I have found 

 full-grown specimens on the following-named plants and trees: 



Oak (Quercus agrifolia). 

 Madrone (Arbutus menziesii). 

 Mghtshade (Solatium douglasii). 

 China Tree (Melia azedarach). 

 Lemon. 



Lilac (Syringa vulgaris). 



Arbor Yita3 (Thuja occidentalis), on 



the cones. 

 Century Plant, or Aloe (Agave 



americana). 

 Magnolia grandiflora. 



I do not find by my notes that I ever found these scales on citrus 

 trees of any kind, but I distinctly remember having found them upon 

 green lemons still hanging upon the trees, and my impression is that I 

 also found them upon the leaves of these trees. In the Annual Beport 

 of this Department for the year 1880, the Entomologist also records hav- 

 ing found these scales on lemons received from various sources (p. 302). 



In the above-mentioned report it is stated that the eggs of this spe- 

 cies are very light yellow in color, but I find by reference to my note 

 book that on the 14th of June, 1883, while examining an adult female 



