388 INSECTS INJURIOUS TO THE ORANGE. 



often gather in great numbers on heaps of cotton-seed, when 

 they may be killed by pouring scalding water upon them. 



No. 248, The Orange Aphis. 



Siphonophora citrifolii Ashmead. 



In Florida this species of plant-louse is very prevalent, and 

 is found during the spring and summer months in various 

 stages of development, clustering on the tender shoots and 

 branches of the orange-tree. These lice insert their beaks 

 into the leaves and succulent twigs and live upon the sap. 

 When full grown, they are a little more than one-twentieth 

 of an inch long, black or brownish black, with plump, 

 round bodies, long, yellowish antennae, and pale-yellow legs. 

 (See Fig. 398, where they are shown magnified.) The winged 



Fia. 398. 



specimens, one of which is seen in the figure, are also black ; 

 these fly from one tree to another and establish new colonies. 

 Remedies. Syringe the trees with strong soap-suds or other 

 alkaline washes, or with strong tobacco-water. A number 

 of lady-birds and their larvse, also the larvse of Syrphus flies, 

 feed on these lice. Many of them are destroyed by a minute 

 Chalcid fly, which lives within their bodies. This friendly 

 species, Stenomesius aphidicola Ashmead, is shown, much 

 magnified, in Fig. 399, where a represents the female, and 6 

 the male. The short lines at the sides indicate their natural 

 size. They are so minute that as many as three of the perfect 

 winged flies have been known to issue from the body of a 

 single aphis. 



