400 Introduction to Animal Morphology. 



wings, rudimental in the male ; tarsus two-jointed (one- 

 clawed in Dorthesia) ; females wingless, rounded, winged in 

 Aleurodes, their bodies covered with eggs ; the males have 

 a pupa stage in a cocoon ; Coccus cacti yields cochi- 

 neal ; C. lacca yields shellac ; Porphyrophora yields German 

 cochineal ; C. ceriferus yields Pe-lac wax. 2. Aphididae — 

 antennae five- (Chermes), six- (Rhizobius), or seven- (Aphis) 

 jointed, often longer than the body ; wings four, or none ; 

 tarsus two-jointed ; salivary glands and Malpighian tubes 

 none. Aphides, Lachnus, and Schizoneura have two glan- 

 dular cornula or honey tubes at the end of the abdomen, 

 the secretion of which is eagerly devoured by ants ; ocelli 

 none. Pseudoparthenogenesis occurs among these ; the 

 eggs hatched in spring, producing wingless, imperfect 

 females, whose ovary produces germs with no germinal 

 spot {pseudova), which develop without fertilization. This 

 process goes on in successive broods until the altered con- 

 dition of food and temperature at the incoming of autumn 

 checks it, and this last brood consists of males and females 

 with perfect sex-organs, whose fertilized eggs survive the 

 winter to undergo the same round on the renewal of favour- 

 able outer conditions. Schizoneura lanigera, with a red, 

 spotted abdomen, is a pest of fruit trees. 3. Psyllidse — 

 antennae as long as (Psylla), or shorter than, the body (Livia) ; 

 8-10 jointed, with two fine terminal aristae ; ocelli three ; 

 femur thick ; tarsus two-jointed, with lobes between the two 

 proper claws ; fore wings leathery. 4. Cicadellinidse — head 

 free ; frons broad : ocelli two, or none (Typhlocyba, found 

 on diseased potatoes) ; antennae short, two-jointed, aristate ; 

 fore wings leathery ; hind legs long. Aphrophora, with two 

 sharp calcaria on its hind leg, secretes the " cuckoo-spit." 

 Ledra has two upright, ear-like processes on the prothorax. 

 5. Membracidae — head down-directed, with two ocelli be- 

 tween the eyes ; prothorax with large processes, which often 

 overhang the abdomen, and whose shapes are often eccentric, 

 as stalked globules or ridges, &c. ; mostly American, except 

 Centrotus. 6. Fulgoridae : Lantern-flies — head with vesi- 

 cular or cornute processes ; wings colored. F. laternaria is 

 the lantern-fly of Guiana. Flata limbata produces Chinese 



