VIII COCCIDAE SCALE-INSECTS 597 



the genus Margarodes, we can at present offer the reader no 

 satisfactory account.^ 



Products of Coccidae. — Honey-dew is secreted l^y Coccidae, 

 but as a rule not so extensively as by Aphidae and some other 

 Homoptera ; nevertheless, it is often sufficient to make the plants 

 frequented by Coccids very sticky and unclean. Some species 

 make a really extensive exudation of such matter. Eeaumur 

 records that a Coccid, which is doubtless Lecanium 2^c^'sieae, 

 excretes a supply of lioney-dew that drips to the ground ; he says 

 it tastes sweet and nice. The manna mentioned in the book of 

 Exodus is pretty certainly the honey-dew secreted by Coccus (now 

 Gossyparia) mmmifera, which lives on Tamarix in many places 

 in the Mediterranean basin. This substance is still called by the 

 Arabs " Man/' and is used as food ; in its natural state it is a 

 substance very like honey ; it is doubtless excreted by the 

 Coccus, and is not produced directly by the Tamarix as some 

 have supposed. Waxy matters are produced by several Coccidae. 

 Gero'plastes ceriferus, a Lecaniid, produces white wax in India. 

 Ceroplastcs is a widely distributed genus, and various species of it 

 have been used for the purpose of producing wax in other parts 

 of the world. The white wax of China is understood to be pro- 

 duced by another Lecaniid, Ericerus pekc ; but little is known as 

 to this Insect ; it is said that the wax is produced by the winged 

 males. The substance was formerly greatly prized in China, but 

 is falling into disuse on account of the introduction of Kerosene. 

 Lac is produced by Carteria lacca, a Lecaniid living in India on 

 Anona scpiamoscc, as well as on species of Ficus, Bhamniis and 

 other trees ; the lac is the shelly scale produced by the Insect 

 as a covering ; it is composed in larger part of resinous matter, 

 with which there is mixed a comparatively small c[uantity of wax 

 and other substances. The bo^ly of this Insect also affords the 

 red substance called lake. Various species of Kermes formerly 

 afforded a red dye well known to the Greeks and Eomans. These 

 Insects live on Quercus coccifera in the Mediterranean region. A 

 medicinal syrup is also obtained from them. Forphyrophora 

 polonica was used in North and Central Europe for the same pur- 

 poses as Kermes ; it is a Coccid living on the roots of Folygonum 

 cocciferum. These European Insects were replaced commercially 



^ For summary as to our present knowledge of this curious condition of Insect 

 life, see Mayet, Ann. Soc. cut. France, 1896, p. 419. 



