2 



HOMOPTERA 



Cockerell (i) catalogued the species of the world accoiding to their geographical distribution, and 

 proposed subgenera Dialenrodiciis for Alenrodiais, with A. cockerelli, Quaintance as type; and for 

 Aleyrodes, subgenera Asterockiton, Dialeurodes. Trialairodcs and Tetraleurodes. with AUyrodes aureus. Maskell- 

 A. citri, Riley and Howard ; A. pergajidei, Ouaintance: and A. perileuca, Cockerell as types respectively. 

 A valuable paper by Peal (2) was published in igo3 on the known Oriental species of the family in 

 which 16 forms are listed for tlmt region, seven being described as new. The Aleyrodids of California 

 were treated in 1904 by Florence ]£. Bemis (3). with references toother American species. In the paper 

 cited, 23 species are recorded for the Stale, ly of which were described as new. 



In 1907, a catalogue of the species of the world, hy (,',. W . Kirkald}-, was published, with descrip- 

 tions of six new species b}' Jacob Kotinsky (4). Also in 1907, Albert Tullgren established a new genus, 

 Ahiirochitou, with Aleyrodes aceris Geoffroy as type, presenting also detailed descriptions of Aleyrodes pro- 

 leiella Linné; A. brassicae, Walker; A. fragariae, Walker and Aletirochiton aceris, Geoffroy (5). 



The specific characters in Aleyrodes are determined mainly from the so-called a pupa case », the 

 adults in this genus being remarkably similar in structure and coloration except those species with 

 spotted or banded wings. In Aleui odiciis. tin- ailults are likely to vary more but in this genus also the 

 pupa case offers good diagnostic characic is. In < hai acterizing species of this family, descriptions should 

 be made of as many stages as possible, as the egg, pupa case, and adults. Certain species may be sepa- 

 rated with certainty only after a comparison of all these stages. Man}- descriptions, especially of the older 

 writers, are too incomplete to permit of the positive identification of their species. 



To any one who has given even casual attention to this famil}-, it will at once be evident that the 

 present list of species for the world represents but a small fraction of those which exist. It is hoped that 

 entomologists, especially those in tropical and sub-tropical parts of the world will interest themselves in 

 this ver}' interesting family. 



Directions for collecting. — In collecting specimens of Alexrodidae, special attention should 

 be given to securing adult as well as immature stages. If leaves infested with pupa- be placed in suitable 

 jars fora few days, adults may often thus be secured. Frequently adults ma} be found in abundance on 

 the more tender growth of plants infested by the immature stages. After necessary live notes as to 

 color, etc., have been made, abundant specimens should be preserved in thin xylol balsam mounts on 

 slides. It is often necessary to boil in KOFI 3 the darker larvae and pupa cases, before mounting, to render 

 their structure discernible, as in the case of coccids. I,eaves infested with immature stages also should 

 be preserved in a way to keep intact the waxy secretion, often of much importance in making prelimi- 

 nary determinations. Adults may be preserved dry in suitable vials and held in place with bits of cotton, 

 or mounted on « points » as is done in the case ot various minute insects. 



Economic species. — But few species of this family rank as serious pests, but the injuries of 

 some are quite important. Aleyrodes citri, Riley and Howard, is perhaps the principal pest of the orange 

 at the present time in Florida, and has been lately introduced into California, This species has been 

 well treated by Riley and Howard (6) and by H. A. Gossard (7). Aleyrodes bergii. Signoret, A. lacteae, 

 Zehntner and A. longicornis, Zehntner are all destructive to sugar cane in Java, and have been carefully 



(i; The Classification of tlie Alei<ro,ii.iae (Proc. Acad. Nat. Sc. Philad. Vol. 54. p. 279-283 (iqoz). 



(2) Contributions toward a llonograpli of the oriental Aleuroduiae (Journ. Asiat. Soc. Bengal, Vol. 62, p, tii-08 (iQoj), 



(3) The Aleyrodids or mealy-xMnged flies of California (Proc. U. S. Nat. Mus. \o\. 27, p. 471-537 (rgoé . 



(4) A catalogue of the Hemipterous family Aleyrodidae and Aleyrodidae of Hawaii (Bull. 2, Div. of Ent. Board of Com. of Agric. and Forestry 

 of Territory of Hawaii (1907). 



(5) Ueber einige Arten der Familie Alfurodidae. Arkiv. for Zoologi, Stockholm, Bd. 3, N* 26 (1907 , 



(6) Insect Life. Vol. 5, p. 219-326 (1893). 



i7) Bull. 67, Florida Agric. Exper. Station (1903). 



