2fiO 



CECHENENA. By Dr. K. Jordan. — Hybrids of Sphingidae. By I)r. P. Denso. 



is shaded with black costally. Underside with a reddish tint ; costal margin of forewing light to the base, not 

 olive-brown like the cell; in the centre a brownish black transverse zigzag line: the olive-brown distal marginal 

 border produced basad in front of the middle, but this pointed projection does not reach the dark basal area. — 

 One pair from Siao-Lu in Western China, in coll. Charles Oberthtjr. 



43. Gomis: I'eelieiieiia R. <£• J. 



Differs from tlie preceding genus in the second segment of the palpus bearing very short scales and 

 therefore appearing much narrower than the first in a lateral view; moreover, the apical tuft on the inside of 

 segment 2 is small. — 6 species, which are all Oriental and of which 1 is met with in our Region. 



C. minor Butl. (= striata Roths.) (42 e). Greenish olive-brown, often yellowish ferruginous in places; 

 body with weak i)ut visible stripes. Thorax in contradistinction to lineosn Walk, without pale median stripe. 

 Forewing with 6 distinct lines and a submarginal indistinct one. and a black discocellular dot. Hindwing black, 

 the distal margin olivaceous, proximally to it a yellowish grey band which vanishes anteriorly. — Kno\\n 

 from Japan to North India, not yet recorded from Corea and Anuuland. 



Appendix. 



ll^bi*i<ls of* ^i|»liiiij;-i<lao. 



In nature hybrids between Sphingidae occur as a rule not very frequently, but nevertlieless a fair 

 number have been found at large either as larvae or as moths. Since a large number of the most diverse 

 hybrids have been bred in captivity, especially during the last few years, the moths caught in the wild 

 state have been examined more carefully and a systematic search for the caterpillars has been carried out 

 in districts which appeared to promise most succe.ss. It is essential for the occurrence of hybrids in nature 

 that two or more species fly at the same time on an area of very small extent. If under such circum- 

 stances the one species — A — appears rather earlier than another — B — , hybridisation takes place more easily, 

 at least as regards the species of Celerio and Pergesa, whose (J (J usually emerge from the chrysalis before the ??, 

 so that under normal conditions there are still virgin ?? of A when the first o,^ of B appear. There is thus 

 a greater chance for the latter of meeting $$ of A than of B, which favours the possibility of a crossing taking 

 place between B-cJ and A-?. This seems to occur, e. g., with Celerio hybr. epilobii Bdv., which is the product 

 of a cross Celerio vespertilio Esp. o X Celerio evphorbiae evphorbiae L. $. C. vespertilio emerges in nature 

 one or two weeks earlier than euphorbiae, and in both species the o o appear first, hybr. epilobii, it may be added, 

 has more frequently been found in nature than any other Sphingid hybrid. The inverse cross, hybr. densoi, 

 which is the hybrid A o X B ?, does not appear to have been observed with certainty in the wild state. Its 

 greater rarity is easily understood from the above explanation. 



In order to obtain hybrids in captivity it is advisable to proceed as folloM's: A sufficiently abundant 

 number of healthy pupae has to be obtained, preferably wild ones. These chrysalisses have to be kept during 

 the winter under conditions which approach as closely as possible the natural surroundings; in the spring, 

 however, the various species must be treated differently. It is essential that the species which one wishes to 

 cross emerge at the same time. In order to obtain this result it is not advisable to force the species which nor- 

 mallj' emerge late, but to retard the early species by lowering the temperature to a moderate extent. For 

 there is this danger in forcing that, though the moth emerge, their organs of reproduction are not yet fully 

 developed,^so that copulation would be without result. It is recommendable to entice by their own $9 the 

 wild 3,3 required for the cross. The moths ai'e placed in large cages, the Jo and $i of the same species being 

 kept apart in different cages. In these cages one should put every day fresh flowers such as are attractive for 

 Sphingidae (in the case of species of Celerio and Pergesa, being unnecessary with species of the Smerinthus- 

 group), such as Echium, Salvia, Silene, Lonicera, etc. One can even artificially improve the flowers by putting 



