HYLES EUPHORBIA. 235 



Forcing pup^e. — This pupa lends itself readily to the forcing 

 process and imagines can thus be produced throughout the winter; 

 20 pupa? placed in incubator with evaporating' water, on January 

 10th, 1884, and subjected to a temperature fluctuating between 27°C 

 and 3o°C all emerged between January 28th and February 21st, 

 1884 (Weismann) ; three pupae placed in forcing-box October 21st, 

 1872, placed box at first on iron plate of a kitchen stove over 

 boiler where the situation was warm through the greater part of 

 the night and quite hot by day, when the bottom of the box was 

 elevated two inches above the hot plate by the aid of two strips 

 of wood on which the box rested ; here they were damped with 

 lukewarm water twice a day. On the 23rd of November a fine 

 and perfect moth came from the earliest pupa, but after that my 

 efforts were baffled \ the two remaining pupae continued lively but 

 the moths would not appear. I moved the box to a place before 

 my sitting-room fire, but without effect, and, at last, I came to the 

 conclusion that I ought not to have begun the forcing till the weather 

 had become dry and frosty, and that then the heat would have had 

 due effect, but as it was, the great humidity of the atmosphere had 

 prevented this, and sufficient heat had not reached the pupae to 

 develop the imago in them at once. After continuing my forcing 

 till the end of December, I put the pupae aside to wait for summer, 

 but before that time came they had died (Buckler). We have 

 more than once placed pupae of this species on moss in flower-pots 

 on a kitchen mantel-piece in January and moistened the moss 

 slightly every day ; few of the pupae resist this treatment more than 

 5-6 weeks before giving up their imagines. 



Foodplants. — Euphorbia, \GaliunPf (Linne), Euphorbia cyparissias 

 (John), E. amygdaloides (A. H. Jones), Euphorbia peplus, E.portlandica 

 (Buckler), E. paralias (Harrison), E. esula (Glitz), Tithymalus 

 helioscopius, T. gerardiana, Fuchsia (Bar Lei), E. piscatoria (Long- 

 staff), E. guyoniana (Eaton), E. dendroides, E. pinea (Galvagni), 

 E. wulfenii (Garbowski), Euphorbia exigua, preferring slightly 

 withered leaves (Sich), particularly fond of the milky juice of the 

 Euphorbia (White), vine leaves (Berthelin, Buli. Soc. Ent. Er., 1881, 

 p. clvii), [oak (Scheffler)]. There is some suggestion of " gastric educa- 

 tion" in the species, e.g., Garbowski notes larvae as eating Euphorbia 

 cyparissias but refusing E. peplus and other Euphorbiaceae. Robson 

 records (Young Nat., ii., p. 310) E. peplus being preferred to E. 

 amygdaloides and E. esula. He adds (teste Millar) that the larvae 

 will eat dandelion, on which, however, they do not thrive. Unterberger 

 fed the larvae on lettuce (III. Zeits.filr Ent., hi., p. 232). Laubenheimer 

 has (Ber. Oberhess. Ges., vi., p. 82 [1857] ) a short note on the foodplant 

 of this species which, he says, is rare at Giessen on account of the 

 absence of its natural foodplant, although occasional larvae have been 

 met with on the species of Euphorbia growing in the Botanical Gardens. 

 He asserts that no other foodplants but species of Euphorbia are known, 

 and Esper has expressly mentioned that he repeatedly tried to induce 

 them to take substitutes, but failed; Laubenheimer thinks it, 



* Linne's references (see antea, p. 202) show that he had mixed up euphorbiae 

 and gallii under the former name. Undoubtedly this foodplant " Galium " resulted 

 from referring De Geer's species {gallii) to euphorbiae. 



