SMERINTHUS OCELLATA. 441 



wrinklings, such as occur in the pupa of Mimas tiliae (Chapman). 



Variation in pupal period. — From August-September to 

 May-June may be looked upon as the normal period of pupal 

 life, but occasional individuals have only a pupal duration of three 

 or four weeks. On the other hand, occasional individuals remain 

 two years in the pupal stage before disclosing the imago, e.g., Todd 

 notes (E.M.M., vii., p. 61) the emergence of an imago in 1870 

 that passed a second winter in the pupal stage, the only one observed 

 out of hundreds of bred and dug pupae ; Lane records a $ bred 

 June 10th, 1900, from a larva taken at Brimsdown in 1898, and 

 Hill one bred May 29th from a larva taken at Hythe in 1898. 



Foodplants. — Salix, apple, plum (Linne), dwarf-sallow, 

 sallow, willow, apple (Hellins), almost all plants of the natural 

 order Rosaceae, also willow, sallow (Merrin), Populus nigra, Salix 

 caprea (Musham), Salix viminalis, Populus italic a, P. tre inula, Primus 

 spinosa, Pyrus communis, P. mains, birch, rarely (Bartel), Salix 

 triandra (Poulton), Cydonia vulgaris (Kroning), Primus padus 

 (Speyer), wild plum (Fenn;, Per ska vulgaris, Amygdalus com- 

 munis (Trimoulet), wild crab (Hewett), Salix repens (Atmore), 

 Populus alba (Harris), privet (James), bramble (Montgomery), 

 white aspen (Bouskell), Paradise stock (Pearson). The larvae 

 often commit considerable damage to the foliage of young 

 apple-trees, to which they are said often to transfer themselves from 

 Salix caprea; Horvath also notes them as injurious to the apple-trees 

 in Hungary. 



Parasites. — The larvae of S. ocellata appear very liable to 

 the attacks of ichneumons, some 75 per cent, of those obtained 

 on the Norfolk Broads being usually affected (Bacot). The larvae 

 are greatly affected by ichneumons in the London district, often 

 not 5 per cent, being free from their attacks ; it is easy to 

 detect those stung as the blue caudal horn becomes green and 

 has the appearance of the extreme tip having been bitten off 

 (Mera). Ambly teles palliatorius, Grav. (Marshall), Trogus lutorius, 

 Fab. (Fitch), Microplitis ocellatae, Bouche (-Microplitis ingrata, 

 Hal.) (the larvae of this species are gregarious, leave their 

 host in September, and form their greyish-brown rough cocoons 

 closely agglutinated together ; in these they remain until the 

 following May or June) (Bignell), Ichneumon pisorius, L. (Bouche). 

 [A very minute sand-fly, supposed to be a Simulium, attacks 

 the larva of Smerinthus planus in Japan. Pryer records (E.M.M., 

 xxiv., pp. 156-157) observing one (under the microscope), with 

 its proboscis buried in the back of a nearly full-fed larva. 

 Hodges records a brood of larvae of Smerinthus ocellata des- 

 troyed by wasps who cut each larva in two with the jaws, 

 carrying off the hind-part first and returning for the caudal 

 half.] 



Habits. — The imagines emerge in the early morning, never 

 later than 9.30 a.m. (Ransom) ; they then remain immovable until 

 8 p.m. or 9 p.m., when they suddenly, vibrate their wings and then 

 fly (Cowl). A pair of this species taken in copula, May 25th, 

 1892, remained paired until 7.45 p.m.; at that time the $ became 

 restless, vibrated his wings rapidly for some seconds, and appeared 

 to warn the ? that it was time to separate ; the ? , however, did 



