12 BRITISH BUTTERFLIES. 



CHAPTER V. 



OBTAINING EGGS OF BUTTERFLIES. 



The student of the eggs of butterflies, be he biologist, field-naturalist, 

 or photographer, will undoubtedly attempt to collect or otherwise 

 obtain the eggs required for study. The best modes of obtaining these 

 in confinement, and the best means of surmounting the difficulties that 

 occur, are, perhaps, rather out of place in a work of this kind, and have 

 already been dealt with fully elsewhere (Practical Hints for the Field 

 Lepidopterist). A few hints, however, as to the best methods of 

 obtaining the eggs of some of the species will, perhaps, not be so out 

 of place, especially as the systematic portion of this work will take 

 some considerable time in publication. The following hints are 

 arranged under the headings of the various months in a manner 

 likely to be followed by the field-naturalist, and in the order requiring 

 attention. 



January- April. — Eggs of Zephyrus quercus on oak, Thccla w-album, 

 on elm, T. pruni and Ruralis betulae on sloe, are all placed as a rule 

 near leaf-buds on twigs, and hatch towards the end of April. 



Eggs of Plebeius aegon (argus) pass the winter in this stage ; towards 

 the end of February a sharp eye should be kept on them, as they always 

 hatch in the last few days of February or the commencement of 

 March. 



Females of Polygonia c-album captured in late March and early 

 April will lay freely on hop, currant and nettle, if carefully sleeved on 

 plants that obtain a fair amount of sunshine. 



Hybernated Eugonia polychloros taken in the spring should be 

 retained for eggs ; both sexes should be sleeved together for the 

 purpose, as the earliest caught £ s after hybernation are rarely fertilised. 

 Sallow is one of the best plants for the purpose of sleeving, and if 

 the captives be fed with syrup, soaked into pieces of bark, they will 

 lay freely. 



When a 2 Gonepteryx rhamni is observed flying by a hedgeside or 

 on the outskirts of a wood, watch it until it selects a Rhamnus bush for 

 egglaying ; collect carefully the leaves and shoots afterwards ; you will 

 readily find the spindle-shaped eggs on the leaves and petioles. The 

 underside of a leaf, the twig itself, or a terminal bud, is usually chosen, 

 although the upperside of a leaf is not despised. 



At the end of April and in early May the eggs of Cyaniris argiolus 

 are laid singly on the underside of the calyx of holly-buds, so that, 

 when the flowers open, the sepals fold over the egg, hiding it altogether 

 from sight ; the eggstage lasts about ten days. The eggs are also laid 

 on the footstalks of flowers of Rhamnus frangula, and also on the young 

 leaves of ivy. 



May and June. — The pale greenish eggs of Nisoniades tages are laid 

 on the leaflets of Lotus cornicidatus from the end of May to the middle 

 of June, the eggstage lasting about a fortnight. 



females of Augiades sylvanus will lay their eggs in confinement in 

 late June, on cock's foot grass, if they be enclosed under a leno cover 

 and placed in the sun. Similarly, females of ( 'yclopidts palaemon may 

 be enclosed over a plant of Brachypodium sylvaticum. 



The circular, flattened, greenish-drab eggs of Polyommatus astrarche 



