282 NOTODONTID^. Introduction. By Dr. A. Seitz. 



red tail-filaments, but is also able when excited to intensify the red colouring around the head, and, when 

 calming down, to weaken the red tint agaiii so much that it does not interfere with the green protective colour- 

 ing, a larva resting among leaves not being easy to find in spite of its odd shape. 



The role which the Prominents play in a fauna differs, of course, to a certain extent in the various re- 

 gions and countries, but is on the whole almost the same, every^vhere, as compared with other families. An 

 uinisually large number of genera is distributed over several continents, and certain types of Notodontids 

 are always met with and everyTvhere encountered almost daily. Whether one goes for a walk at Sydney in 

 Southern Australia or at Rio de Janeiro, in Japan or in Ceylon, in Lapland or Morocco, in New York, Vienna 

 or San Francisco, an examination of suitable shrubs will ever3rvvhere reveal without any difficulty jiuss-cater- 

 pillars which differ but little in fades from the larvae of our Dicranura and Cerura. A larva like that of our 

 Bufftip {Phahra), i. e. a hairy black caterpillar with light-yellow reticulation and which rests on a twig with 

 the fore and hind parts of the body raised, is found in Japan {Phalera dssimilis) and Turkestan, in the Hi- 

 malayas and on the Moluccas, in semitropical Florida {Datana modesta) and in wintery Canada [Datana per- 

 spimui), in the eternal spring of California and the sweltering heat of Morocco. 



The Notodontids are pre-eminently tree-insects. Their resemblance to pieces of bark, small splint- 

 ers of wood and broken-off tips of twigs already indicates that their food-plants must be looked for among 

 the deciduous trees. I do not know of any Prominent which feeds on conifers, the genus Thaumetopoea 

 being eliminated from the family; on the other hand, several genera (Ceira, Anticyra) are so well adapted to 

 bamboo that there remains little doubt about their feeding on these Monocotyledons. 



As regards the kind of landscape in wliich we may expect a large number of Notodonts, open country 

 interrupted by rows or groups of trees is decidedly the most favoured. The edges of woods and broad roads 

 crossing forests are known as suitable places for collecting Prominents, while the dark and damp interior 

 of young forests is frequented only by very few species. The plains are more favoured than mountains, and 

 in the entirely flat lowlands of eastern Europe and Northern Asia there occur not only numerous species, but 

 many of them are found in great abundance of mdividuals. The Notodontids are on the whole common Lepi- 

 doptera; very few of them are actual rarities, and it is quite erroneous to consider as very rare in Nature 

 the great number of Prominents which, like Pyg. timon and Drym. vittata, are rarely seen in collections. 

 Experienced collectors have assured me that by cuttiiag down likely young oaks in certain localities, on every 

 bush without exception at least one larva oi Stauropus fagi may be found, and that caterpillars as well as moths 

 as a rule are beyond reach of eye and hand. At Hongkong I observed bushes entirely denuded of foliage 

 by larvae of Stauropus, and the hungry caterpillars were seen running about far and wide in search of food. 

 Dozens of cocoons of Hoplitis milhauseri can often be gathered in avenues of oak in the crevices of the bark 

 if one has learnt to recognise the cocoon, which resembles a small hump of the bark itself. From experience 

 at home I was accustomed to consider Dicrarmra erminea as not plentiful until I found the wooden cocoons in 

 coxintless numbers one beside or on top of the other at the willows along a road near Shanghai, entirely fresh 

 moths just emerged of D. e. meiiciann sitting on some of the cocoons. In 1904 the Poplars at Lambessa in 

 Algeria were so much denuded by Dicran. delavoiei that not a single leaf remained and the trunks ap- 

 peared dotted with green from the larvae which crawled about and covered the grass and ground for a con- 

 siderable distance. The decimation by the Bufftip, Phalera bucephala, of the limes in the avenues of towns 

 is a very familiar experience, and it is likewise well-known how quickly Pygaera appears where a Poplar or 

 Willow is planted in a sheltered place. 



The Prominents are on the whole sluggish insects. One can jmt a pin through a Stauro pus-moth 

 at rest without in the least disturbing it. A Dicranura thrown into the air will fall down to the ground like 

 a piece of wood, and this may be repeated several times before the moth will issue to fly. I once put branches 

 on which freshly emerged Dicr. vinula were resting into a full water-trough; though half a yard below the 

 surface they kept clmgmg to the branch without awakening from their lethargic state, until want of breath 

 induced them after some minutes slowly to crawl upwards out of the water. Moths of Phalera and Datana when 

 handled keep the wings close to the body and can be rolled along the sandy ground without being induced 

 to move. Specimens of Pterostoma and Lophopteryx fall to the ground when touched, remain lying on their 

 side, and have even been observed to be attacked by ants in this state carried away some distance before show- 

 ing any sign of life. And the caterpillar behaves just like the moth; being mostly soft and flabby they 

 are slow and hesitating in their movements except when attacking. 



The caterpillars of many species are gregarious when young, while others are found singly. Young 

 Phalera bucephala larvae cover the underside of leaves, one specimen Ijing close to the other, and even when 

 full-grown they do not disperse far on account of their inherent sluggishness. The eggs of Dicr. vinula are 

 usually laid in pairs on leaves, and those of some Cerura quite singly. It is very remarkable how consistently 

 year after year some species are met witli in certain localities cc even on certain individual trees, while the 

 neighbourmg trees which offer apparently exactly the same conditions of life are avoided. I found, for in- 

 stance, for several years two trees of a group of Asps entirely denuded of leaves twice a year by the caterpillars 



