272 



Lange: Lepidoptera 



relationships of the various plants feeding Nymphuli- 

 nae. In general, however, the eggs are laid on the 

 under sides of the leaves of floating hydrophytes, 

 and the larvae cut out sections of leaves, often form- 

 ing cases in which they live. Oxygen requirements 

 are met by periodic vibratory movements of the larvae, 

 by cutaneous absorption, or by well-developed tra- 

 cheal gills. Pupation occurs in a silken cocoon inside 

 the larval case. The adults may emerge under water, 

 but do not usually enter water to deposit their eggs. 



Lloyd (1914) was apparently the first investigator 

 in this country to record the immature stages of one 

 of the Argyractini, Elophila fulicalis (Clemens) (now 

 in the genus Parargyractis), from swift waters in New 

 York, and little biological work has been done since 

 this time. 



The rock-dwelling forms are well represented in 

 the West. In the present study the larvae of four 

 species in the genus Parargyractis were found in 

 California. The larvae of a typical rock dweller 

 construct silken tents under which they feed on algae 

 and diatoms. Pupation occurs in dome-shaped, feltlike 

 cocoons, which have openings at each end to allow 

 the passage of water. The pupae are found in an 

 inner waterproof silken lining, and just before pupating 

 the larva cuts a semicircular escape slit for the adult 

 to escape from the tough cocoon. The adult females 

 enter the water, using the two hind pairs of legs as 

 oars, and deposit the eggs in groups on rocks, often 

 several feet under water in swift streams. The wings 

 of certain groups, such as the Parargyractis spp. are 

 held characteristically — the hind wings, particularly 

 in the males, are tilted at an angle downward from 

 the body. 



PARASITES 



Both tachinid and ichneumonid parasites have been 

 recorded from aquatic nymphuline moths. Lloyd (1919) 

 found about 50 per cent of the pupae of Elophila 

 fulicalis (Clemens) (Parargyractis) parasitized by an 

 aquatic tachinid, Ginglymyia acirostris Townes. 

 Ichneumonids in the genera Cryptus, Trichocryptus, 

 Cremastus, and N eostricklandia have been reported 

 from aquatic moths. 



I reared an ichneumonid near the genus P seuderip- 

 ternus, in the Cremastini, from the pupal case of a 

 Parargyractis sp., in Colusa County, California. 2 



PRESERVING AND COLLECTING 



Adults of the Nymphulinae can be collected at a light 

 often at some distance from water. Parargyractis 

 adults often rest upon the cement or wooden supports 

 of bridges over the streams they frequent and can be 

 collected during the day in such locations. They also 

 can be frequently swept from bushes or trees growing 

 along the edges of streams, and it is not unusual to 

 find them concentrating in certain trees back from 



^Determined by Miss L. M. Walkley. 



the water's edge. They frequent the shady and pro- 

 tected sides of large boulders along the edges of 

 streams, and can be flushed with an insect net. They 

 often occur with adult Trichoptera and frequent similar 

 locations. Adults of the plant-frequenting nymphulines 

 can be often collected during the daytime, resting on 

 aquatic plants. Toward evening they become more 

 active and can be collected as they fly from plant to 

 plant. 



Adults should be mounted and spread at the time 

 of collecting, but can be relaxed, in certain groups 

 at least, quite satisfactorily. Larvae can be dropped 

 into 70 per cent alcohol, but are best preserved by 

 killing first in hot water, then transferring to alcohol. 

 The rock-dwelling forms are collected in more oxygen- 

 ated niches in streams, lakes, or springs where the 

 larvae occur under silken sheets, or sometimes in 

 old cocoons. The cocoons are made of a tough, feltlike 

 material, and can be easily detached from the rocks 

 with a pair of forceps. It is difficult to rear adults 

 from detached cocoons, but those about ready to 

 emerge will do so in moist battery jars. Larvae or 

 cocoons should be left on rocks and placed in labora- 

 tory aquaria without disturbing them, if best results 

 are to be obtained. Larvae of the plants feeding forms 

 are usually taken in cases, either floating on the 

 surface or attached to the floating leaves or stems of 

 aquatic plants. They will often complete their life 

 history out of water, and adults will emerge from 

 pupae in cocoons if they are placed in moist rearing 

 chambers. 



TAXONOMIC CHARACTERS 



The wing venation, wing pattern and color, maxillary 

 and labial palpi, hairs and spines on the legs, the 

 antennae, sclerotized parts of the abdominal segments, 

 male sexual tufts on the abdomen, and the male and 

 female genitalia are all used in the classification of 

 this group of moths. Examination of the genital struc- 

 tures is necessary as color and patterns often vary. 

 The entire abdomen is usually removed and dropped 

 into 10 per cent KOH and heated for ten minutes to 

 several hours depending upon the age and individual 

 differences. It is well at the time of placing in KOH 

 to observe and record the color pattern of the abdomen 

 and the presence or absence of sexual tufts which 

 can be taxonomic characters. Under most conditions 

 the females will require a longer period of KOH treat- 

 ment than the males. Superficial hairs and extraneous 

 materials are teased out in distilled water. In the 

 females, the eggs and other internal structures can 

 be removed by slitting the sides of the body and 

 teasing them out so as to leave the genital structures. 

 The specimen is then transferred to a solution of 

 approximately 40 per cent glacial acetic acid, 30 per 

 cent 95 per cent alcohol, and 30 per cent water. After 

 fifteen minutes the specimen is transferred to cello- 

 solve to which has been added a few drops of clove 

 oil, left fifteen to twenty minutes, and mounted direct- 

 ly in euparol or balsam under a cover slip. In the male 

 the valva are usually spread apart, and the aedeagus 



