PSYCHIDAE. By Dr. Eugen Wehrli. 
211 
22. Family: Psychidae. 
Not much is to be added to the exhaustive descriptions of this family given by Prof. Dr. Seitz m 
Vol. 2, p. 351 etc. and Vol. 14, p. 481 etc. 
Burrows has sought to solve the question of the inter-relationship of the Psychidae and the other 
lepidopteral families (and Phryganidae) chiefly by means of anatomical examinations and comparisons of the 
^ genitalia. His researches covered Phryganidae, Lymantriidae, Tineidae, Hepialidae, Limacodidae, Heterogynidae, 
Drepanidae and Zygaenidae. (The Entomologist’s Record, Vol. XXXVI, No. 6, 7 and 8.) He was not successful 
in establishing any closer relationship with the families named on anatomical grounds, but he assumes that, 
should a link be discovered, this will probably be with the nearest Tineidae. 
As already indicated in Vol. 14, according to recent observations also the larvae of the $ of most 
of the Psychidae turn round in the sac shortly before changing to a pupa. Thus the head would face the 
free aperture in a similar way to that described of the larva. In others however, as for instance m the 
Genus Gochliotheca, such an inversion of the larva does not as yet appear to have been observed. The imago 
emerges from the pupa case 'through an opening in the centre of the 2nd spiral of its sac, which is shaped 
like a spiral snail shell. The S pupal integument has often been found protruding from such opening after 
the emergence so that half the empty pupa is hanging out at the side of the sac and not from the extremity 
of same. From the position of such an integument of a $ pupa, the caudal extremity of which is directed in 
the sac towards the adhering end, it seems highly likely that the larva had turned round m the sac be oie 
pupation. In this Genus also therefore an inversion of the larva before pupation seems to occur. 
Jones has proved most convincingly by means of his very instructive illustrations and specimens, 
which he had prepared by a special method, that in an Acanthopsychidae, Thyridopteryx ephemeraeformis Haw. 
(Transact. Amer. Entomol. Soc. Vol. LIII, p. 293) and also in other species where the $? remain in the sac 
with their head towards the free end, with the pupal integument also in this position, that copulation actually 
thus takes place with the Its accordion-like abdomen penetrates deeply into the sac and into the pupal 
integument until it reaches the Ductus bursae. According to his observations a $_can pair with several Jp, 
a with 2 the $ then lays the eggs in the integument of the pupa by means of its ovipostor, a procec me, 
which some authors seem to dispute. This would appear however to be without justification. Only after the pupal 
integument has burst open (before pairing), the $ exercises attractive powers for the <$. 
Of the greatest possible interest in this family of the Psychidae, is the question of parthenogenesis. 
Since the publication of the 2nd Volume some important researches have been canned through and of these 
we must mention particularly the fundamentally thorough experiments and observations of Dr. Seiler. 
Unfortunately his premature death brought an abrupt end to his work. His labours were chiefly devoted 
to the socalled Micropsychidae, but they show remarkable analogies with species of the Psychidae group 
with which we are dealing heie and they especially enable us to understand better and realise the part len 
genetical biology of such species as Gochliotheca crenulella Brd v. helix Sieb. 
Seiler’s line of research started from his discovery of the fact that m Tahaepona tubulosa Rtzs. ) ne 
proportion in the numbers of $$ as compared with those of the $$, varied very considerably in ioca i res 
that were widely separated. He found for instance in Liegnitz a considerable preponderance of <J<J, 1 * • -■ o> 
at Wannsee the $$ outnumbered the 100 ? : 72 According to this, even allowing for an uneven 
infestation by parasites etc, the unequal proportion of the sexes cannot be due to mere chance and one ca 
assume that in the embryo state certain factors have exercised a deciding influence on the determination 
*) Archive for Cell Research 1920, Vol. XV, 3. Part, p. 249. 
