1 76 Insects, 



height on that day, and was not disappointed. Ahout 11, A.M., they emerge from the 

 chiysalis, and ascend the trunks of the oaks; and from that time until half-past 4, P.M., 

 T captured forty-five males and eight females, notwithstanding that it rained inces- 

 santly all the time, accompanied with high wind, or I could have taken many more : 

 among them were some heautiful varieties. It is a great peculiarity ahout this insect, 

 its simultaneous appearance ; so that unless the collector is at the locality on that day, 

 his success is very doubtful afterwards, as hut few stragglers are seen ; what becomes 

 of them I cannot tell. On the same day, with similar weather, a friend of mine was 

 capturing Nyssia zonaria, so very local to Liverpool. This insect appeared in great 

 abundance ; to use his own words, " he could have captured five hundred specimens if 

 he had wanted them." They leave the chrysalis at the same hour as the preceding 

 species, but last much longer. Biston prodromarius, found also in Dunham park, was 

 at its height on the 5th of April, leaving the chrysalis from 2, P.M., till 6. Although 

 the park was well searched for some days afterwards, not a dozen specimens were ta- 

 ken, and those chiefly between the hours mentioned; thus proving the necessity of being 

 acquainted with their hours of appearance if we intend to be successful in their capture. 

 Larentia multistrigaria, Achatia piniperda, Anisopteryx leucophearia, and the true 

 female, a very difierent insect to the female of Anis. slictaria, so frequently placed in 

 cabinets for it ; — these, and some beautiful varieties of Diurnea fagella, quite black, 

 are the only insects worth recording that I have captured in this neighbourhood so far 

 this season. — Id. 



Note on the 'periodical occurrence of Colias Electra^ Linn. [C Edusa^ Steph.] I see 

 in the last 'Zoologist,' (Zool. 113) that the Rev. W. T. Bree has expressed surprise 

 that the remarkably fine weather which we had last year (1842) did not produce Colias 

 Electra as well as its congener, C. Hyale. Now, C. Hyale has been conjectured to 

 appear every seven years, (Entomol. 388) ; and from the experience that I have had 

 in catching C. Electra, which, in some seasons is a common insect on the cliffs in this 

 neighbourhood, it seems to recur plentifully every fourth year, though scattered spe- 

 cimens may sometimes be caught in the intervening time. If this be the case, they 

 will be found this year (1843), as they were very common in 1839. It is not, however, 

 the experience of a single person from a single place that can settle such a point, but 

 I was glad to see (Entomol. 385) that you mention their being found at the late Croy- 

 don canal in 1835, and again, Mr. Bree stating it to have occurred at Dover in 1831. 

 Both these dates agreeing with mine, seem to show that when it appears in one part of 

 the kingdom it appears in all : and I certainly think that if proper data were procured, 

 the recurrence of several insects, whose appearance is now supposed to be irregular, 

 might be predicted almost with certainty, as in the case of the Cicada septemdecim of 

 the United States. — Robert C. R. Jordan ; Teignmouth, April 18, 1843. 



Note on the periodical occurrence of Colias Electra. My own memoranda tend to 

 corroborate Mr. Jordan's views as to the appearance of Colias Electra in some abun- 

 dance every fourth year, and particularly in 1831, 35, and 39, in which years it ap- 

 peared simultaneously in many of the southern counties. This quadrennial appearance 

 occurs in some degree with other insects, for instance, the common cockchafer and the 

 goat moth ; but in both these instances the insect is supposed to be four years in ar- 

 riving at maturity, which can scarcely be the case with a butterfly. The occasional 

 appearance of insects during the intervening years, does not militate against the 

 quadrennial theory. — Edivard Neivman. 



Note on the remarkable abundance of hijbernating Butterflies. On Sunday last, 



