1960 Journal of the Lepidopterists' Society 37
STUDIES OF THE CHROMOSOMES OF NORTH AMERICAN RHOPALOCERA 2. HESPERIlDlE, MEGATHYMIDlE, AND PIERIDlE
by KODO MAEKI and CHARLES L. REMINGTON
The first of this series of papers was on eleven species of Papilionid~ and included an introduction and a description of the sources of our material and of the techniques we use (Maeki & Remington, 1960). The present paper is a continuation of the first and covers species of the two families of the super family Hesperioidea and the family Pierid~. The remaining families are be ing covered in two papers immediately following this one. The numbers in squa re brackets are the designations of individuals studied and can be found on the specimens and slides preserved for permanent reference in the Peabody M l1~eum of Yale University. In the following lists" n" represents the hap loid chromosome number, "I" refers to the primary spermatocyte division and "II" to the secondary spermatocyte division. No female meiosis was investi gated in these three families. Most of the specimens for which the chromosomes are reported here were taken in 1959, the principal exception being the interesting genus Erynnis. We extracted om 1960 K'rynnis data and inserted it as the manuscript was going to press. Counts for many additional species of Papilionid~, Pierid~, and Hesperiid~ are being made from 1960 material and will be published in a supplementary paper. We have also worked up about two dozen species of African Rhopalocera collected by S. A HESSEL in 1960, including 7 Pierid~ . Thes(' are being reported separately from the present North American series, \V (' found no meiotic divisions in males of the following species: two OarislI1a garita (Reakirt), three Polites draco (Edwards), one H esperia (colorado Scudder?), and one Pyrgus communis (Grote) from Colorado; on(' Ancyloxipha nUll7itor (Fabricius), and one H esperia leonardus (Harris) from Connecticut; fourteen Erynnis brizo somnliS (Lintner) from Florida; one lHegathYll1us y. YllCCCF (Boisduval & Leconte) from Georgia; and two A gat hYlllus estel/ea: (Stallings & Turner) from Mexico. H esperioids in gen eral tend to have meiosis completed before or soon after eclosion, and it is necessary with some species to try several young males or even pup~ to get suitable divisions.
A HESPERIID.& : 1. A chalarlls loxeliS (Pl
••• •• • •• •••• • •••••• ••• •••••, •••••••• • • •••• .. .. lb lc • la •••
••• • ••• • •• •• •• • •• • •• •••••••• •••••••• ••• ••••••• ... -. • • ••• • • •• • • •• ••••••••• • • ••• 2 •• • 3b • •• 3a • ••••
•• • • ... • -. • •• • •••• •• :• ...... ••••• • •••• ••••• • ••• • • •••• • •••• ••• • • • :••• • •••• •• • •... •• 4a ••• 4b 5 e.· ••••••••••• .• . •. • :. ...- .-. .. . .- .. ••• ••••: .- .... :.. 7a ••• .•••••. .... • .••••••••••...... •• ••••••• ••• ::.:: . ••••• • •• 6b 6a ••••./. .. ••••••• • 7b ••••
Fig. 1a - //rhalarlls foxeus (I); fig. 1b - ,arne (II; n = 16) ; fig. 1c - same (II; n = 17); fig. 2 - Chioides wlillus (I); fig. 3a - OeModes syi'lJanoides (I); fig. 3b - same (II); fig. 4a - Nastra /'herminieri (I); fig. 4b - same (II); fig. S - M I'gathymus 'lJiolce (II); fig. 6a - Stallingsia maw/osa (I); fig. 6b - same (II); fig. 7a - // gathymlls mari(/! (I); fig. 7b - same (II). [On plates 1-5: I = primary spermatocyte division, II = secondary spermatocyte division; magnifications all 3900 diameters; drawings made with camera lucida.]
39 40 MAEKI & REMINGTON: Chromosomes Vo1.14: flo.1
8. Erynnis luciLius (Scudder & Burgess). N = 31. Counts were made in testes of 2 males reared from larvie taken on A quilegia canadensis all Rat tlesnake Mt., Hartford Co., Connecticut, in June 1960 by R. W. PEASE, JR., and W. A. CHRISTIAN. These emerged in late June and July, and the testes were fixed soon after eclosion. Counts of 31 were invariably obtained for male 617 in 15 nuclei (I) and 10 nuclei (II), and many other suitable nuclei could have been counted. There are 4 small, 11 large, and 16 intermediate chromosomes. Male 836 was apparently a wild hybrid, since the 21 countable metaphase nuclei (all 1st spermatocyte) showed the following chromosomal tally:
chromosome no. (n) 32 33 34 35 36 37 number of nuclei 4 4 2 3 5 3 apparent univalents (extra tiny elements) 2 4 6 8 10 12
This suggests that the other parent of the hybrid was a 31-chromosome species, and distributional facts point to E. baptisice. Probably the female parent was K lucilius, since the egg was laid on the lucilius food plant. The few second ary sperrnatocytes were not satisfactory for counting. 9. Grais stigmaticus (Mabille). N = 31. Counts were made in 37 nuclei (I) and 22 (11), in the testes of 2 males [M23-6, M23-7J taken at Ciudad Victoria on 1 August. Of 11 males whose testes were fixed, meiotic divisions were found only in these 2. Most of the specimens were collected at muddy spots in a river bed. There is some diversity in the sizes of the chrom osomes, with about 8 being smaller than the others. 10. Ochlodes sylvanoides (Boisduval). N = 29. Counts were made in 17 nuclei (T) and 14 nuclei (II), in the testes of 2 males [275, 276 J taken near Somerset, Gunnison Co., Colorado, on 15 August 1959. No meiotic di visions were found in the testes of 6 other males taken at the same time. Es pecially in the secondary spermatocyte 2 of the chromosomes are much larger than the other 27, suggesting 1 + 1 fusions of 4 of 31 ancestral chromosomes. 11. Nastra l'herminieri (Latreille). N = 30. Counts were made in 12 nuclei (I) and 5 nuclei (II), all in a single male [329J taken on West Rock, New Haven, Connecticut, on 5 September 1959. It was clearly observed that 5 of the chromosomes in the primary spermatocytes are about one-half as large as the other 25. The few secondary nuclei were somewhat oblique in our sections, and size differences could not be safely estimated.
B. MEGATHYMIDlE: 1. Megathymus violce Stallings & Turner. N = 27. Counts were made in 5 nuclei (II) in a single male [417 J reared at Yale from an egg collected 29 July 1959 at 4000' on Yucca treculeana on the highway pass over the Sierra de la Gavia, Co.ahuila, Mexico. The testes were fixed immediately af- CHROMOSOMES PLATE 2
••• .. ~ . • •• .•••...... • • . · .:.. • ••••••• ••••• •••• • • •••••••• •• • ••• • •..... •••• • •••• 8a ••• . 9a ••• lOa • •••
...... •• • •• ••• .•...•• •••• : . •••••• · -.. a.a •••• :_ : .:.:-: . • •••••••• -.:.:.: . 8b • •• 9b ·~ .. lOb ••
• •••• • ••• ·.. -.. . •••••• • ...... -.. . •. •••••: .... • •• • • • • • •• • •••• lla • • 12a • ••• • ••••• ••••••• • • •• •••••• . :• .....• ... -.. 13 ••• •• • ••• . .... : .. .. : ... • •••••• ••• 11 b •••••• • • 12b • • •
• ••• •• ••• • ._ •... •• • • •••• • •• ••••• ••• ••• • • ••• •• • •• 14b •••• 14a • ••• •
Fig. 8a - Erynnis icelus (I); fig. 8b - same (II); fig. 9a - E. jU'lJenalis (I); fig. 9b - same (II); fig. lOa - E. horatius (I); fig. lOb -- same (II); fig. lla - E. persius (I); fig. llb - same (II); fig. l2a - E. baptisid! (1); fig. l2b - same (II) ; fig. 13 - E. lueilius (I) ; fig. l4a - Grais stigmaticus (I); fig. l4b - same (II).
41 +2 lYfAEKI & REMINGTON: Chromosomes Vo1.14: n[J.l ter eclosion the morning of 31 December 1949, and fortunately there were still a few divid ing cells, none at the first division. All the chromosomes are similar in size. 2. Stallingsia macu/osa (H. A. Freeman). N = 50. Counts were made in 23 nuclei (II) in testes of a pupa [424] ready to hatch and 22 nuclei (I) and 46 (11) in testes of a very young pupa [425]. Both were dissected OIl 2 April 1960. They had recently been collected as mature larv::e by DON B. STALLINGS at Floresville, Wilson Co., Texas. One of the chromosomes is much larger than the other 49. 3. d gathYlIllls I/larid~ (Barnes & Benjamin). N = 21. Counts were made in 5 nuclei (T) and 4 nuclei (II) all from a single newly hatched male [398J which emerged 28 September 1959 and had been collected as a blue larva in early August, 5 V2 miles east of Langtry. Val Verde Co., Texas. in Agava /echegl1illa Torrey by C. L. REMINGTON. Two chromosomes are larger than the other 19.
C. PTERID1E: I. K"l1chloe allSOllidl's Lucas. N = 31. Counts were made in 17 nuclei (1) and 6 nuclei (II). all from a single male [45-1] taken at Gothic, Gun nison Co., Colorado, 19 .T uly 1959. No dividing cells were found in the testes of a second male taken at the same place. All the chromosomes are similar in SIze. 2. CoZias eurythelile Boisduval. N = 31. Counts were made in 53 nuclei (T), and 34 nuclei (TJ), in testes of 4 males [316-1, 316-a. 316-b, 354 J taken in New Haven Co., Connecticut, 3 and 11 Sept. 1959. Then> are 7 large. 19 medium-sized, and 5 small chromosomes. 3. Colias philodin' Godart. N ,- 31. Counts were made in 74 nuclei (I) and 62 (If), from 9 males taken in New Haven Co. from 3 to 19 Sept. 1959 [315-1, 315-2, 315-3, 315-4, 315-6, 315-7, 330, 352, 382]. About 7 or 8 chromosomes are larger than the others. Wild hybrids of C. philodice X l'urythclI/(' were also studied and showed no failure of pairing at first meiotic metaphase; thest' are being reported elsewhere in a separate paper on cytology of wild hybrids. +. Colias alexandra Edwards. N = 31. Counts were made in 58 nllclei (I) and 17 nuclei (II) from testes of 3 males [82, 154, 162J taken at Gothic from 22 to 30 .T uly 1959; testes of a fourth male showed no meiotic divisions. Several of tht' chromosomes are more or less larger than the others. S. Colias scudderii Reakirt. N = 31. Counts were made in 40 nuclei (I) and 22 nuclei (II) from testes of 6 males [3, 17, 19,29,129, 131] taken at Gothic from 17 to 27 Julv 1959. There are.5 or 6 chromosomes which are larger than the others. Wild hybrids of C. sCl1dderi X alexandra showed some failure of meiotic pairing: a, with C. philodice X curytheme thl'se studies are being reportt' d elsewhere. CHROMOSOMES PLATE 3
• •• • ••• • ••• • •• • • •••• • • • ••••• • • • ••• • ••••• ... : ... ••••• -. -.-.-•• •••••••••• • • ••••• •• ••• • • •• •••• ••• • •• •• ·••- •• .. •• • •• .- ... • • •• 16b 15a • • 15b 16a
• ••• •• • ••• ••• • • • •••• • ••••• • ••••• .-...• • • • •••••• • • •••••• • •••••• •••• •• • ••••• • ••••• • •••• ••• •• e•••••• -...... •• ••••• • . • 18b 17b 18a • •• 17a •••
••• ••• • • • • • •••••• • ... - •••••• • •••••••• •••••• •• ••- • • •••••• ••• • •• ••• ••••• •• •• •·•• ••• • • •• • ••• •••• •••••• .. :.. : • •• •• • • • • ••• 20b 19a •• 19b •• 20a
••• • • • •• ••• . ... -. • •••••• ••• ••••• • •• •••• • • ••• • ••• • e ••••• • _ 21a •• •• • 21b
Fig. 15" - Euchloe ausunides (1); fi g. t 5b - same (II); fig. 16 a - Colias fury/hf'II/(' (I); fig. 16b - sa me ( II); fig. 17a - C. phiiodice (I); fig. 17b - same (II); f ig. IS" - C. alexandra (T); fig. 18b - same (II) ; fig. 19a - C. scudderii (1 ) ; fig. 19b - same (II) ; fi g. 20a - C. meadii (I); fig. 20b - same (II); fig. 21 a -- '/rrfl1r amnia (I) ; fig. 2lb - same (II).
43 44 MAEKI & REMINGTON: Chromosomes Vo1.14: no.1
6. Colias meadii Edwards. N=31. Counts were made in 15 nuclei (I) and 12 nuclei (II) from 3 males [189, 216, 218J taken in Gunnison Co., Colorado, found at Copper Lake, el. 10,500', on 2 August, and Cumberland Pass, el. 11,500', on 11 August 1959. As with other high altitude butterflies, dividing cells and also germ cells were few in number. About 7 or 8 chromo somes are large, 4 or 5 small, and the remainder medium-sized. 7. Zerene cesonia (Stoll). N = 31. Counts were made in 26 nuclei (I) and 23 nuclei (II) all in the testes of a single male [M7J taken at Ciu dad Victoria, 1 August 1959. About 15 chromosomes are somewhat larger than the others. 8. A nteos clorinde (Godart). N = 31. Counts were made in 41 nuclei (I) and 46 nuclei (II) in testes of 5 males [M6-1, M6-3, M6-4, M6-5, M6-6] taken at Ciudad Victoria, 1 and 2 August 1959. There is some diver sity of chromosome size. 9. Phcehis philea (Johansson). N = 31. Counts were made in 53 nuc lei (I) and 39 nuclei (II) in testes of 7 males [M5-1, M5-2, M5-3, M5-4, M5-5, M5-6, M5-7], taken at Ciudad Victoria, 1 and 2 August 1959. There is some diversity of chromosome size. 10. Kricogonia lyside (Godart). N = 31. Counts were made in 81 nuclei (I) and 58 nuclei (II) in testes of 7 males [M28-1, M28-2, M28-3, M28-4, M42-1, M42-2, M42-3J taken at Ciudad Victoria, 1 and 2 August 1959. The chromosomes are all similar in size. Assuming that two species, K. lyside and K. castalia (Fabricius), were present at Ciudad Victoria, we had separated two groups of males and their fixed testes. It is believed by present taxonomists that these two "species" represent only one. The chromo somes being indistinguishable in our two groups, we can offer no cytological test of the species question in Kricogonia. It is possible, of course, that most closely related but discrete species show no conspicuous chromosomal differ ences. 11. Eurema proterpia (Fabricius). N = 31. Counts were made in 30 nuclei (I) and 32 nuclei (II) in testes of 2 males [M31-1, M31-2] taken at Ciudad Victoria, 2 August 1959. As with other Eurema, there is little size difference among the chromosomes. 12. Eurema mexicana (BoisduvaI) or E. hoisduvaliana Felder & Fel der. N = 31. Counts were made in 24 nuclei (1) and 33 nuclei (II) in testes of one male [M37-2] taken 2 August at Ciudad Victoria. In contrast to l E. lisa, meiotic divisions were very numerous and the testes much larger. Un ; fortunately, in one vial testes were fixed together of two males which appeared J in the field to be of the same species. When Dr. A. B. KLOTS checked the specimens, one proved to be E. hoisduvaliana and the other E. mexicana, but meiotic divisions were present in testes of only one of the specimens and there is no way of knowing which. It is highly probable that both species have a haploid number of 31 since all 4 North American species studied by us show CHROMOSOMES PLATE 4
•• • e •••• ••••• " . ••• • . .-.: .. -" ' .' .. ••••• • •• ••••• ...... " .~. ••••• • • • ••••• .• ••••• ••••••••• • .... -. •. •••..... 22b "1 22a .•• " e .' .. . 23b 23a .. '
., . '.'. '. .;.-.:.." • •••• ••••.' · . •••••• ' .. • ••••• • ~ • ' ••• e. • .. -:.: • • .. .. ••••• • ....e ••• :.. .' .. ~ " .. ' .'" ... ' . 24b • • • 25b .' .. 24a · .. 25a • •
' .. .' • ., . •• • • •••• .'.. .. • •••••• '.'" • •••• ••• .- ., .. • •••• •· ".. ••• ..... '- .'' .... .:'.. • • I, ••~ .. • •• •••• ••• I ••• • ••••• . .. ' 27a •• ' 27b 26b 26a ' .. '
••• ' '. '.' .' ..... ••• ' ••••. • • •••••, • •••••• •••••• .- ... ~ ...... ••••••• , e••• .. .. - .." . ' . -.. - " . 28 . . 29a .-' 29b Fig. 22a - Auteos clorinde (I); fig. 22b - same (II) ; fig. 23a - Phcebis philea (I) ; fig. 23b - same (II); fig. 24a - Kricogouia lyside (I); fig. 24b - same (II); fig. 25a - Eurema proterpia (I); fig. 25b - same (II); fig. 26a - E. mexicaua or boisdu'Valiana (I); fig. 26b - same (II) ; fig. 27a - E. uicippe (I); fig. 27b - same (II) ; fig. 28 - E. lisa (I); fig. 29a - A ppias drusilla (I); fig. 29b - same (II).
45 40 MAEK[ & REMI»;GTO!\: Chromosomes \'01.14: llo.l
this Ilumber; however the two knowll Japanese species show 11 = 29 and 1/ = 31, respectively, and it will be essential to check the present case with un qurstionably corre!atrd specimrlls and testes. 13. FlIrl'l/la nicippc (Cramer). N ,= 31. Counts were made in 6 nuclei (I) and 15 nuclei (II) in tf'stes of 2 males [l\IR- l, :\IR-2l taken at Ciudad Victoria, 1 August] 959. 1-1-. FlIrcllla lisa (Boisduval & Leconte). N ,= 31. Counts were madt' ill]9 nuclei (l), in testes from 2 males [31-1--A, 3H-B] taken at West Rock. Ne~,· Haven Co., COllllrcticut, 3 Sept. 1959. The gonads were small and had few dividing cells, 110ne in the secondary division. 15. A ppias drllsi/la (Cramer). l\' = 32, Counts were made in lO2 nuclei (l) and 76 nuclri (If) in testes of 6 males [:\143-1, l\I-I-3-2, M43-3, :\143--1-, :\1-1-3-5, M43-6J taken at Ciudad Victoria, 2 August 1949, All thr chromosomes are similar in size. 16. Pieris napi lI1flCdllllllOlighii Remington. N= 25. Counts were madt' ill 18 l1uclei (I) and 8 nuclei (11) in testes of 3 males [14, 15, 16J taken at Gothic. Colorado, 17 July 1959. All the chromosomes are similar in size, Testes of olle p, l/.api o!cr{/(('(l Harris fixed as soon as it eclosed from ['efrigcrated pup<-t> from Katonah State Park, BerkshiTe Co., :'lassachusetts, reared by H, p, WU.HE Ll\i. showed no dividing cells. It is essential to deter· mine the precise count for this and other so called napi races in view of the count shown below for P. 1'zrgZ1I1ClIS1,\' and thosf' for Palf'arctic population, (,;ce Discussion. brlm\" ) , 17. PinT.f virgilli(,!l.I'i.\' Edwards. l\" ,= 26. Counts were made in 13 nuclei (I) and 2 nuclei (11) in teste,; of 2 males [-1-26, 427 J reared from Iarv
had been refrigerated since late summer 1959 and removed to 20°C on 2 April 1960; both hatched 5 days later, and the testes were re moved and fixed 011 the same morning, The chromosomes are like those of P. napi /I/{/CdUlIllOUghii but then' is an additional very small element (see Dis cussion, below). 18. Picri.\' raprl mprl' (Linne). l\" = 25. Counts were made ill 162 nuclei ([) and 106 nudei (II), in testes of 13 males [322, 325, 326, 335, 338, 339, 3-1-0, 342, 3-1-3, 3-1-9, 350, 355, 3831 taken in New Haven Co., COlll1rcticut, -" to 1 9 Sept. 1959. Without exception these 268 nuclei show ex actlv 25 elements, Thus the small "m-chromosome" present in the nucleus or the cytoplasm in the .T apanese P. rap,l' rrllcivora is not ill the individuals we haY(' studied from Connecticut. (See Discussion, belo~ " , ) ] 9, Pinis brckcrii Edwards, N = 26. Counts were made in 8 nuclei ( I) and 6 nuclei (II) in testes of 2 males [35-1 , 35-3] taken at lola, Gun nison Co., Colorado, 18 J lily 1959, by R. "V, PEASE. J R, A third male taken at the same time showed no meiotic divisions, All the chromosomes are simi· lar in size, CHROMOSOMES PLATE
• • • • •• ••• • • •••• • • •••• • ••••• • ••• •••••• ••• • • •..: •••• ••• • • • •••••• ••• • ~ . • • •••• . • •• •• • •• •••••• • • 30b • •• 30a •• • • 3Ib • 3Ia
••• • ••• •••••••• .: .. • •••• : •• •• • •••• ...... • •••• •••••• •• ••• • • •••• 32 •• •••• 33a ••••• • 33b ••
• •• •• • •••• •••• • ••• •••••• •• ••••• • ••••• • ••• •••• • • ••••• •• • ••••••• ••• •• ••• • ••••• • •••• • ••• • • •••• 35b ••• •• •• 34b • 35a •• •• 34a •
••• • •• • •• • • ••••• ••• •• • ••• •• ••• • .: .; .. • ••• • ••• >6a • •••• • 36b •
Fig. 30a - Picris rllp" rap," (I) ; fig. 30b - ,arne (II); fig. 31a - P. napi macdllnnoughii (I); fig. 31h - ,arne (II); fig. 32 - P. virginiensis (I); fig. 33a - P. beckerii (I); fig. 33b - same (II); fig. 34a - P. oaideutalis (T); Jig. 34b - same (II) ; fig. 35a - P. (alyce (I) ; fig. 35b - same (II); fig. 36a -Aula monltste (I); fig. 36b - same (II).
47 48 MAEKI & REMINGTON: Chromosomes Vo1.14: 00.1
20. Pieris occidentalis Reakirt. N = 26. The chromosomes are all similar in size. This use of the name is not meant to imply any firm convic tion on the relation of occidentalis to protodice Boisduval & Leconte or to calyce. The insect we are calling occidentalis is very similar to protodice of the eastern states and may well be the same species and not even a worthy subspecies. It tends to be fairly common at middle altitudes in Colorado, al though it sometimes flies to the tops of the highest peaks. It should be re membered that in the East P. protodice is :a characteristically restless butter fly with extensive emigration going on all the time; P. protodice is often found in Connecticut, sometimes even breeding in large numbers, but it is never a permanent resident and temporary colonies do not survive most, if any, winters. Its western population (or perhaps distinct species), occidental is, apparently has the same long-distance movement and may turn up ,anywhere in Colorado. In contrast to BROWN, et al. (1956), we regard calyce as a very different entity and are inclined to believe that it will be recognized as a dis tinct species when more is known of its biology (and perhaps morphology). It is consistently much smaller than ocridentalis, is restricted to high altitudes (we know it well in Boulder County and Gunnison County), and has a dif ferent aspect in color, markings, and shape from all protodice-occidentalis pop ulations known to us. The insect we call calyce is not the spring brood of orcidentalis, which closely resembles form "vernalis" of the eastern protodice. None of these problems affects the use of chromosome characters with which this paper is concerned, because we have found no chromosomal differences be tween calyce and occidentalis. It would of course have simplified the taxono my if calyce had turned out to have a different number, as P. virginiensis does. Our counts of occidentalis were made in 86 nuclei (I) and 47 nuclei (II) in testes of 4 males: 3 taken at Gothic, el. 9,500', Colorado, 28 and 29 July 1959, [143, 155, 156J and 1 male [278J taken near Somerset, el. 7,800', Colorado, 15 August 1959. All these males had large testes. 21. Pieris enlycp Edwards. N = 26. Counts were made in 23 nuclei (I) and 9 nuclei (II) in testes of 5 males taken at Copper Lake, el. 10,500', Gunnison Co., Colorado, on 1 August [180-1, 180-2, 180-3, 180-5J and 7 August 1959 [204]. One of the [180J specimens seems to be occidentalis, not enlyce. Three other males, from Copper Lake, Gothic, and Cumberland Pass, showed no meiotic divisions. The chromosomes are ,all similar in size. The gonads were rather small, and the chromosomes showed a poor affinity for the stain, a condition commonly found in Nymphalidle with imaginal winter dia pallse and in various high altitude butterflies. (See I'emarks under P. occi den talis, above). 22. A scia monuste (Linne). N = 27. Counts were made in 14 nuclei (I) and 1 nucleus (II) in testes of 2 males [M 4-1, M 4-3 J taken at Ciudad Victoria, 1 August 1959. A third male taken at the same time shows no meio tic divisions. One chromosome is much smaller than the others. CHROMOSOMES PLATE 6
;47at
Fig. 37a - Achalarus toxeus (I); fig. 37b - same (II; n= 16); fig. 37c - same (II; n=17 ) ; fig. 38 - Erynnis icelus (I); fig. 39 - E. persius (I); fig. 40 -E. baptisi(e (I); fig. 41 - Grais stigmaticus (I); fig. 42 - Ochlodes syl'IJanoides (I); fig. 43 - Nastra I'herminieri (I); fig. 44 - Euchloe ausonides (I); fig. 45 - Colias eurytheme (I); fig. 46 - C. philodice (I); fig. 47a - C. meadii (I); fig. 47b - C. meadii (II); fig. 48 - Zerene cesonia (T).
49 PLATE 7 CHROMOSOMES
Fig. 49a - ilntcos tlorindr (I); fig. 49b - same (II); fig. 50 - Pha:bis philea (I); fig. 51a - Kricogonia lyside (I); fig. 51b - same (II); fig. 52 - Eurt'lna pro terpia (I); fig. 53 - E. 11!cxirana Of hoisdu'Valiana (II); fig. 54 - Appias drusilla (I) ; fig. 55 - Pip/·i ... rap,e rap" (I); fig. 56 - P. napi macdunnolLghil (I); fig. 57 -Po calyce (I) ; fig. 58 - P. neriden!alis (I); fig. 59 - P. ",'ckai (I); fig. 60a - Ascia manu.'t, (I) ; fig. 60b - same (II).
50 1960 .loumal of Ihe Lrpidopterists' Socifiy 51
Table 2.' CHROMOSOME NUMBERS OF THE HESPERIOIDEA.
Species Number (n) Division Reference ------1. HESPER1IDlE A. CceliadiniC: Bibasis aqlliiina (Speyer) 29 (1; (I) Maeki, 1953 Choaspes benjaminii (Guerin) 31 (1; (I) Maeki, 1953 B. PyrgilliC: .lCHALARUS TUXEUS (Plotz) 16 (1; (I, II) Present paper CHlOIDES C.'lTlLLUS (Cramer) 31 (1; (I) Present paper Spia/ia orbiter (Hubner) 30 (1; (II) Lorkovic, 1941 Pyrglls malv(e (L.) 31 (1; ( II). <;' (I) Fed erley, 1938 Lurkovic, 1941 Pyrglls onopordi (Rambur) 30 (1; (I, II ) Lorkovic, 1941 Pyrglls serrat-u/(e (Rambur) 30 (1; (I) Lorkovic, 1941 Pyrglls alvells (Hubner) 24 (1; ( I, II) , <;' (I) Federle]!, 1938 Lorkovic, 1941 Carcharodus aite,e (Esper) 31 (1; (1, II) Lorkovic, 1941 Carcharodus lavatherd! (Esper) 30 (1; (I, II) de Le"e, 1953 ErynTlis montanztS (Brem.) 31 (1; ( I, II) Maeki, 1953 ErynTlis lages (L.) 31 (1; (I, II) Lorkovic, 1941 ERYNNIS lCELUS (Scudd.&Burg.) 30 (1; (I, II) Prbent paper ERYNNlS JUVENALIS (Fab.) 30 (1; (I, II) Present paper ERYNNlS HORATlUS (Sc. & B.) 31 (1; (I, II) Present paper ERYNNlS PERSIUS (Scudder) 31 (1; (I, II) Present paper ERYNNIS BAPTISUE (Forbes) 31 (1; (I, II) Present paper ERYNNIS LUCILIUS (Sc. & B.) 31 (1; (I, II) Present paper CRUS STlGMATlCUS (Mab.) 31 (1; (I, II) Present paper Daimio tethys (Men.) 30 (1; (I) Maeki, 1953 C. HesperiiniC: Thymeiil'1Ls lineola (Ochs.) 29 (1; (I), <;' (1) Federle)', 1938 Orh/odrs venala (Br. & Grey) 29 (28) ;t; (I, II), <;' (1, II) Federle]!, 1938 Lorkovic, 1941 OCHLOf)ES SYLVANOIDES(Bd.) 29 (1; (I, II) Present paper Ochlodes orhrarea (Brem.) [Japan] 24 (1; (I) Maeki, unpublished NASTRA L'HERMINIERI (Latr.) 30 (1; (I, II) Present paper Thoressa varia (Mur.) 31 (1; (II) Maeki, 1953 Polytremis pellucida (Mur.) [Japan] 16 (1; (1) Maeki, unpublished Pelopidas mathias (Fab.) [Japan] 16 (1; (I) Maeki, unpublished Partlara gilitata (Bl'. & Grey) 16 (1; (I) Maeki, 1953
2. 'VIEGA THYMIDlE A. Megathymi[l 'Table 1, for the P"piliollid Table 3. CHROMOSOME NUMBERS OF THE PIERlDlE. ------_._-- _ . . ------~- Number (n) Division Reference A. Pierin;e: Anthocaris JColymus Butler 31 6 (I, II) Maeki, 1953, 1959 Eurh/or cardamines (L.) 31(-32) ,1; (I, II),9 (1) Federley, 1938 Lorkovic, 194-1 Euchloe crameri Butler 31 ;t; (1, II) L'lrkovic, 194-1 EUCHLOE AUSONIDES Lucas 31 ;t; (I, II) Present paper Col iaJ aouus (L.) 31 ;t;(I,II),9(I) Lorkovic, 194-1 Federley, 1942 COl.llIS EURYTHEME Bdv. 31 ;t; (I, II) Present paper COLlAS PHILODICE (C'n>dart) 31 ;t; (I, II) Present paper COLlAS ALEXANDRA Edw. 31 (; (I, II) Present paper COLllIS SCUDDERII Reak. 31 6 (I, II) Present paper Colias hyalr (L.) 31(-32) 6(I,II),9(I) Lorkovic, 194-1 Federley, 1942 Colias eratr (Esper) 31 (; (I, II) Maeki, 1953, 1959 Colias paloma (L.) 31(-32) ;t; (I, II), 'i' (I) Federley, 1938, 1942 Maeki, 1959 Collas nasies Bdv. 31 9 (I) Federley, 1942 Colias hecla Lefebre 31 'i' (1) Federley, 1938, 194-2 COLlAS MElIDIl Edw. 31 6 (I, II) Present paper ZERENE CESONlA (Stoll) 31 6 (I, II) Present paper G onepteryx rhamni (L.) 31(-32) 6 (I, II) , 'i' (1) Beliajeff, 1930 Federley, 1938 Lorkovic, 194-1 Maeki, 1959 GOIll'pleryx ma/zaguru (Gistel) 31 6 (I, II) Maeki, 1959 ANTEOS CLORINDE (Godart) 31 6 (I, II) Present paper Hehomoia glaucippe (L.) 17 6 (I, II) Maeki, 1959 PHmBIS PHILEA (Joh.) 31 6 (I, II) Present paper KRICOGONl/J LYSIDE (Godart) 31 6 (I, II) Present paper Eurema !tela (Bdv.) 29 6 (I, II) Maeki, 1959 Eurema "ecabe (L.) 31 6 (I, II) Maeki, 19 53 , 1959 EUREMA PROTERPIA (Fab.) 31 6 (I, II) Present paper EUREMlI [MEXIClINA Bdv. or BOlSDUVALJANA F. & F.J 31 ;t;(I,Il) Present paper EUREMA NICIPPE (Cramer) 31 (; (I, II) Present paper EUREMA USA (Bdv. & Lee.) 31 ;t; (I) Present paper APPlAS DRUSILlA (Cramer) 32 ;t; (1, II) Present paper A poria cratcegi (L.) 25(-26) ;t; (I, IT), 'i' (I) Kernewitz,1914,1951 Beliajeff, 1930 Federley, 1938 Lorkovic, 1941 Maeki, 1953, 1959 Aporia hippia (Brem.) 25 ;t; (I, II) Maeki, 1959 1960 Journal of the LI>pidopterists' Soriety 53 Table - continued. .. Pieris hrass;ree (L.) 15 $ (I, II), <;> (I, IT) Henking, 1890 Doncaster, 1912 Beliajeff, 1930 Federley, 1938, 1942 Lorkovii', 1941 Pieri ... rapee rap{e (L.) 25(-26?) is (I, II), <;> (I) Beliajeff, 1930 Federle)", 1938 Lorkovii', 1941 Present paper Pieri ... rapa (rU(l'/Jorli Bd\". 26(-25) $ (T, II ) :v1aeki, 1953, 1959 Pieri ... mann; Mayer 25 3 (I, II) Lorkovic, 19+1 Pieri ... iJryonia Ochs. 25 3 (I, II) Lorkovic, 19+1 Pieri ... napi napi (L.) 25 $ (I,II),<;>(l) Henking, 1890 Federle)", 1938 Lorkovic, 19+1 P. N. M,-lCDUIYNOUGHI1 Rem. 25 3 (I, II) Present paper Pieris napi neJl ... Fruhst. 26 3 (I,II) Maeki, 1959 PlERIS FlRGINIENSIS EdlY. 26 $ (1, II) Present paper Pieris ergane Hubner 26 3 (I, II) Lurkovic, 19+1 Pie/·is me/ele Mell. 27-31 3 (I,II) Maeki, 1953 Pie/·is daplidire (L.) 26 3 (1, II) Lorkovic, 1941 PlERIS BECKERIl Ed". 26 $ (I, II) Present paper PlERIS OCClDENL1US Reak. 26 3 (I, II) Present paper PlERIS C4LYCE Edw. 26 3 (I, II) Present paper ASCIA MONUSTE (L.) 27 3 (I, II ) Present paper B. Oismorphiin;e: Leptidea sinapis (L.) 26-41 $ (I,II),<;> (1) Feder lcy, 1938 Lorkovic, 19+1 Leptidea morSel Fenton 54 3 (1) Lorkovic, 19+1 Maeki, 1958, 1959 Leptidea amurenSlS (Men.) 61 3 (I, II) Maeki, 1958, 1959 Leptidea duponrhe/i Staud. 104 3 (I) Lorkovic, 1941 DISCUSSION Tables 2 and 3 show the chromosome numbers of the 32 species of Hes perioidea and -+8 of Piericlx for which counts have now been recorded, Of the 36 species described in the present paper 34, plus 1 subspecies, are new to cytology and are shown in capitals in the Tables. Some major groups are notably constant in number. Of the 19 known Pyrginre, 17 have n = 30 or 31. The count of 16 for AchalaT"lts toxelts is an extreme variant bllt l'an be accounted for by 1 + 1 fusions of all but one chromosome (the X-chromosome?). The 9 Hesperiinre shown in Table 2 are diverse, but we will soon publish accounts of several more species having n = 29, and this seems to be the most usual number for the many small brown temperate-region hesperiines. The 3 n = 16 Asiatic species appear to )4- MAEKI & REMINGTON: Chromosomes Vo1.14: no.! be in a distinctive phylogenetic line. Their caryotype is remarkably similar to that of A. toxeus. Our finding of n = 48 for the hesperiine Asholis capuci nils (Lucas), to be reported in detail in ou r forthcoming supplementary pa per, is an extreme departure from the previously published counts for any Hesperiid~. The chromosomes of the Pierin~ are now well enough known to show that on cytological grounds there are two very discrete groups: the Euchloini with 31 as the usual base number and the Pierini with 25-26 as most char acteristic. There is no cytological support for the separation of the Colias relatives from the Euchlo(' relatives. The known Amt:'rican Pierid~ have no largt:' variants in number, A seia monus!c and A ppias drllsilla having only one more chromosome than their relatives. In tht:' known Old World Pieri n~ two species have large differences from their neart:'st relations: Pieri.l· hrassica: (n = 15 instead of 25 or 26) and H rholl/oia glaucippe (n = 17 in stead of 31), and we will soon describe an African L rptosia with n = 12. It will be of great interest to work Ollt the numbers for the many American Dismorphiin~, in view of the wide numerical range and the suggestion of polyploidy in the one Palearctic dismorphiine genus, Leptidra. The family lVlegathymid~ is structurally and biologically divergent and specialized as compared to the Hesperiid~, and the megathymids also prove to be distinctive chromosomally. All 3 known species (and genera) have totally different numbers: n = 21, n = 27, and n = 50. The latter is the highest known count for any Hesperioidea. Too few of these remarkable Skippers have been worked out for safe generalizations to be made. We in tend to give this group special attention, with the help of the STALLINGS. TCfnHR, and FREEMAN group of specialists. The introduced Pieris rap,(' rapa' is believed to have come to North America from Europe in the 19th Century. Our many counts all agree with those of BELIAJEFF (1930) and LORKOVIC (1941) for eastern European material. FEDER LEY (1938) reported n = 26 for both spermatocyte and oocyte divisions in P. rapt(, from Finland. There is a need for counts from a substantial series of Scandinavian, especially Finnish, P. rapd' to determine how regular is the haploid number of 26 ill that region and whether the 26th t:'lement is a 110rmal chromosome or a m-chromosome. (See our remarks on the m-chromosome in our first paper, page 200.) In the JapanEse P. rapt? crurivora there is one m-chromosome in addition to the 2.5 normal chromo somes, and this minute element was found (l\Iaeki, 1959) sometimes among the normal chromosomes and sometimes in the cytoplasm outside the nucleus. If Finnish P. rap,c consistently have the m-chromosome there will be a sug gestion of phylogenetic affinity with the Japanese race. If there is a 26th normal chromosome there will be the possibility that hybridization experi ments will show that the Finnish stock is not true rap({' but an unrecognized sibling or a member of a 26-chromosome species such as P. ergane. A similar situation exists in so-called Pieris napi. HEN KING (1890) , FEDERLEY (1938 ) , and LORKOVIC (1941) found n= 2.5 in spermatocyte 1960 .Toum"l of the Lepidopterists' Society )) divisions in European material ( FEDERLEY also reported n = 23 in a fe male). We found n = 25 regularly in race lIlacdunnoughii in Colorado. MAEKI (] 959) showed that the number is 26 consistently in the Japanese "subspecies" Tlnis and that the extra chromosome is apparently a regular autosome, not a m-chroIl1osome. (His earlier report (1953) of n = 25 was corrected in the later paper.) It is now suggested that nesis is a species dis tinct from true napi. as is certainly true for the North American virginiellsis (n = 26). I n the eastern U. S. A. P. virginiensis is mainly more southern than P. 1lapi but has an overlap zone of sympatry in ~1asachusetts and Ver mont and perhaps to the west as well. It is univoltine and very early in its flight, whereas napi is commonly bivoltine and even its first brood is later than the single brood of virginicnsis. There is some tendency for foodplant separation, with P. virginiensis larv~ always on Dentaria and P. napi on sev eral Crucifera: including De1ltaria. Our finding of a chromosome difference is a piece of clinching evidence for the full species status of virgi1lie1lsis. and the long debate on the question appears to be ended. The cytological data are not significant in clarifying the status of mem bers of three other complexes we have examined. In these there are no differ ences in chromosome number. This Ileed not indicate conspecifity (and cer tainly does not in the second and third complexes), since separate species often have identical haploid numbers. Pieris occidentalis and P. calyce (see notes above) both have n = 26. In the sibling species group including F-ryn nis baptisice, F. lucilius, and F-. persius, all three prove to have n = 31. The eleven known species of Colias, some phenotypically extremely alike, all have n = 31. However, the five Colias we have studied have 7 large chromosomes clearly distinguishable in the metaphase plate of the primary spermatocyte division; we found these larger chromosomes still recognizable in the second ary spermatocyte division only in C. alexandra and C. scudderii: possibl y this is a significant character. SUMMARY ]. Chromosome cOllnts are presented for 11 species of Hesperiid~, 3 of \Iegathymid~, and 22 of Pierid~. All the Hesperiid~ are species new to cytology. N 0 \Iegath Y l11id~ had previously been studied. Of the Pierida:, 20 species are likewise new and another count is the first for an American sub species (Pieris napi macdullnoughii). The cytologically new species are: A chalarus toxeu!' (l\Iexico), C hioides ratillus (Mexico), Frynnis icelusJ j l{ venalis, horatius, pen'ius. baptisi{F, and lurilius (all Connecticut) , Grais stigmatirZls (\Iexico), Ochlodn sylva710ides (Colorado) , N astra l' herlllinieri (Connecticut), 111egathYlllus viola: (VIexico) , Stallingsia maculosa (Texas), A gathymus mariff (Texas), Fuchloe ausonides (Colorado), Colias eury t heme and philodicc (Connecticut) , C. alexandra, scudderii, and meadii (all Colorado), Z ercnc cesonia (Mexico), A ntcos clorinde. P hcebis philea, Kri cogonia lyside, Eurcma proterpia, Ilicippe, and [mexica1la or boisduvaliallaJ (all Mexico), r.:. lisa (Connecticut), A ppias drusilla (Mexico), Pieris vir- 5~ MAEKI & REMINGTOl'>: Chromosomes Vo1.14: no.l ginicnsiJ (i\lassachusetts), Pieris beckerii, occidentalis, and calyce (all Colo rado), and dscia lIIonustl' (lVlexico). All these counts art' from spermatocyte divisions. 2, :\Ieiotic divisiom are numerous in most adult. flying males of Pieri dct' and Hesperiid::e. lV[eiosis has almost or entirely ended by the time of eclosion in males of thr lVlegathymid::e. the five high mountain Hesperiid::e, and the many early spring Frynni... hrizo examined by us. 3. The haploid number tends to be 30 or 31 for Pyrgin::e, 29 for Hes periin::e. 31 for Euchloini (including the Colias group) and 25-26 for Pier ini. Some deviant species have been found in each of these groups. The num brrs for :\'Iegathymid::e are widely scattered, the three known species (rach in a separate genus) having n = 21, 27. and 50, respectively. i-. Thr North American sibling species, Pieri ... napi and virginiensis, have haploid numbers of 25 and 26, respectively. Japanrse supposed P. nap·i ("subspecies" nesis) has n = 26. The Japanesr P. rapee crucivora has an ex tra minute element not present in the European and American P. rap,e rapd!. I n both cases thr J apanesr forms mav actually provr to be separate species rather than subspecies. 5. Thrre other complexes of possible or positive sibling species prove to have no difference in number among the similar forms: Pieris oecidenlalis and (alyce; ErY!llIis persius. baptisid!, and lueilius; and Colias spp. 6. The haploid number is only mentioned for A sholis capueinus, Och lode.r (Jchrarea, Polytrrlllis prllucida, and Pelopidm II/athias; descriptions and fu 11 records will be reported in later pa pel's. ACKNOWI.EIlGEMENTS vVe are again grateful to Dr. and Mr,. Ross B. DICKSON of Cuidad Victoria, Mexico, f(Jl' fine facilities, to P . SHELDON and ERIC E. REMIl'>GTON, to Dr. J. R. TURN ER, and to DON R., VIOLA T., and JACK STALLINGS for field assistance in Mexico, to ERIC E. REMINGTOl\ and ROGER W. PEASE, JR. for many of the Colorado and Connecti cut specimem. DON B. STALl.lNGS sent us the living pupre of Stallingsia maculosa. JOHl'> M. BURl'>S (for Erynnis) and ALEXANDER B. KLOTS (for Eurema) kindly checked determinations in their special groups. This work was supported in all its parts by a research grant (C; 3830) from the U. S. National Science Foundation. References Baliajeff, N. K., 1930. Die Chromosomenkomplexe und ihre Beziehung zur Phylogenie bei den Schmetterlingen. Zeitsrhr. induk. A bstamm. - und rererbungsl. 54: 369-399. Doncaster, L., 1912. The chromosomes in the oogenesis and spermatogenesis of Pieris hrassiccE, and in the oogenesis of A braxas grossulariata. Iourn. genetics 2: 189-200. Federle)" R., 1938. Chromosomenzah len finn landischer Lepidopteren. I. Rhopalocera. Hereditas 24: 397-464, 47 figs . . --_ .. _._, 19+2. Chromosnmenzahlen von vier Tagfaltern von ozeanischen Inseln. Her editas 28: 493-495. Henking, R., 1890. U ntersllchungen liber die erster Entwicklungsvorgange in den Eiern der Insekten. I. Das Ei von Pieris brassicd! L. nebst Bemerkungen liber Samen lind Samenbildung. Zeitschr. wiss. Zool. 49: 503-564, pls.24-26. 1960 lournal of the Lepidopterists' Society 57 Kernewitz, B., 1914. tIber Spermiogenese bei Lepidopteren. Zool. Iluz. 45: 137-139 ...... , 1915. Spermiogenese bei Lepi.dopteren mit besonderer Berucksichtigung der Chromosomen. Ilrchiv. Naturgeschichte (II) 81: 1-34, 3 pIs., 14 figs. de Lesse, H., 1953. Formules chromosomiques de Boloria aquilonaris Stichel, B. pales D. et Schiff., B. Ilap(£a HoHm. et quelques aulre; Lepidopteres Rhopaloceres. Rev. franc. lepid. 14: 24-26, 1 pI., 5 figs. Lorkovic, Z., 1941. Die Chromosomenzahlen in der Spermatogenese der Tagfalter. Chrolllosoma 2: 155-191, 13 figs. Maeki, K., 1953. Chromosome number of some butterflies (Lepidoptera-Rhopalocera). Jap. journ. genetics 28: 6-7, 5 figs . . _. .. _.... _., 1958. On the cytotaxonomica I relationship in Le pfid f(l (Lepidoptera-Rhopalo cera). lap. journ. genetics 33: 283-285, 6 figs ...... , 1959. A chromosomal study in fifteen species of the Japanese Pieridx (Lepi doptera-Rhopaloccra). Kwansei Gakuin Uni'l!. annual studies 7: 361-368, 32 figs . ...•...... _, &: C. L. Remington, 1960. Studies of the chromosomes of North American Rhopalocera. 1. Papilionidoc . .!ourn. lepid. soc. 13: 193-203, 3 pis. Department of Zoology, Yale University, New Haven, Conn., U. S. A. A CORRECTION ON HESPERIA PAWNE"~ IN MICHIGAN Since the publication of my article entitled, "Observations of Hesperia pawnee in Michigan" (Lepid. news 12: 37-40; 1958), I now realize that a serious error in determination was made. All of the records and observations for H. pawnee Dodge in lVlichigan referred to in this article should be those of H. ottoe Edw. This error was first called to my attention by Mr. C. DON MACNEILL of the California Academy of Sciences after I had sent him specimens determined by me as pawnee. I then shipped to MACNEILL, later to Dr. A W. LINDSEY, additional pawnee specimens (my determinations) of both sexes from several localities over a wide range of dates, including the pair originally determined as pawnee by Mr. W. D. FIELD of the U. S. Na tional Museum, for further examining. In each case the specimens were found to be Hesperia ottoe! Dr. LINDSEY stated that my dates of capture, June 19 to August 9, were sufficient to separate the two species, as pawnee flies later than ottoe in the same area. Recently, in checking the left valve of several males in my collection, I found the terminal tooth shorter than the basal tooth - characteristic of ottoe. It is entirely possible that H. pawnee may occur in :Michigan in the same habitat as that of ottoe but during late August and September. In time, I hope to explore this possibility and will report any interesting results. M. c. NIELSEN, 3415 Overlea Dr., Lansing 17, Mich., U. S. A.