Animal Diversity Web

Ge­o­graphic Range

His­tor­i­cally, the range for regal frit­il­lar­ies was from Nova Sco­tia south to west­ern North Car­olina, and west­ward from north­ern Arkansas to east­ern Col­orado and Man­i­toba, Canada. Cur­rently, there are only two known pop­u­la­tions re­main­ing east of the Mis­sis­sippi River. The largest of these oc­curs in cen­tral Penn­syl­va­nia and a sec­ond, smaller one is found in West Vir­ginia. (Bar­ton, 1993; Pyle, 1995; Williams, 2002)

• Biogeographic Regions
• nearctic
  • native

Habi­tat

Regal frit­il­lar­ies are con­sid­ered prairie spe­cial­ists and in the Mid­west are known to occur in a va­ri­ety of grass­land habi­tats in­clud­ing moist tall-grass prairies, wet fields and mead­ows, vir­gin grass­lands, old fields, and flood­plain for­est open­ings and edges. (Pyle, 1995; Nielsen, 1999; Scott, 1986; Swen­gel, 1996; Bar­ton, 1996; Struttman, ; Swen­gel and Swen­gel, )

• Habitat Regions
• temperate
• terrestrial

• Terrestrial Biomes
• savanna or grassland

Phys­i­cal De­scrip­tion

The upper sur­face of the forewings of both males and fe­males is deep or­ange with black marks and white spots along the outer wing mar­gins. The un­der­side is a mir­ror image of the upper sur­face. The un­der­sur­face of the hind­wing is a rich brown­ish-black with white spots. The upper sur­face of the hind­wings in both sexes has an iri­des­cent blue-black back­ground with two rows of spots. These spot rows are one of two char­ac­ter­is­tics used to vi­su­ally dif­fer­en­ti­ate fe­males from males. The fe­males have two rows of cream-col­ored spots in con­trast to an or­ange outer row and a cream-col­ored inner row on the males' wings. The sec­ond char­ac­ter­is­tic is size dif­fer­ence, with regal frit­il­lary fe­males larger than males. Their bod­ies are brown­ish-black.

Regal frit­il­lary eggs are con­i­cal with ir­reg­u­lar ridges run­ning from the crown to the base. They are cream col­ored when first de­posited and ap­pear to darken slightly over time. Lar­vae have been de­scribed as being ei­ther vel­vety black with yel­low­ish-or­ange blotches or yel­low to yel­low­ish or­ange with black blotches. There are six rows of black bris­tled spines. The lar­vae have a black mid­dor­sal line, two black trans­verse lines be­hind the dor­sal and sub­dor­sal spines, yel­low­ish mid­dor­sal and lat­eral stripes, dor­sal spines sil­ver­ish at the base, sub­lat­eral and lat­eral spines or­ange at the base. The head is black with orangish col­oration on the top rear por­tion. (Hol­land, 1931; Kop­per, et al., 2002; May­nard, 1891; Nielsen, 1999; Pyle, 1995; Scott, 1986)

Scott (1986) de­scribes the pupae as light mot­tled brown with pink tinge, small black spots on the wings and tho­rax, trans­verse bands of yel­low on the ab­domen, and short, dor­sal cones. (Scott, 1986)

• Other Physical Features
• ectothermic
• heterothermic
• bilateral symmetry

• Sexual Dimorphism
• female larger
• sexes colored or patterned differently

• Range wingspan

  6.5 to 10.2 cm

  2.56 to 4.02 in

De­vel­op­ment

Eggs are laid in the late sum­mer through early fall and hatch about three weeks later. These first in­star lar­vae usu­ally eat their egg chorion be­fore im­me­di­ately crawl­ing into the leaf lit­ter and en­ter­ing into di­a­pause, over­win­ter­ing with­out feed­ing on plant ma­te­r­ial. In early spring the lar­vae begin feed­ing on vi­o­let leaves. They will go through five molts be­fore en­ter­ing the pupal stage, which lasts about 17 days. Lar­val de­vel­op­ment was fol­lowed in 86 cap­tive lar­vae by Wag­ner et al. (1997). Each of the first five in­stars lasted from an av­er­age of 3.6 to 6.6 days. The final in­star lasted an av­er­age of 17.1 days. Males begin emerg­ing in early June with fe­males fol­low­ing ten days to two weeks later. Opler and Krizec (1984) state that emer­gence con­tin­ues through late Au­gust, how­ever Bar­ton (1996) found a few freshly emerged males in early Sep­tem­ber. Fe­male emer­gence ap­pears to end in mid-July. Few males are still fly­ing by Au­gust, and fe­males die off by mid-Sep­tem­ber. (Weed, 1926; Opler and Krizek, 1984; Hol­land, 1931; Kop­per, et al., 2002; Bar­ton, 1996; Wag­ner, et al., 1997)

• Development - Life Cycle
• metamorphosis
• diapause

Re­pro­duc­tion

Regal frit­il­lar­ies are uni­vol­tine and begin mat­ing soon after the fe­males emerge in mid-June. Males spend most of their time pa­trolling for fe­males and Kop­per (2002) ob­served three types of flight be­hav­ior. The first type was the ac­tual pa­trolling flight where the male flew up­wind from 10 cm to 50 cm above the ground for dis­tances of 5-30 m. There was a sec­ond "tack" flight (short, rapid) that was re­peated one to sev­eral times fol­lowed by the third type where the male flew up into the air for 5-10 m and flew 20-50 m down­wind in fast flights be­tween 1 and 2 m above the ground. If no fe­males were en­coun­tered, they re­sumed their up­wind flight. Bar­ton (1996) ob­served males fly­ing low over veg­e­ta­tion then drop­ping down and pre­sum­ably search­ing for fe­males around the bases of blue­berry bushes Vac­cinium spp. and scrub oaks Quer­cus ili­ci­fo­lia. When two males come into each other’s' path, they often will spi­ral up into the air then con­tinue on their pa­trols. They have also been ob­served chas­ing other in­sects while pa­trolling, in­clud­ing mon­archs Danaus plex­ippes, black swal­low­tails Pa­pilio polyx­enes as­te­r­ias, great span­gled frit­il­lar­ies Spey­e­ria cy­bele and aphrodite frit­il­lar­ies Spey­e­ria aphrodite ( B.J. Bar­ton, per­sonal ob­ser­va­tion, Kop­per et al. 2001). (Bar­ton, 1996; Kop­per, et al., 2001a; Kop­per, et al., 2002)

When a fe­male is en­coun­tered, males give chase fly­ing a cir­cu­lar pat­tern be­hind them. Un­re­cep­tive fe­males fly up to 35 m into the air, often with sev­eral males in pur­suit, then drop rapidly into the veg­e­ta­tion (Bar­ton 1996). Ei­ther the fe­male ef­fec­tively loses the males, or courtship rit­u­als con­tinue. Bar­ton (1996) ob­served a suc­cess­ful pair­ing in the Penn­syl­va­nia pop­u­la­tion. A fe­male was ob­served ex­hibit­ing ovipo­si­tion be­hav­ior, and a male flew down and began fol­low­ing her, quiv­er­ing his wings. She con­tin­ued with the ovipo­si­tion be­hav­ior for ap­prox­i­mately 10 min­utes be­fore start­ing to quiver her wings at a faster rate than the male. The fe­male crawled down into the veg­e­ta­tion and stopped the wing move­ment, again dip­ping her ab­domen. The male po­si­tioned him­self next to the fe­male and slowly beat his wings against the fe­male. They both took flight and landed a short dis­tance away, where the male re­sumed the wing beats. Cop­u­la­tion then oc­curred and they paired for 1 hr and 43 min. At one point the pair took flight with the male car­ry­ing the fe­male. The fe­male was seen ex­hibit­ing oviposit­ing be­hav­ior prior to this event, in­di­cat­ing she may have pre­vi­ously mated. This is in con­trast to the find­ings of Kop­per et al. (2001) who state that fe­males mate only once. (Bar­ton, 1994; Kop­per, et al., 2001b)

• Mating System
• polygynandrous (promiscuous)

Regal frit­il­lar­ies pro­duce one brood per year (uni­vol­tine). Mat­ing be­gins soon after fe­males emerge and con­tin­ues through early July. Fe­males enter re­pro­duc­tive di­a­pause near the end of July and be­come ac­tive again in late Au­gust when they begin oviposit­ing. Kop­per et al. (2001) stud­ied the re­pro­duc­tive char­ac­ter­is­tics of fe­males in a north­east Kansas pop­u­la­tion specif­i­cally look­ing at re­pro­duc­tive di­a­pause. By mon­i­tor­ing he­molymph ju­ve­nile hor­mone titers, ovar­ian de­vel­op­ment, and fat body uti­liza­tion, they de­ter­mined that fe­males mate only once. Oo­ge­n­e­sis (the for­ma­tion of eggs) and fat body de­ple­tion began in late Au­gust/early Sep­tem­ber, in­di­cat­ing the fe­males un­dergo re­pro­duc­tive di­a­pause in mid-Au­gust. Ovipo­si­tion be­gins soon after. When fe­males are ready to oviposit, they will drop into the veg­e­ta­tion and walk around prob­ing with their ab­domen until the ap­pro­pri­ate site is se­lected. They will then de­posit the egg and fly off to find an­other site. (Kop­per, et al., 2001b; Bar­ton, 1996)

• Key Reproductive Features
• semelparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

• Breeding interval

  Regal fritillaries are univoltine, breeding once per year.

• Breeding season

  The breeding season is from July through September.

• Range eggs per season

  2000 eggs per female in captivity (Wagner 1997) (high)

There is no parental care ex­hib­ited by regal frit­il­lar­ies.

• Parental Investment
• no parental involvement

Lifes­pan/Longevity

The longest life span recorded in the wild from mark-re­lease-re­cap­ture stud­ies in Penn­syl­va­nia was at least 69 days (sex un­known) (Bar­ton 1996). A fe­male is known to have lived in cap­tiv­ity for four months (Bar­ton 1993). As the but­ter­flies age, they ex­pe­ri­ence wing wear which even­tu­ally hin­ders their abil­ity to fly. This makes them vul­ner­a­ble to preda­tors and also makes travel to nec­tar sources dif­fi­cult. Their lifes­pan is most likely lim­ited by the de­te­ri­o­ra­tion of their bod­ies, and in the case of fe­males, loss of nec­tar re­sources due to changes in the sea­son. (Bar­ton, 1993; Bar­ton, 1996)

• Range lifespan
  Status: wild

  69+ (high) days

• Range lifespan
  Status: captivity

  120+ (high) days

• Typical lifespan
  Status: wild

  14 to 60 days

• Typical lifespan
  Status: captivity

  120 (high) days

Be­hav­ior

Regal frit­il­lar­ies are ac­tive within their home range, nec­tar­ing and en­gag­ing in re­pro­duc­tive ac­tiv­i­ties. They are day­time fliers and will often take cover in the shade dur­ing ex­tremely hot weather (Bar­ton, per­sonal com­mu­ni­ca­tion).

• Key Behaviors
• flies
• diurnal
• motile
• sedentary
• hibernation

Home Range

Adults of this species can travel con­sid­er­able dis­tances, but the ma­jor­ity stay close to their birth sites. Dur­ing a 1993 mark-re­lease-re­cap­ture study in Penn­syl­va­nia, the av­er­age dis­tance trav­eled by both sexes was 2.14 miles (3.4 km) from their ini­tial points of cap­ture (19% of re­cap­tured males and 5% of re­cap­tured fe­males ac­tu­ally trav­eled). The longest dis­tance trav­eled by a male was 6.3 lin­ear miles (10.1 km), and 4.3 lin­ear miles (6.9 km) by a fe­male. (Bar­ton, 1994; Bar­ton, 1993)

Com­mu­ni­ca­tion and Per­cep­tion

Regal frit­il­lar­ies use vi­sion to de­tect other an­i­mals and the world around them. They ap­pear to be sen­si­tive to vi­bra­tions as well. Bar­ton (per­sonal com­munca­tion) ob­served re­gals flush­ing from veg­e­ta­tion im­me­di­ately fol­low­ing a loud ex­plo­sion from ar­tillery. We have no in­for­ma­tion on the chem­i­cal senses of this species, but since other species of Spey­e­ria com­mu­ni­cate with pheromones, adults of this species prob­a­bly do too. Lar­val frit­il­lar­ies can taste chem­i­cals that allow them to choose their food plants. The only ob­served tac­tile com­mu­ni­ca­tion was a male beat­ing his wings slowly against a fe­male's body dur­ing courtship. (Bar­ton, 1994; Scott, 1986)

• Communication Channels
• visual
• tactile
• chemical

• Other Communication Modes
• pheromones

• Perception Channels
• visual
• tactile
• vibrations
• chemical

Food Habits

Regal frit­il­lary lar­vae are vi­o­let feed­ers and re­ported to use Viola pe­dat­i­fida, V. pa­pil­ionacea, V. lance­o­lata, V. pe­data, and V. prat­in­cola. In Penn­syl­va­nia, lar­vae are be­lieved to feed only on V. sagit­tata (Bar­ton 1996). They are con­sid­ered di­ur­nal her­bi­vores. (Bar­ton, 1993; Bar­ton, 1994; Bar­ton, 1996; Kop­per, et al., 2001a; Kop­per, et al., 2002; Scott, 1986; Weed, 1926)

Adult regal frit­il­lar­ies have a long pro­boscis that is used for in­sert­ing into flow­ers to ob­tain nec­tar. They feed on a va­ri­ety of nec­tar plants, most com­monly but­ter­fly­weed As­cle­pias tuberosa, iron­weed Ver­nonia bald­winii, pur­ple cone­flower Echi­nacaea au­gustafo­lia, blaz­ing star Li­a­trus spp., this­tles Cir­sium spp., and other milk­weeds As­cle­pias spp. Other recorded nec­tar sources in­clude Dept­ford pink Di­anthus arme­ria, moun­tain mint Py­c­nan­the­mum spp., Joe-pye weed Eu­pa­to­rium per­fo­lia­tum, bone­set E. mac­u­la­tum, gold­en­rod Sol­idago spp., Ca­lyo­phus seru­la­tus, Car­duus nu­tans, Schrankia nut­talli, Li­a­tris squar­rosa, L. as­pera, yarrow Achil­lea mille­folium, dog­bane Apoc­ynum cannabinum, Cen­tau­rea mac­u­losa, Chrysan­the­mum leu­can­the­mum, and black-eyed Susaun Rud­beckia serotina. (Bar­ton, 1993; Bar­ton, 1994; Bar­ton, 1996; Kop­per, et al., 2002; Scott, 1986; Weed, 1926)

• Primary Diet
• herbivore
  • folivore
  • nectarivore

• Plant Foods
• leaves
• nectar

Pre­da­tion

There is no in­for­ma­tion avail­able on anti-preda­tor adap­ta­tions by regal frit­il­lar­ies. Adults are sus­cept­able to pre­da­tion by birds, spi­ders, and pos­si­bly rob­ber flies. Known preda­tors in­clude the east­ern king­bird Tyranus tyranus, crab spi­ders (fam­ily Thomisidae), and black widow spi­ders La­trodec­tus mac­tans. (Bar­ton, 1996)

Com­mon preda­tors of lep­i­dopteran lar­vae in­clude par­a­sitic wasps, ants, and spi­ders.

• Known Predators

  • Eastern kingbird (Tyrannus tyrannus)
  • Crab spiders
  • Black widow spiders (Latrodectus mactans)
  • Parasitic wasps
  • Ants

Ecosys­tem Roles

Regal frit­il­lar­ies serve as hosts for par­a­sitic wasps and flies, and as food for birds and spi­ders. They may also serve as pol­li­na­tors.

• Ecosystem Impact
• pollinates

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Regal frit­il­lar­ies at­tract eco­tourists who are in­ter­ested in view­ing this rare species, thus bring­ing eco­nomic ben­e­fit to the nearby com­mu­ni­ties. The con­ser­va­tion ef­forts of groups pre­serv­ing the prairie habi­tats where regal frit­il­lar­ies occur pro­vide places for peo­ple to visit to enjoy a snap­shot of what the mid­west once looked like. Re­search ac­tiv­i­ties have en­hanced our knowl­edge of prairie ecosys­tems.

• Positive Impacts
• ecotourism
• research and education

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse af­fects of regal frit­il­lar­ies on hu­mans.

Con­ser­va­tion Sta­tus

Regal frit­il­lar­ies are not cur­rently on the IUCN Red List, CITES, or the US En­dan­gered Species list; how­ever, they are listed as en­dan­gered, threat­ened, or ex­tir­pated by sev­eral state gov­ern­ments. They are listed as en­dan­gered in the state of Michi­gan. In the east­ern U.S. where the species is most im­per­iled, ef­forts have been un­der­way by the Penn­syl­va­nia Air Na­tional Guard and var­i­ous pri­vate or­ga­ni­za­tions to pro­tect the habi­tat of the pop­u­la­tion in Penn­syl­va­nia. Other con­ser­va­tion groups such as The Na­ture Con­ser­vancy are ac­tively pro­tect­ing many known sites (Bar­ton, per­sonal com­mu­ni­ca­tion).

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  Endangered

Other Com­ments

Regal frit­il­lar­ies have been known by sev­eral com­mon names, in­clud­ing regal sil­verspot but­ter­fly, regal sil­ver­wing, and sil­ver Arg­ynne. Sci­en­tific names have changed as well and are as fol­lows: Pa­pilio idalia (Drury) 1773, Arg­yn­nis as­tarte (Fisher) 1858, A. ashtaroth (Fisher) 1859, A. in­fu­mata (Oberthur) 1912, A. dolli (Gun­der) 1927, and A. pal­l­ida (Eis­ner) 1942. (May­nard, 1891; Miller, 1992)

Williams (2002) be­lieves that eco­log­i­cal dif­fer­en­ti­a­tion may exist be­tween Mid­west­ern pop­u­la­tions and those in the east. The lar­vae in the Penn­syl­va­nia pop­u­la­tion eat Viola sagit­tata, a plant not used any­where else in their range. Habi­tat dif­fer­ences exist as well, with mesic con­di­tions found in the east and xeric in the west. Williams spec­u­lates that glac­i­ers ex­tend­ing into south­ern In­di­ana and Ohio dur­ing the Pleis­tocene may have di­vided re­gals into east­ern and west­ern pop­u­la­tions. The re­sults of mtDNA se­quenc­ing analy­sis sug­gest the Penn­syl­va­nia pop­u­la­tion is a dis­tinct lin­eage, and that they may have sep­a­rated from the mid­west­ern pop­u­la­tion about 400,000 years ago. (Williams, 2002)

Con­trib­u­tors

Matthew Wund (ed­i­tor), Uni­ver­sity of Michi­gan-Ann Arbor.

Barb Bar­ton (au­thor), Spe­cial Con­trib­u­tors.

Ref­er­ences

The Na­ture Con­ser­vancy. "Regal Frit­il­lary at Fort In­diantown Gap, Penn­syl­va­nia" (On-line ). Ac­cessed 02/18/03 at http://​nature.​org/​wherewework/​northamerica/​states/​pennsylvania/​preserves/​art824.​html.

Bar­ton, B. 1993. 1993 Field study of the regal frit­il­lary <<Spey­e­ria idalia>> at ... (site name deleted). Re­port to the De­part­ment of De­fense: un­pub­lished.

Bar­ton, B. 1996. Final re­port on the Regal Frit­il­lary 1993-1995...(site name deleted). Re­port to the De­part­ment of De­fense: un­pub­lished.

Bar­ton, B. 1994. The sta­tus re­port of the regal frit­il­lary at ... (site name deleted). Re­port to the De­part­ment of De­fense.

Glass­berg, J. 1999. But­ter­flies Through Binoc­u­lars - The East. New York City, New York, USA: Ox­ford Uni­ver­sity Press.

Hol­land, W. 1931. The But­ter­fly Book. Gar­den City, NY: Dou­ble­day, Doran, and Com­pany.

Ift­ner, D., J. Shuey, J. Cal­houn. 1992. But­ter­flies and Skip­pers of Ohio. Colum­bus, OH: Ohio Bi­o­log­i­cal Bul­letin Vol­ume 9 No. 1.

Kop­per, B., R. Charl­ton, D. Mar­golie. 2000. Ovipo­si­tion and site se­lec­tion by the regal frit­il­lary, *Spey­e­ria idalia*, as af­fected by prox­im­ity of vi­o­let host plants. Jour­nal of In­sect Be­hav­ior, 13/5: 651-655.

Kop­per, B., D. Mar­golies, R. Charl­ton. 2002. Life his­tory notes on the regal frit­il­lary, <<Spey­e­ria idalia>> (Drury) (Lep­i­doptera: Nymphal­i­dae), in Kansas tall­grass prairie. Jounal of the Kansas En­to­mo­log­i­cal So­ci­ety, 74/3: 172-177.

Kop­per, B., D. Mar­golies, R. Charl­ton. 2001. Notes on the be­hav­ior of <<Spey­e­ria idalia>> (Drury) (Nymphal­i­dae) lar­vae with im­pli­ca­tions that they are di­ur­nal for­agers. Jour­nal of the Lep­i­dopter­ists' So­ci­ety, 54/3: 96-97.

Kop­per, B., S. Shu, R. Charl­ton, S. Ra­maswamy. 2001. Ev­i­dence for re­pro­duc­tive di­a­pause in the frit­il­lary <<Spey­e­ria idalia>> (Lep­i­dopter: Nymphal­i­dae). An­nals of the En­to­mo­log­i­cal So­ci­ety of Amer­ica, 94/3: 427-432.

May­nard, C. 1891. Man­ual of North Amer­i­can But­ter­flies. Boston MA: De­Wolf, Fiske, and Co.

Miller, J. 1992. The Com­mon Names of North Amer­i­can But­ter­flies. Wash­ing­ton DC: Smith­son­ian In­sti­tu­tion Press.

Miller, L., F. Brown. 1981. Cat­a­logue/Check­list of the But­ter­flies of Amer­ica North of Mex­ico - Mem­oir No. 2 of the Lep­i­dopter­ists' So­ci­ety. Lep­i­dopter­ists' So­ci­ety.

Nielsen, M. 1999. Michi­gan But­ter­flies and Skip­pers: A Field Guide and Ref­er­ence. East Lans­ing, MI: Michi­gan State Uni­ver­sity Ex­ten­sion.

Opler, P., G. Krizek. 1984. But­ter­flies East of the Great Plains: An Il­lus­trated Nat­ural His­tory. John Hop­kins Uni­ver­sity Press.

Pyle, M. 1995. Na­tional Audubon So­ci­ety Field Guide to North Amer­i­can But­ter­flies. NY: Al­fred A Knopf.

Scott, J. 1986. But­ter­flies of North Amer­ica: A Nat­ural His­tory and Field Guide. Stan­ford, CA: Stan­ford Uni­ver­sity Press.

Singer, M., D. Vasco, C. Parme­san, C. Thomas, D. Ng. 1992. Dis­tin­guish­ing be­tween 'pref­er­ence' and 'mo­ti­va­tion' in food choice: An ex­am­ple from in­sect ovipo­si­tion. An­i­mal Be­hav­ior, 44: 463-471.

Struttman, J. "But­ter­flies of New Jer­sey: Regal Frit­il­lary" (On-line ). But­ter­flies of North Amer­ica. Ac­cessed 02/18/03 at http://​www.​npwrc.​usgs.​gov/​resource/​distr/​lepid/​bflyusa/​usa/​80.​htm.

Swen­gel, A. 1996. Ef­fects of fire and hay man­age­ment on abun­dance of prairie but­ter­flies. Bi­o­log­i­cal Con­ser­va­tion, 76: 73-85.

Swen­gel, A., S. Swen­gel. "The Tall-grass Prairie But­ter­fly Com­mu­nity" (On-line ). Ac­cessed 02/18/03 at http://​biology.​usgs.​gov/​s+t/​noframe/​f071.​htm.

Wag­ner, D., M. Wal­lace, J. Boet­tner, J. Elk­in­ton. 1997. Sta­tus up­date and life his­tory stud­ies on the regal frit­il­lary (Lep­i­doptera: Nymphal­i­dae) in Ecol­ogy and Con­ser­va­tion of Grass­lands and Heath­lands of North­east­ern North Amer­ica. Lin­coln: Mass­a­chu­setts Audubon.

Weed, C. 1926. But­ter­flies. Dou­ble­day, Page, and Com­pany.

Williams, B. 2002. Con­ser­va­tion, ge­net­ics, ex­tinc­tion, and tax­o­nomic sta­tus: a case his­tory of the regal frit­il­lary. Con­ser­va­tion Bi­ol­ogy, 16/1: 148-157.

Williams, B. "Evo­lu­tion­ary/Con­ser­va­tion Ge­net­ics of the Regal Frit­il­lary <<Spey­e­ria idalia>>" (On-line ). Ac­cessed 02/18/03 at http://​www.​life.​uiuc.​edu/​paige/​williams/​idalia.​html.

Williams, B. "Regal Frit­il­lar­ies in a Tail­spin" (On-line ). North Amer­i­can But­ter­fly As­so­ci­a­tion. Ac­cessed 01/28/03 at http://​www.​naba.​org/​chapters/​nabasep/​99_​W_​article.​HTM.