Glendora Natural History Website Data Compiled by Dick Swinney
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Dick Swinney

copyright March 1989

Revised March 1993 and October 2007

All specimens collected and or observed by the author and E. R. Hulbirt unless otherwise stated.

Identification by Dick Swinney and E. R. Hulbirt

This list has been made from specimens collected in Big Dalton Canyon by E. R. Hulbirt, Phd, and those collected by the author within the Glendora City Limits. Dr. Hulbirt’s list represents butterflies collected from 1929 to 1949 while the author’s list represents specimens collected from 1954 to 2007. Hulbirt’s earliest collections may represent specimens at the location of the Big Dalton Dam before its construction. Dr. Hulbirt’s list of butterflies of Big Dalton Canyon was submitted to H. Paul Keiser on July 21, 1949. Unfortunately, Hulbirt’s list does not include abundance information. Mr. Keiser was the caretaker of the Big Dalton Dam at that time and was interested in collecting as much material as possible of the natural history and local historical information of Glendora and specifically Big Dalton Canyon. He was avidly pursuing this interest until the time of his death.

Paul sent a copy of Hulbirt’s list to J.D. Sinclair, Forester, U.S. Department of Agriculture, Forest Service, California Forest and Range Experiment Station. Mr. Sinclair acknowledged receipt of Hulbirt’s list on August 10, 1949. Mr. Sinclair stated he would keep it for further reference. Dr. Hulbirt’s original list was written using the scientific and common names in accordance with John A Constock’s book, Butterflies of California. Hulbirt’s list referenced in the first edition of this paper reflected changes in nomenclature according to the latest work of California butterflies by John S. Garth and J.W. Tilden, California Butterflies, 1986. The scientific and common names used in this edition, follow the NABA Checklist and English Names of North American Butterflies, 1995. NABA web site: The subspecies (ssp.) used in the first edition of Butterflies of Glendora are listed here for reference. These taxa are no longer officially recognized, but represent species variations which were used by entomologists in the past.

Hulbirt most likely included specimens collected above Big Dalton Dam in the north east area of the canyon near the junction with Bell Canyon, as well as Monroe Canyon north of Big Dalton Dam. All specimens collected by the author were taken from below the Dam. Dr. Hulbirt’s collection was given to Citrus Junior College after his death and was later donated by the college to the Los Angeles Natural History Museum. The author’s collection remains at his residence.

+ Specimens collected by Dick Swinney but not by Dr. Hulbirt

* Specimens collected by Dr. Hulbirt but not by Dick Swinney

A number of species collected by Dr. Hulbirt prior to 1949 have not been observed in recent years. There are several possibilities which may explain the apparent disappearance of these butterfly species:

1. The urban development of the surrounding area has possibly destroyed populations of host plants of specific butterflies. Some butterflies apparently feed only on one species of plant.

2. The change in air quality in the Los Angeles Basin. This has reportedly caused the decline of Eurema necippe and Papilio zelicaon in our area since the food plants of both species are still present.

3. The introduction of pesticides and herbicides in the surrounding area.

4. Dr. Hulbirt collected in the extreme northern area of BDC which Mr. Swinney did infrequently.

Last updated: June 5, 2012


Cercyonis sthenele Woodland Satyr

One specimen collected by author in an orange grove at Sierra Madre Avenue and Pennsylvania Ave. in June of 1959. One specimen observed by Dick Swinney at Tanbark Flats in the San Dimas Experimental Forest on 8/30/1989. This is to the N.E. of the city boundary.

Thessalia leanira wrighti Leanira Checkerspot

One specimen collected in Glendora near 1954 by author.

Papilio zelicaon Anis Swallowtail

Commonly collected in Glendora until late 1980’s but rairly observed in the N. foothills.

Phoebis sennae Cloudless Sulphur

Several specimens observed in BDC during the week of May 3, 1992 by the author. Several specimens of both sexes collected within city boundaries during that same week by author.

Many specimens observed from September 2008 through January 2009. Ten or more could be seen at one time at Cassia shrubs in bloom. Migration very significant.

Nymphalis californica California Tortoise Shell

Observed at 2 locations in BDC on March 8, 1993: BDD (west side) and Pavil Canyon & BDC jnct. One specimen on video tape, not collected.

Atlides halesus Great Purple Hairstreak

One was seen on Senecio flaccidus var. douglasii near BDDB parking area in the fall of 1991. Several collected within city boundaries by author in the 1950’s.

Phyciodes melitta Field Crescent

One collected in the BDWP by Dr. Hulbirt. One specimen was observed by Dick Swinney in BDC, FCT, specimen was collected, but it escaped, date uncertain - late 1970’s.

Family Papilionidae: Swallowtails

Subfamily Papilioninae: Swallowtails

Papilio zelicaon Anise Swallowtail

Rare, 1 emerged 7/31/1967, pupated 7/22/1967, at N. Vermont; 1 emerged 8/1/1967, pupated 7/23/1967, N. Vermont; 1 emerged 8/2/1967, pupated 7/24/1967, at N. Vermont; 1 emerged 8/4/1967, pupated 7/24/1967, N. Vermont; 1 emerged 8/5/1967, pupated on 7/25/1967, at N. Vermont, host plant Phoeniculum vulgare; last observed in Glendora approx. 1990

Papilio cresphontes Giant Swallowtail

Uncommon in residential areas, first observed by author in Glendora in Aug. 2000 at N. Vermont Ave. on flowers of Eucalyptus; second observation in June, 2002 at N. Vermont on citrus; 1 on 8/9/02 at N. Vermont on citrus; 1 on 9/16/02 at N. Vermont on citrus; 1 on 7/14/2003 N. Vermont on citrus; 1 on 8/19/2003 at N. Vermont, specimen retained in author’s collection.

The number of sightings each year since 2003 has significantly increased. During Aug. & Sep., of 2007, nearly 1 individual each week was recorded by the author near citrus at the N. Vermont location.

Papilio rutulus Western Tiger Swallowtail

Common throughout, as common in residential areas as they are in foothills

1986-1988, July, August, observed from Apr -Sep.

Papilio eurymedon Pale Swallowtail

Common, generally more abundant in the foothill areas, especially in the BDC & LDC, often observed at high points (commonly referred to as “hilltopping”)

1986-1988, April-June, August

Family Pieridae: Whites and Sulphurs

Subfamily Coliadinae: Sulphurs (Sulphurs)

Colias Alexandra

ssp. harfordii Queen Alexandra’s Sulphur

Rare, 1 on 8/8/1963 in BDC; 1 in June, 1965 in Glendora; 1 on 8/14/1965 in BDC; 1 on 6/26/1986 in BDC; 1 on 4/9/1987 in BDC;

Colias eurytheme Orange Sulphur(alfalfa butterfly)

Abundant throughout

Fairly Common, 1963-1986, Apr.-Sep., observed Oct.-Dec.

3 forms recognized in the first edition: ariadne, amphidusa and autumnalis

Colias eurydice California Dogface

Common, most common in the N. foothils near its food source, Amorpha californica, this is our California State Butterfly

1959-1992, July, Aug., Nov., observed July-Dec.

2 forms recognized in the first edition: bernardino and amorphae

+Phoebis sennae Cloudless Sulphur

formerly ssp. marcellina

Rare, migratorial, 3 from Apr. 13-20, 1992 at N. Vermont during migration, approx. 24 sulphurs per hour passed through the 600 block of N. Vermont from 9:30 am to 4:00 pm from Apr. 13-20, 1992; 1on 2/25/2002, at N. Vermont Ave., 1 on 2/26/2002 at Easly Cnyn. Dr.; commonly seen throughout Glendora from Sept. 2008 through Jan. 2009.

Eurema nicippe Sleepy Orange

Rare, 1 on 9/8/1963 on Senna sp. in alley in 600 block of N. Glendora Ave.; 1 observed on 7/5/1988 at BDC, FCT

+Nathalis iole Dainty Sulphur

Rare, 1 on 8/4/1986 in Glendora; 2 on 8/16/1986 in Glendora; 1 on 7/5/1988 at BDDB; 1 on 6/14/1988 at San Dimas Cnyn.;

Most likely to be found in BDC & upper field of Saint Lucy’s High School and the adjoining Church of the Open Door property

Subfamily Pierinae: Whites

Anthocaris sara Sara Orangetip

Abundant in the foothills, 1962-1989, Feb-Apr.

Second generation specimens are often produced during years of heavy rainfall, 3 on 7/15/1967 in BDC

*Anthocaris lanceolata California White Tip


Pieris rapae Cabbage Butterfly

Abundant throughout, 4 on 7/16/1967, all year

Pontia protodice Checkered White

Common in N. foothills, 1965-1987, Apr., June, July, Sep., observed Aug., Oct., Nov.

Family Lycaenidae: Gossamer-wing Butterflies

Subfamily Lycaeninae: Coppers

Lycaena arota Tailed Copper

formerly ssp. nubila

Abundant, 1967-1986, June, July, Aug.

*Lycaena gorgon Gorgon Copper


Subfamily: Theclinae Hairstreaks

Habrodais grunus Golden Hairstreak

formerly ssp. grunus

Rare, Collected by Hulbirt within Glendora, collected by author on 8/14/1986 in Santa Anita Cnyn. & on 8/11/1986 at 2 mi. W of Mt. Baldy Village on GRR, confined to higher elevations where Canyon Live Oak (host plant) is found

Atlides Halesus Great Purple Hairstreak

formerly ssp. estesi

Rare, commonly collected by author between 1954-1958 throughout Glendora, fairly common on grounds of Roosevelt Elementary School during that time, 1 during Apr. 13-20, 1992 at N. Vermont on lawn; no observations since 1992

Satyrium californica California Hairstreak

Status uncertain

Satyrium sylvinus Sylvan Hairstreak

formerly ssp. sylvinus

Rare, 1 on 6/21/1986 at BDC, 3 on 6/7/1987 at BDC

Satyrium tetra Mountain Mahogany Hairstreak

Rare, 1 in July, 1963 in BDC; 1 on 7/27/1967 at BDC

Satyrium saepium Hedgerow Hairstreak

formerly ssp. saepium

Rare, 1 on 7/5/1988 at BDC, FCT

Callophrys dumetorum

dumetorum Bramble Hairstreak

listed as ssp. perplexa by Hulbirt

Fairly Common, 1 on 4/6/1972 at BDC; 1 on 4/13,19,20/1987 at BDC, FCT; 1 on 4/24/1987 at BDC

Callophrys augustinus Brown Elfin

formerly ssp. iroides

Fairly Common, 2 on 5/21/1988 at BDC; 1 on 2/25/1989 at BDC, FCT, on Baccharis salicifolia; 1 on 6/27/1988 at BDC, FCT; 1 on 4/1/1989 at BDC, FCT on Cercis occidentalis (introduced)

Strymon melinus Gray Hairstreak

formerly ssp. pudicus

Fairly Common throughout, 1986-1988, July, Aug.

Subfamily: Polyommatinae Blues

Brephidium exile Western Pygmy-Blue

Uncommon, 1 on 5/24/1988 at San Dimas Cnyn., 0.6 mi. N. of Goldenhills Rd.; 3 on 11/16/1988 at BDC, FCT

Leptotes marina Marine Blue

Abundant, 1967-1986, May-Aug., Oct., Nov.

+Hemiargus isola Reakirt’s Blue

formerly ssp. alce

Celastrina ladon Spring Azure

formerly ssp. echo

Philotes sonorensis Sonoran Blue

Fairly Common in the N. foothills, especially in LDC & BDC drainages, 1964-1987, March, Apr.

Euphilotes battoides

bernardino Bernardino Square-spotted Blue

Fairly Common, 1963-1986, June, July

Glaucopsyche lygdamus Silvery Blue

formerly ssp. australis

Common, 1964-1987, Mar.-May

Plebejus acmon Acmon Blue

formerly spp. acmon and acmon “cottlei”

Abundant, 1967-1989, Feb., Apr.,June-Aug.

Plebejus lupini Lupine Blue

formerly ssp. monticola

Uncommon, 1 on 7/20/1988 at BDC, MG

Family Riodinidae: Melalmarks

Apodemia mormo Mormon Metalmark

formerly ssp. virrgulti

Fairly Common in N. foothills 1968-1988, Apr., May, Aug.-Oct.

Family Nymphalidae: Brush-footed Butterflies

Subfamily Heliconiinae: Heliconians and Fritillaries

+Agraulis vanillae Gulf Fritillary

formerly ssp. incarnata

Abundant, especially in areas where the host plant Passiflora caerulea occurs, will feed on other Passiflora species as well,1965-1986, all year

*Speyeria callippe ssp. Callippe Fritillary

Abundance data from Hulbirt’s collection not available, the closest specimen to Glendora collected by the author was on 8/11/1986 at 2 mi. W. of Mt. Baldy Village on GRR

Subfamily Nymphalinae: True Brush-foots

Thessalia leanira Leanira Checkerspot

formerly ssp. wrighti

Extirpated, present on Hulbirt’s list, 1 near 1954 at N. Vermont by author at 7 years of age, this is the oldest specimen in the author’s collection

Chlosyne gabbii Gabb’s Checkerspot

Rare, BDC, 1 in 6/1963 at BDC; 1 on 4/29/1965, Glendora; 1 on 4/13/1987 at BDC, FCT

2 on 5/14/1988 at BDC, FCT; 1 on 5/21/1988, BDC;

Phyciodes campestris Field Crescent

Possibly extirpated, collected by Hulbirt, 1 in late 1970’s by author in BDC, FCT, collected but specimen escaped, nearest current population known by author is Falling Springs Resort in North Fork of San Gabriel Cnyn., several specimens in author’s collection

Phyciodes mylitta Mylitta Crescent

Common in N. foothills, 1967-1987, Feb., April, June-Sep.

Euphydryas chalcedona Variable Checkerspot

Abundance levels fluctuate dramatically in response to annual rainfall, Rare to Abundant

2 in June, 1963 in Glendora; 2 on 5/7/1987 in BDC; 1 on 6/10/1987 in BDC

June 2001 - Abundant in the N. foothills and common in many residential areas. Common in the 600 block of N. Vermont Ave. Dead specimens commonly found.

Polygonia satyrus Satyr Comma

formerly ssp. neomarsyas

Rare in BDC, Pavil Cnyn, observed 1986-1995

+Nymphalis californica California Tortoiseshell

Rare, 2 observed on 3/8/1993 and videotaped, 1 on W. side of BDD, 1 at jnct. of Pavil & Big Dalton Cnyn’s, usually found above 5,000 ft. in the San Gabriel Mts, especially in Ice House Cnyn.

Nymphalis antiopa Mourning Cloak

Uncommon to Common throughout, 1 on 6/22/1986 in Glendora, observed all months

Vanessa virginiensis American Lady

Abundance varies significantly, this species experiences large migrations from time to time,

Fairly Common to Abundant throughout, all months, 1 on 11/22/1986 in Glendora

Vanessa cardui Painted Lady

Abundance varies, this species experiences large migrations from time to time,

Common to Abundant throughout, all months

Vanessa annabella West Coast Lady

Uncommon throughout, 1 on 4/22/1967 in Glendora; 1 on 4/6/1972 at BDC

Vanessa atalanta Red Admiral

Uncommon throughout, all months, 1 in Aug., 1986 in Glendora; 1 on 11/2/1986 in Glendora

Junonia coenia Common Buckeye

Common in foothills, Uncommon to Fairly Common in residential areas, all months

Subfamily Limenitidinae: Admirals and Relatives

Limenitis lorquini Lorquin’s Admiral

Rare to Uncommon in N. foothill cnyn’s, 1 on 6/27/1987 in San Dimas Cnyn.; 1 on 6/23/1988 in BDC; observed July-Sep. in LDC & BDC

Adelpha bredowii California Sister

formerly ssp. californica

Common in N. foothills, 1986,1987, Apr., Aug., Oct.

Subfamily Satyrinae: Satyrs

Coenonympha tullia

california California Common Ringlet

Fairly Common in N. foothills, 8/10/1967 at BDC; 1 on 4/6/1987 in BDC; 1 on 4/13/1987 at BDC, FCT

Cercyonis sthenele Great Basin Wood-Nymph

formerly ssp. sylvestris

Extirpated, possibly still occurring in farthest N.E. area above 2,000 ft.

Collected by Hulbirt; 1 in June, 1959 by author in citrus grove at S.W. jnct. of Sierra Madre Ave. & Pennsylvania Ave., area is now residential

Subfamily Danainae: Monarchs

Danaus plexippus Monarch

Uncommon to Fairly Common throughout, all months

Danaus gilippus Queen

formerly ssp. strigosus

Rare to Fairly Common, 1 on 8/4/1986 in Glendora; 1 on 9/3,5/1988 at BDC; most often observed in BDC during Aug. - Oct.; 1 on 4/28/08 at jnct. of Pavil & Big Dalton Canyon

Family Hesperiidae: Skippers

Subfamily Pyrginae: Spread-wing Skippers

*Thorybes pylades Northern Cloudywing

Erynnis propertius Propertius Duskywing

Rare in N. foothills, 1 on 7/27/1967 at BDC;

Erynnis tristis Mournful Duskywing

Fairly Common in N. foothills, 1 on 6/21/1986 at BDC; 1 on 8/8/1986 at BDC; 1 on 6/23/1988 at BDC; 1 on 3/13/1989, San Dimas Cnyn.; 1 on 9/7/1991 at BDDB

Erynnis funeralis Funereal Duskywing

Pyrgus albescens White Checkered-Skipper

Common in N. foothills, 1 on 4/6/1972 in Glendora;

*Heliopetes ericetorum Northern White-Skipper

Subfamily Hesperiinae: Grass Skippers

*Copaeodes aurantiacus Orange Skipperling

Hylephila phyleus Fiery Skipper

Abundant throughout, all months, 1986

Polites sabuleti Sandhill Skipper

1 on 8/11/1967 at BDC; 1 on 9/22/1988, BDC; 1 on 8/27/1988 at BDC, FCT;

Atalopedes campestris Sachem

Uncommon, 1 on 7/5/1988 at BDDB;

Ochlodes sylvanoides Woodland Skipper

Uncommon, 2 on 7/5/1988 at BDDB & BDC, FCT; 1 on 7/20/1988 at BDC, FCT; 1 on 8/31/1988 at BDDB;

Ochlodes agricola Rural Skipper

Uncommon, 1 on 5/21/1988 at BDC; 2 on 8/22/1988 at BDC, FCT;

+Poanes melane Umber Skipper

Fairly Common in N. foothills, 1on 9/3/1986 at BDC; 1 on 5/7/1987 in BDC; 1 on 7/5/1987 at BDC; 1 on 8/22/1988 at BDDB

*Lerodea eufala Eufala Skipper

Butterflies Collected by E.R. Hulbirt

This list is presented here exactly as it was presented to Paul Keiser on 7/21/1949. The provision of Hulbirt’s original list may be useful to some in verifying the proper identity of his specimens. The order of listed specimens occurs just as he presented them.

Papilio eurymedon Pale Swallowtail

Papilio rutulus Western Tiger Swallowtail

Papilio Zelicaon Anise Swallowtail

Pieris protodice Common White

Pieris protodice vernalie Vernal White

Pieris raphae Cabbage Butterfly

Anthocharis lanceolata australis Grinnell’s Marble

Anthocharis sara reakirti Reakirt’s Orange Tip

Zerene eurydice California Dog Face

Zerene eurydice bernardino Margined Dog Face

Zerene eurydice amorphae Clouded Dog Face

Eurymus eurytheme Boisduval’s Sulphur

Eurymus eurytheme amphidusa Flavid Sulphur

Eurymus harfordi Harford’s Sulphur

Eurema nicippe Nicippe Yellow

Danaus archippus Monarch

Danaus berenice strigosa Striated Queen

Coenonympha california California Ringlet

Coenonympha california galactinus Boisduval’s Ringlet

Cercyonis silvestris Sylvan Satyr

Argynnis callippe Callippe Fritillary

Euphydryas chalcedona Chalcedon Checker Spot

Melitaea gabbi Gabb’s Checker Spot

Melitaea leanira wrighti Wright’s Checker Spot

Phyciodes mylitta Mylitta Crescent

Phyciodes campestris Field Crescent

Polygonia satyrus Satyr

Aglais antiopa Mourning Cloak

Junonia coenia Buckeye

Vanessa cardui Painted Lady

Vanessa carye West Coast Lady

Vanessa virginiensis Virginia Lady

Vanessa atlanta Alderman’s Butterfly

Basilarchia lorquini Lorquin’s Admiral

Heterochroa bredowi californica California Sister

Apodemia mormo vigulti Behr’s Metal Mark

Habrodais grunus Boisduval’s Hair Streak

Strymon melinus Common Hair Streak

Strymon californica California Hair Streak

Strymon sylvinus Sylvan Hair Streak

Strymon saepium Hedge Row Hair Streak

Strymon adenostomatis Grey Hair Streak

Callophrys dumetorum perplexa Perplexing Hair Streak

Incisalia iroides Western Elfin

Tharsalea arota nubila Cloudy Copper

Heodes gorgon Gorgon Copper

Leptotes marina Marine Blue

Brephidium exilis Pygmy Blue

Plebejus acmon Acmon Blue

Plebejus acmon cottlei Cottle’s Blue

Plebejus acmon monticola Clemence’s Blue

Philotes battoides bernardino San Bernardino Blue

Philotes sonorensis Sonora Blue

Glaucopsyche lygdamus australis Southern Blue

Lycaenoposis psuedargiolus echo Echo Blue

Urbanus tessellata occidentalis Western Checkered Skipper

Urbanus ericetorum Large White Skipper

Thorybes pylades Northern Dusky Wing

Erynnis propertius Propertius’ Dusky Wing

Erynnis funeralis Funeral Dusky Wing

Erynnis tristis Mournful Dusky Wing

Copaeodes aurantiaca Hewitson’s Skipper

Hylephila phylaeus Fiery Skipper

Ochlodes agricola Rural Skipper

Ochlodes sylvanoides Woodland Skipper

Polites sabuleti Sandhill Skipper

Atalopetes capestris Field Skipper

Lerodea eufala Eufala Skipper

Atlides halesus Great Purple Hair Streak

Permission is freely granted to replroduce any or all of this material as long as full credit is given to the author at