BULLETIN OF THE ALLYN MUSEUM
THE ALLYN MUSEUM OF ENTOMOLOGY
Number 10 10 May 1973
STUDIES ON NORTH AMERICAN PHILOTES
I. Roosting behavior, tending ants, parasites, and predators
Department of Entomology, University of California, Davis, Calif. 95616
The following observations are from my notes in connection with field work
on western North American Philotes. This is the first of a series of papers to be
published on the genus. All the identifications are done by viewing the male genitalia
after soaking overnight in a dilute KOH solution and stripped with watchmakers
forceps of surrounding non-chitinous material under the dissecting scope. The
whole genitalia is stored in a plastic shell vial filled with glycerine and pinned to
the specimen, along with the determination label. James L. Reveal of the University
of Maryland kindly made the Eriogonum identifications (foodplant data to be fully
documented and published later). I wish to thank the Allyn Museum of Entomology
for largely sponsoring the extensive field work involved in this project, and John
Burns of Harvard for additional funds from collecting Colias samples for esterase
experiments. Other sources of financial aid came from Theodore J. Cohn, Charles
L. Remington, Lloyd Martin, Charles Hogue, Roy Snelling, and Julian Donahue.
Collector abbreviations: CH = Chris Henne, OS = Oakley Shields, JFE = John
F. Emmel, SLE = Scott Ellis, MT = Mike Toliver, SKD = Stanley Dvorak, RW = Ralph
Wells, JB = James Brock. The roosting behavior records are as follows:
(1) July 14, 1969, ca. 5-6 road mi. WSW of Calif.-Nevada border along Calif.
State Hwy. 167, 6700', T.3N., R.28E., Mono Co., Calif., leg. JFE & OS. 14 Philotes
rita ssp. (clinal between pallescens and elvirae), from 3:30-4:30 pm PST, mostly
settled on plants in a head-down position, on Eriogonum kearneyi var. kearneyi;
some 65 collected flitting and settling in the upper parts of sage bushes.
(2) August 21, 1969, 10 road mi. S. of junction hwy. 53 & 216, along hiway 53,
Duchesne Co., Utah, leg. JFE & OS. Collected from 6:00-6:45 pm MST, sun down,
twilight. Located roosting P. battoides ssp. (new), 13, perched on uppermost part
of Artemisia and Chrysothamnus bushes in gullies dissecting a ridge where
E. corymbosum var. corymbosum plentiful. When disturbed, they flew out. Several
bushes with five to six Philotes, each. Same locality, Aug. 22nd, early morning, air
humid, cool, mackeral sky. From 6:30-7:10 am MST, collected 32 P. battoides, nearly
all perched head-down along upper stems (at tips of dried branches) of a small sage
(one plant with six but most with two or one), facing either N. or S. with wings shut
(6:30-7:00). At 7:00-7:10, the sun broke through and some specimens perched
horizontally; when these were approached, they took flight, whereas the 6:30-7:00
individuals were mostly torpid except a few which dropped into these bushes when
disturbed. Mostly in small gullies, but some scattered over the slope.
(3) August 24, 1969, 8 road mi. NW past turnoff to Dugout Ranch, along road to
Canyonlands Nat. Park, via Indian Creek State Park, San Juan Co., Utah, leg.
JFE & OS. Collected from 5:40-6:10 pm MST, took 13 P. rita ssp. (new) around E.
leptocladon var. leptocladon blooms, mostly 68 seeking roosting sites (flew around
vegetation, mostly other than Eriogonum, and sat head-down).
(4) August 26, 1969, summit of road to 1'/2 mi. E., of Little Flat Top, 5500', T.26S.,
R.13E., ca. 10-11 mi. SE of Utah hiway 24, Emery Co., Utah, leg. JFE & OS. In
the late afternoon, many P. rita ssp. (new) noted hanging up for night, ventral side
toward the W., head-down, in plants mostly other than Eriogonum smithiii and
leptocladon), especially sage, mostly on E. side of plants.
(5) September 20, 1969, South Fork of Big Rock Creek, 4500', San Gabriel Mts.,
Los Angeles Co., Calif., leg. JFE, OS, CH. Found four 9, one S P. enoptes near
enoptes sitting on flower-heads of E. nudum var. pauciflorum between 2:30-3:00
pm PST, canyon mostly in shadow. Eriogonum common in wash just above camp-
ground. Henne said these usually roost on flower-heads of the Eriogonum; all
these taken were doing so and flip-flopped about or sat in the net after being netted,
indicating they were lethargic.
(6) June 28, 1970, 12.1 road mi. E. of junction hiway 33 & 150, 6.1 road mi. NW of
junction Hwy. 150 & 126 (N. of Santa Paula along Hwy. 150), Ventura Co., Calif.,
leg. SKD & OS. Took a few P. enoptes ssp. (somewhat intermediate between smith
and tildeni) roosting on Eriogonum parvifolium var. paynei. Very little sun left. One
Eriogonum with flowers still in bud, along the creek, had seven adults roosting
on terminal branches in a cluster, all oriented to the N. with their broadsides to
the sun, just catching the sun's rays, 5:00-5:30 pm PST.
(7) July 3, 1970, 3 road mi. SSE of Hull Mtn. Lookout, along Boardman Ridge,
Mendocino Nat. For., Lake-Glenn Co. line, Calif., leg. SKD & OS. One S, one 9
P. enoptes ssp. (near enoptes) sitting perpendicular to the sun's rays (sun below
horizon) on flower-heads of E. nudum var. nudum at 7:05 pm PST.
(8) August 9, 1970, hillside ca. 1 mi. W. of Park Point Fire Lookout, Mesa Verde
Nat. Park, Montezuma Co., Colo., leg. SLE & OS. Noted one P. rita spaldingi
[new combination] perched head-down on a bloom of E. racemosum, apparently
for the night, in late afternoon.
(9) August 17, 1970, 10.8 road mi. NE of Cerrillos, along Hwy. 10, Santa Fe Co., New
Mexico, leg. SLE & OS. One 6, one 9 P. rita (clinal between rita rita and r. coloradensis)
on E. effusum var. effusum, sitting torpid on the blooms, 8:15-8:30 am MST.
(10) August 18,1970,8.0 road mi. SW of junction Hwy. 197 & 44 (SW of Cuba), along
Hwy. 197, Sandoval Co., N.M., leg. SLE & OS. Collected from ca. 3:30-4:15 pm MST,
took six P. rita (clinal between rita rita and r. coloradensis) alighting on E. effusum
var. effusum mostly, for the night. A few on sage bushes along the road shoulder,
especially between 4:00-4:15-33 flying rapidly around sage along the hwy., probably
seeking roost sites for the night. Also noted nine $ Phyciodes campestris perched
on one sage bush right nest to the hwy., at 4:15.
(11) August 19, 1970, 2.0 road mi. SW of junction of Hwy. 44 & 85, along Hwy. 85
(SW of Bernalillo), Sandoval Co., N.M., leg. SLE, OS, MT. Along the highway, found
eight P. rita (clinal between rita rita and r. coloradensis) roosting on E. effusum var.
effusum in gullies, from 5:20-5:40 pm MST.
(12) August 25, 1970, ca. 13-14 road mi. NE of Lordsburg, along Hwy. 90, Hidalgo
Co., N.M., leg. SLE, OS, MT. Collected from 6:00-7:00 pm MST along road shoulder
where the annual E. polycladon grew in dense stands in disturbed soil. Took 53
P. rita rita roosting, mostly on this Eriogonum. Roosting specimens perched
with wing tips into the sun and at right angles to the sun's rays and could easily be
spotted against the Eriogonum. Three rita specimens were taken roosting on
E. wrightii var. wrightii plants along a gully.
(13) September 1, 1970, 7.7 to 8.1 road mi. ENE of Kayenta (from junction of Hwy.
464 & 164), Navajo Co., Arizona, leg. SLE & OS. Collected from ca. 6:15-7:30 pm
MST, four 3 P. battoides ssp. (new) roosting on bushes in gully within a pure stand
of E. corymbosum var. velutinum. One 9 battoides roosting on a mint, with
corymbosum (rare) and leptocladon (common) in the area. Also three P. rita ssp.
(new) roosting head-down in E. leptocladon var. ramosissimum in areas where no
corymbosum. One 9 rita roosting on an Ephedra sp. where leptocladon was common
and corymbosum scarce. One 3 rita found roosting on a leptocladon bush (6:35)
in an area of leptocladon and corymbosum in a mixed stand.
(14) September 4, 1970, 1.5 road mi. SE of junction of Hwy. 128 & road to Castleton,
along road to Castleton, Grand Co., Utah, leg. SLE & OS. Took five P. battoides
ssp. (new) roosting on E. corymbosum var. orbiculatum plants or on Atriplex sp. in
wash bottom during cool, overcast weather, midday.
(15) June 20, 1971, S. end of Stillwater Range, along Hwy. 50, 28-29 road mi. SE of
Fallon, Churchill Co., Nev., leg. JB, OS, RW. In a dry wash a few P. battoides ssp.
(near martini and bernardino) roosting on E. heermannii var. humilius in early am,
bright, clear, calm, warm day. One 3 was sitting on heermannii at 7:40 am PST,
upper terminal branch on sun side of plant at the wash edge next to a hill with lots of
heermanni scattered, mostly not in bloom. One 9 roosted on a bush next to a
heermannii (in a spot only just out of shadow). At 8:20 am PST tapped a fresh male
P. speciosa from a heermannii plant in a draw with Oxytheca perfoliata plants
fairly nearby. Area had recent rains and many annuals out. Same locality, July
3rd, found two worn 3 battoides sitting head-down on terminal branch ends of small
heermannii plants between 8:15-8:30 am PST. When one was disturbed, it flew
about sluggishly and perched up on vegetation at the upper end 6-8X, as they do when
choosing the night roost (very skittish). Also, one worn 9 was flitting about and
perching up at 9:00 am in the mouth of the draw where there was much sun (it seemed
not yet "fully lightlyy".
(16) June 27, 1971, South Fork of Silver Creek, ca. 1 mi. E. (upstream) of Chicken
Hawk Spring, ca 4 mi. W. of Ice House Store, 5000', El Dorado Co., Calif., leg. OS &
RW. Coolish, partly cloudy. Nine 9, 12 3 P. enoptes enoptes (missed two others)
sitting on terminal branches of E. nudum var. deductum (almost all head-down, two
or three head-up, all with wings tightly closed together and feet firmly grasping buds,
perpendicular and broadside to the sun's rays, along roadside, between 9:05-10:07
am PST (only one was definitely on wing, though not fully active, at 10:12). Several
flipped about lethargically in the net after capture, one started to fly when
approached. Nearly all were fresh. Perhaps these enoptes withstood the major storm
with heavy downpours yesterday, in this roost position. One 9 roosting on a
Ceanothus tip next to nudum at 9:05 am PST.
The only report of possible tending ants on Philotes larvae I have been able
to find is that of Opler (1968) for Iridomyrmex humilis Mayr on Philotes enoptes
bayensis. However, he states that the relationship may have been fortuitous since
they were only observed in close proximity to each other and not in direct contact.
Below are some records obtained during the course of field work on the genus
Philotes. All were collected by John F. Emmel and O. Shields unless otherwise noted.
Roy R. Snelling identified the ant species and the coccinellids; these are deposited
at the Los Angeles County Museum (Natural History). (According to Snelling, ants
are best preserved in 70-75% ethanol.) The Philotes material is currently in the
Shields' Study Collection, later to go to the Allyn Museum Collection.
The tending ant records are as follows:
(1) May 6, 1969, vicinity of Briceburg, Mariposa Co., Calif., leg. N. La Due & 0.
Shields. Numerous Philotes sonorensis larvae (ca. 50) were found mining the
succulent leaves of Dudleya cymosa, ranging from second to fifth instars. Tending
ants, Tapinoma sessile (Say), were commonly crawling over Dudleya plants and
on the larger larvae inside the leaves. Newcomer (1912) implied that certain species
such as Philotes sonorensis that feed within thick leaves may not be tended by ants,
but these observations do not support this.
(2) July 8, 1969, 5 road mi. W. of Five Mile Spring, on U.S. Hwy. 6, 6400', at S. end
of Monitor Range, NW /4 of T.3N., R.47E., Nye Co., Nevada. Many larvae of Philotes
enoptes near ancilla (none reared successfully, but this is the common species on
E. umbellatum to the north in the Toiyabe Range) were taken on flowers of Eriogonum
umbellatum var. umbellatum. Two species of ants, Crematogaster mormonum
Emery and Formica neogagates Emery, were helpful in locating larvae on the
plants. These ants also attended aphids and mealy bugs on the flowers. The tending
ants "stroked" the larvae with their antennae and kept returning to the larvae.
(3) July 14, 1969, Cottonwood Canyon, 7300', S. of Bodie, Mono Co., Calif. Many
Philotes battoides glaucon larvae (ca. 25-30), third to fifth instar, taken on flowers of
E. umbellatum var. umbellatum, with a small black ant, Tapinoma sessile (Say),
"tending" the larvae (antennal stroking, walking over larva). No adults reared,
but P. b. glaucon flies abundantly here on the umbellatum about a month earlier.
(4) July 29, 1969, sand dunes 1 miles S. of Blind Spring, 5800', SE end of Baking
Powder Flat, W. of Snake Range, T.11N., R.67E., White Pine Co., Nevada. Eight
Philotes battoides ssp. (new) larvae found on Eriogonum shockleyi ssp. longilobum
flowers; all were fifth instar although unusually small for Philotes. Three tending
ants, Formica obtusopilosa Emery, were noted; these ants also commonly fed on
the flowers. One adult Philotes male was dissected from the pupa and genitalically
(5) August 2,1969, NW corner of T.9N., R.58E., sand flats, 7 road mi. S. of Current,
5000', on dirt road to Nyala, Railroad Valley, NE corner of Nye Co., Nevada. Many
Philotes rita pallescens larvae collected on Eriogonum kearneyi var. kearneyi
flowers, ca. third to fifth instars, initially found by watching the tending ants!
Three species of ants were involved, Dorymyrmex pyramicus (Roger), Camponotus
nearcticus Emery, and Myrmecocystus kennedyi Cole. These ants walked up and
down the Eriogonum stems and also fed in the flowers (only one mealy bug and one
aphid colony noted). The ants tended even the small rita larvae. Adult rita were
common here on this date and about a month earlier, and several were reared from
(6) September 8, 1969, corner of Binder & Whiting Streets, El Segundo, Los Angeles
Co., Calif. Larvae of Philotes battoides ssp. (new) on flowers of Eriogonum
parvifolium var. parvifolium were commonly tended by Iridomyrmex humilis
(Andre). Several adult Philotes reared.
A parasite was obtained from Philotes sonorensis larvae and determined by
E. E. Grissell, UC Davis, as Euderus, a species near lividus (Ashmead) (Hymenoptera:
Eulophidae). Nine specimens were obtained, three are with K. Yoshimoto (Canadian
Dept. Agr.), and six are in the UC Davis entomology collection. The localities were:
Briceburg, Mariposa Co., Calif., from larvae of sonorensis collected on May 6,
1969; parasites emerged from a 4th instar sonorensis larva on May 7 and pupated
ca. May 10; another batch emerged from a shriveled larva on ca. May 14. 4 mi. N.
of Placerville, South Fork of American River, on road to Georgetown, El Dorado Co.,
Calif., larvae of sonorensis collected May 4, 1969, leg. R. F. Denno & O. Shields;
parasite ex dead sonsorensis larva, noted as pupa on May 14, noted as adult on May
25, one specimen. "The biological records of the Nearctic Euderus indicate that most
species are host specific on pupae of leaf tying, leaf mining, twig and fruit boring
Lepidoptera, stem boring Coleoptera, and gall making Hymenoptera. Others
show hyperparasitism on other Hymenoptera and have a diversity in host
preference" (Yoshimoto, 1971: 542).
Rarely adult Philotes have square chips out of the wing edge, sometimes on both
sides, or a line across the wing with no scales (in line with a chip), perhaps in-
dicative of bird and/or lizard predation. Old wings of a Philotes enoptes near ancilla
were found in a spider web on Eriogonum umbellatum var. umbellatum, July 11,
1969, south & west facing slopes of Victorine Canyon, 8000-10,000', S. side of Bunker
Hill, Toiyabe Range, Lander Co., Nevada. On February 20, 1972, ca. 3 mi. NE of
Auburn, Placer Co., Calif., leg. 0. Shields, J. Mori, S. Sims, & R. Wells, we found a
sonorensis adult caught in a small web by the tip of the wing. It fluttered for about
two hours before finally breaking loose, then sat resting on a weed head for 15
minutes. The spider in the web was an orb weaver, Cyclosa sp. (Araneidae),
determined by L. Vincent and K. Yeargan, UC Davis. One 9 P. enoptes dammersi
was found floating on the surface of a small pool, September 10, 1969, / mi. S. of
Cove Spring, Granite Mts., SW of Providence Mts., San Bernardino Co., Calif. On
August 8, 1969, W. end of Dana Plateau, above Tioga Pass, 11,000-11,400', Mono
Co., Calif., a dead Philotes battoides battoides female was dragged across the ground
by an ant, Formica sp., fusca group. (Snelling's notes say, "Specimen is broken and
I cannot give a name with certainty. Seems nearest F. fusca Linne.") A possible
predator of the P. rita pallescens larvae from the Aug. 2, 1969, Currant, Nevada,
locality are two species of coccinellids, Hippodamia convergens Guerin and H.
quinquesignata Kirby; a few larvae and adults of these beetles were noticed crawling
over the Eriogonum kearneyi stems.
Newcomer, E. J., 1912. Some observations on the relations of ants and lycaenid
caterpillars, and a description of the relational organs of the latter. J. N. Y. Ent.
Soc., 20: 31-36.
Opler, P. A., 1968. Myrmecophily reported for Icaricia acmon and Philotes enoptes
bayensis (Lycaenidae, Lepidoptera). Pan-Pac. Ent., 44: 79-80.
Yoshimoto, C. M., 1971. Revision of the genus Euderus of America north of Mexico
(Hymenoptera: Eulophidae). Canad. Ent., 103: 541-578.