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Subspecies Hyalophora columbia gloveri - Glover's Silkmoth - Hodges#7769

Columbia Silk Moth - Hyalophora columbia Hyalophora gloveri - Hyalophora columbia - male Vapour light - Hyalophora columbia Hyalophora gloveri - Hyalophora columbia - male moth, BIG, pretty - Hyalophora columbia moth, BIG, pretty - Hyalophora columbia Hyalophora gloveri, larva - Hyalophora columbia Larva Day 14 - Hyalophora columbia
Show images of: caterpillars · adults · both
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Bombycoidea (Silkworm, Sphinx, and Royal Moths)
Family Saturniidae (Giant Silkworm and Royal Moths)
Subfamily Saturniinae (Silkmoths)
Tribe Attacini
Genus Hyalophora
Species columbia (Columbia Silkmoth - Hodges#7768)
Subspecies gloveri (Glover's Silkmoth - Hodges#7769)
Synonyms and other taxonomic changes
Was formerly considered separate species, Hyalophora gloveri, but now considered a subspecies of Hyalophora columbia.

Recently there has been some evidence and support to reestablish this taxon as a distinct species.
Please refer to the following for species status update:
"Status is revised [2010] for the following taxa, which were previously treated as junior subjective synonyms or as subspecies and are herein raised to species status: ... Hyalophora gloveri (Strecker, 1872)... "


Other names include:
Hyalophora gloveri (Strecker, 1872)
Platysamia gloveri Strecker, 1872
Platysamia gloveri var. reducta Neumoegen, 1891
Platysamia columbia nokomis Brodie, 1894
Platysamia columbia winonah Brodie, 1894
Samia columbia Smith, 1865
Identification
Similar in appearance to Hyalophora columbia and often recognized as a subspecies.
NOTE: Still considered distinct by many and recent studies support the separation of columbia and gloveri.

Please refer to the following:

Please refer to the following for species status update:
"Status is revised [2010] for the following taxa, which were previously treated as junior subjective synonyms or as subspecies and are herein raised to species status: ... Hyalophora gloveri (Strecker, 1872)... "

The relationship of gloveri to columbia remains in debate. The recent synonymy of the gloveri-columbia group & their relationship(s) appear sound, but may be incomplete. The issues of morphology (adults & larvae), host affinities and relationships, reproductive compatability, blending (extent of blend zones), degrees of genetic variance, and divergence patterns (time frames) are all continued topics & issues of discussion. There may be some evidence in the afore-mentioned to substantiate distinct taxonomic status for gloveri (??)

The taxon, Hyalophora columbia ssp. gloveri, may be composed of several divergent populations representing distinct taxa and/or sub-taxa within the currently recognized "columbia species group", additional studies are needed to clarify observed differences.
Range
Glover's Silk Moth can be found along the easten and western slopes of the Rockies and Great Plains, south into Mexico and north to Canada. Spurious populations can be found in the western Plains and foothills of the Rockies (esp. SD & ND in the USA and Prairies of c. Canada). Populations can also be found where conditions are favorable across the Great Basin extending west to the eastern slopes of the Sierra Nevadas and Cascades.

MEXICO:
n. & c. Mexico ("Mexican Variants")
The range is not well defined but seems to include at least a few of the northern and central Mexican States.
Incl. Sonora, Chihuahua, Durango, & Coahuila, + additional spurious reports from central Mexico(?)

CANADA:
"c. Canada" (complete range is in debate)
Incl. e. British Columbia, s. Northwest Territories (?), Alberta, Sakatchewan, Manitoba & extreme w. Ontario
(Not sure of details)
Typical forms occupy much of the Canadian range.

An unusual phenotype known as "nokomis" (previously a separate ssp.) occurs in the Plains/Prairies of c. Canada. Form "nokomis" is no longer recognized as distinct and may represent a natural blend zone with H. cecropia (??).

In zones of contact with H. columbia nominate to the east, there appears to be some intergradation but this mixing is more limited in range than seen with euryalus to the west (placing the columbia-gloveri conspecific relationship in question by some.).

USA: Texas, New Mexico, Arizona, w. Oklahoma, Colorado, Wyoming, w. South Dakota, w. North Dakota(?), Montana, Idaho, Utah, Nevada, eastern California, and e. Oregon
(NOTE: Populations in s. NM & s. AZ are often akin to the "Mexican variants")

In n. Idaho, w. Montana, e. Oregon (?) and e. Washington, gloveri is replaced by several anomalous hybrid populations with indistinct taxonomic status (incl. "kasloensis").

Populations of the H. gloveri-columbia group ("ssp. gloveri") from c. Mexico north into se. Arizona/sw. New Mexico appear to be slightly divergent from most other gloveri (Clinal?).

NOTE: Specimens from central Mexico are often more striking and divergent in appearance.
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The range of Hyalophora columbia gloveri (syn. Hyalophora gloveri) overlaps with the following taxa and several hybrid populations have been identified.

Limited introgression in the western Plains and eastern Rockies
Very limited mixing with columbia nominate

Gloveri overlaps and blends extensively with euryalus along the Cascades and Sierra Nevadas forming several hybrid groups.

For more information on blend zones within the Genus Hyalophora, refer to the following:
Habitat
Usually Alpine and Riparian (scattered in and among adjacent suitable habitats incl. foothills of the western prairies)
Season
Depending on location and weather patterns, life cycle activity (egg-adult) ranges from April/May-September.
Adults are usually observed to fly from May to June (late July-August in s. AZ & n. Mex with larvae being seen from July to September/October).

*Populations located across se. Arizona (Sonoran Region) have been observed to have 2 flight periods (generations). Although univoltine across most of the range, pop's in se. Arizona and n. Mexico have been observed to be partially bivoltine (altitude and annual precip seem to play a role). Adults in se. Arizona can be observed during a "first flight wave" in the spring and a "second flight period" in the late summer; the greatest numbers of adults are usu. observed to fly from late July to mid-August. The larvae of these later populations are often active through October.
Food
Several Trees and Shrubs in the Rosaceae esp.. Prunus spp., Willows, and Larch ... additional hosts are numerous incl. many other woody plants

larvae may eat leaves of alder, birch, Antelope Bitterbrush (Purshia tridentata), buckbrush (Ceanothus spp.), buffaloberry, cherry, rose, Russian Olive (Eleagnus angustifolius), willow

-----------------------------------------
The following list of host plants is based on gloveri populations in w. Montana and was contributed by P. White (pers. observ. & experiences).

wild caterpillars have been found on the following:
chokecherry
sandbar willow
australian "green" willow
native "yellow" willow
bitter brush(solitary food plant of gloveri in the Island Park ID region)

Larvae were reared or attempted in captivity on the following:
chokecherry*
northwest sandbar willow (Salix exigua)*
australian "green" willow+
coral bark willow or scarlett willow (Salix alba)+
bitter brush~ (larvea rejected plant after 3rd instar)
golden currant (Ribes aureum)-
wax currant (Ribes cereum)-
wild rose~ (larvae rejected plant after 2nd instar)
red alder (Alnus rubra)+
apple-
(found a 5th instar nibbling on a lilac bush below apple / may have fallen/wandered off the apple tree ??)

(*plants=most successful)
(+plants=high growth rate)
(no symbol=average growth)
(- =slow growth rate)
(~plants=impossible)
Life Cycle
Holometabolous

GENERALLY described as having one generation per year; eggs are laid singly on food plant, and hatch in 8-19 days, depending on temperature; overwinters as a pupa in spindle-shaped cocoon attached lengthwise to twig or trunk of tree or shrub and emerges as an adult the following spring or summer

Univoltine across most of the range, some populations have been observed to be "bivoltine" (or "partially bivoltine" = "split brooded") in se. Arizona, New Mexico and n. Mexico (altitude, weather patterns and annual precip seem to play a role). These populations are also divergent in some of their physical traits; however, it is not known for certain whether these observed differences are environmentally induced or genetic (some preliminary captive rearing suggests their is a strong genetic component which appears to be subject to environmental influences .... but more work is needed!).

1) eggs may be laid singly or in groups on or near the leaves of host plants

2) hatching occurs within 9-14 days

3) larvae feed for 6 to 8 weeks (July-August)

3) overwinters as a pupa in tough, compact, teardrop-shaped cocoon usu. attached longitudinally to twig or outer part of host plant, often spun at the base of the host or in weedy tickets nearby (much less obvious than that of cecropia and often difficult to find), the outer layer of the cocoon is rugose & heavily striated, often concealed by and incorporats leaves and twigs of the host plant

4) adult eclosion occurs the following spring/early summer (May-early July)

5) Mating usually occurs in the predawn hours as seen in most other Hyalophora species
Remarks
The taxon, Hyalophora columbia ssp. gloveri, may be composed of several divergent populations representing distinct taxa and/or sub-taxa within the currently recognized "columbia species group", additional studies are needed to clarify observed differences.

The relationship of gloveri to columbia remains in debate. The recent synonymy of the gloveri-columbia group & their relationship(s) appear sound, but may be incomplete. The issues of morphology (adults & larvae), host affinities and relationships, reproductive compatability, blending (extent of blend zones), degrees of genetic variance, and divergence patterns (time frames) are all continued topics & issues of discussion. There may be some evidence in the afore-mentioned to substantiate distinct taxonomic status for gloveri (??)

Please refer to the following for species status update:
"Status is revised [2010] for the following taxa, which were previously treated as junior subjective synonyms or as subspecies and are herein raised to species status: ... Hyalophora gloveri (Strecker, 1872)... "



Hyalophora columbia ssp. gloveri
USA & Canada / Rocky Mountains, Western Plains, and Great Basin e. of the Sierras

NO IMAGE AVAILABLE
Plains of Central Canada
Synonymized with gloveri
Form "nokomis" is often described as being a diminutive & slightly divergent population from the nominate gloveri. Many specimens identified as nokomis often appear to possess characteristics suggestive of cecropia influence, particularly red scaling along the postmedial bands ...... possible blend zone???. Additionally, the range and locality data for many specimens identified as "nokomis" originate from areas of likely contact between the potential parent taxa - "cecropia x gloveri"
NOTE: The specimen pictured in the link below is strikingly similar to many "cecropia x gloveri" hybrids and blends

NO IMAGE AVAILABLE
Hyalophora columbia ssp. gloveri ("var. reducta")
Rocky Mountains of the USA & Canada (High Elevations)
Synonymized with gloveri. Described as being a high altitude diminutive form. Specimens identified as reducta have been reported along the Rockies and are likely the result of environmentally induced traits. The small size and compact appearance does not seem to be genetic. Stocks collected at higher elevations and reared at lower ones seem to produce "normal sized and patterned adults".


Hyalophora columbia ssp. gloveri ("Mexican variants")
sw. USA - incl. se. Arizona & sw. New Mexico - south into central Mexico

Hyalophora pop's from the mountains of central Mexico north into the Sonoran region of n. Mexico & se. Arizona (sw. New Mexico) "appear to be" geographically & temporally restricted from most other Hyalophora. These populations deviate from other columbia/gloveri as follows:

1) Peak time of year for adult activity
(Often bivoltine with an active late July-August emergence and a smaller spring emergence between April-early June)

2) Slightly larger size
(often approaching that of cecropia)

3) Degree of coloration & pattern (refer to the images below for details)

"Sonoran Variants"


for comparison (Recto)
Great Basin - i.e. "Typical gloveri"


NOTE:
a) Extensive reddish-burgandy coloration extending "submarginally" as seen in euryalus - as opposed to the softer gray coloration typical of most other "gloveri" populations. There has been some thought, this increase in reddish coloration may be environmentally induced. There is a tendency in several of the Hyalophora species to exhibit more red when exposed to warmer temperatures (less dramatic temp differentials between day and night = "more reds").
b) They exhibit tremendous variability in the shape and size of the discal crescents, ranging from long euryalus-like to short columbia/gloveri-like to absent in some examples.
c) The presence of a discernable red postmedial band - best viewed ventrally (a trait typical of cecropia)

"Sonoran Variants"


for comparison (Verso)
Great Basin - i.e. "Typical gloveri"


NOTE: Specimens from central Mexico are often more striking and divergent in appearance. Recent studies place the relationships of the red forms (i.e. similar looking) sw. US (se. AZ & sw. NM) & n. Mex. (Sonora & Durango) populations and those occurring in c. Mexico as quite divergent with regards to genetic relationship; however, much of the area between these populations remains poorly surveyed/collected and additional collecting endeavors & studies of intermediate populations may shed more light on lingering questions and relationships.

These members of the "columbia species group" often spark debate among specialists and hobbyists alike. "Are they possibly ancient hybrids, a distinct subspecies or something else"???

HYPOTHETICAL: In discussion with several hobbyists and Saturniid specialists, it is thought these moths may represent the closest living members to the ancestral Hyalophora(?)

for details, refer to the following link: Hyalophora mexicana sp. n.
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H. columbia columbia:

ne. USA, Great Lakes region of US & Canada, & much of e. Canada