Utah Butterfly and Skipper Species' Descriptions

Pieris sisymbri Northern Utah segregate 

(Spring White)

Adults	Mature Larva (On Arabis spp.)
Example of habitat	Example of hostplant--Isatis tinctoria

General:

        The Type Locality of P. sisymbri sisymbri is north of San Francisco, California;  Boisduval.  According to the designations of Howe in "Butterflies of North America," plate 70, figs 21-22, specimens from the Wasatch Front belong to this race. 

Utah Distribution and Habitat:

        Pieris sisymbri sisymbri flies along the Wasatch Range from Box Elder County in the north to Utah County in the south.  Colonies of P. sisymbri sisymbri in Juab County are replaced by P. sisymbri nigravenosa.  (Further research would be helpful in understanding the exact ranges of P. sisymbri sisymbri and P. sisymbri nigravenosa to see if the two taxa overlap and their propensity to produce clinal populations.)

        At the same time, clines of Pieris sisymbri sisymbri and Pieris sisymbri flavitincta can be encountered in Cache County at the vicinity of Blacksmith Fork Canyon.  As you continue northward, phenotypes of pure P. sisymbri flavitincta begin to completely replace the nominate race.

       Males of P. sisymbri favor hilltopping making collecting in canyon bottoms less productive.

Bionomics:

       Hostplants for Pieris sisymbri sisymbri include Isatis tinctoria, Arabis perennans, Arabis sparsiflora var. subvillosa, Descurainia pinnata, and Cardaria draba.    Lab rearing of P. sisymbri sisymbri is fairly easy since mustards such as White top (Cardaria draba,) and Dyar's Woad (Isatis tinctoria,) grow in Utah's urban and suburban communities.  

       Note:  Those who wish to rear P. sisymbri in the lab should avoid using Descurainia sophia.  Although females of P. sisymbri will oviposit on montane-growing D. sophia that grows with D. pinnata, larvae, ultimately, will perish on D. sophia because of poisonous toxins.  Descurainia sophia can be a trap for new lepidopterists wanting to raise montane pierids like Anthocaris spp., Euchloe spp, and Pieris (Pontia) spp,  because of its availability in nearby disturbed city neighborhoods.  Nevertheless, larvae of P. sisymbri and A. stella browningi will accept this mustard in the lab; but will later die.  (In the case of A. stella, they will die rather quickly.)

       Females of P. sisymbri use Arabis spp. both as a larval food plant as well as a nectar source.  Many times females of P. sisymbri will nectar on the flowers and then fly down to the basal leaves to deposit an ova; only to return again to nectar.  Females will often repeat this course of action--laying as many as eight ova on a single Arabis plant.  (Their oviposition preference almost always seems to be down below on the basal leaves--contrasted to Anthocaris stella browningi and Euchloe ausonides coloradensis females which lay their eggs as singletons on the flowers.)

       The ova are green turning orange after 24 hours; hatching in about 4-5 days.  First instar larvae are cannibalistic and will consume other sisymbri ova that it finds as it works its way up the main stalk of the hostplant towards the flowers.  

       The young first instar larva is light colored with a dark head.  Second and third instar larvae of P. sisymbri oftentimes will surprise lepidopterists in the field as they can be stunningly blackish in appearance.  As the larva moults into later instars, an appearance similar to the mature larva of a black and yellow striped caterpillar begins to appear.  

       Hibernation is as pupa.  For those rearing P. sisymbri in the lab, some pupae will bypass emergence after 1 year and will emerge during the second or third year of diapause.  

Todd Stout

All images of Limenitis weidemeyeri on the ULS Info Bar courtesy Jay Cossey                                                                    

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