The New Mexico Rare Arthropod Resource

The Pinjuna Spalding’s Blue occupies grasslands and dry meadows near Pinyon-juniper woodlands (Scott 1986, Opler and Wright 1999, Glassberg 2001, Cary and Toliver 2024). They require sun exposure and can be found on hills and rocky outcrops (Glassberg 2001). As larvae their only known hostplant is Racemose Buckwheat also known as Redroot Buckwheat (Eriogonum racemosum) (Scott 1986, Opler and Wright 1999, Glassberg 2001, Cary and Toliver 2024) It requires Racemose Buckwheat in all parts of its range including easternmost part of its range at Eagle Nest Lake State Park (Cary and Toliver 2024). The butterfly is univoltine and eggs hatch immediately so larvae can feed and pupate before winter (Cary and Toliver 2024). 

The butterfly has one flight lasting from June to August  (Scott 1986, Opler and Wright 1999, Cary and Toliver 2024). New Mexico records stretch from June 27 to August 25 (Cary and Toliver 2024). Adults feed on flower nectar, Colorado populations favor James’ Buckwheat (Eriogonum jamesi) (Scott 1986). They are known to siphon nutrients in mud after summer rains (Scott 1986, Cary and Toliver 2024). When seeking females, males patrol all day near the hostplant, flying erratically .5 meters above the ground (Scott 1986).

Relying on grasslands, the butterfly will face the same threats as grasslands such as grazing. Though some argue grazing has no impact on different species and may even be beneficial due to decreased fire potential (fuel loads), there is some evidence over grazing may be harmful. For some butterflies, including the Sacramento Mountains Checkerspot Butterfly, grazing also directly degrades the habitat by reducing the health and abundance of host plants (by as much as 60% in some studies) (McIntyre 2010), and promotes the spread of invasive species, which outcompete host plants and change the composition of vegetation communities (Souther et al. 2019). Grazing not only limits host plant availability and degrades habitat but causes direct mortality of caterpillars and eggs as well. For example, mortality of post-diapause larvae may be higher due to trampling; this has been observed in the Sacramento Mountains (Pittenger and Yori 2003). 

Another threat facing this butterfly is catastrophic fire or lack of fire. The impacts of fire on this species may depend on the intensity and size of the fire, as well as seasonal timing (USFWS 2004). With population numbers in small areas one fire, controlled or wild, could wipe out a large percentage of what's left of this species and potentially cause its extinction (Cary et al. 2004, Wasserman et al. 2023). However, at the same time with no fire these grasslands may grow senescent or be succeeded which will also drive the taxa towards potential extinction (Cary et al. 2004,  Wasserman et al. 2023). The impacts of land use on fire intensity and spread may also be consequential. For example, grazing may temper a fire, as grazed meadows carry less fuel load, but the presence of some invasive grasses which are more abundant in grazed areas, such as Cheatgrass (Bromus tectorum), may cause more frequent fires due to invasive grasses adding novel and continuous fuels (USFWS 2004, Fusco et al. 2019). 

Invasive plants are also a threat to this butterfly as non-native species become more prevalent in grasslands (Gaskin et al. 2020). This butterfly is known to only use one hostplant (Scott 1986, Opler and Wright 1999, Glassberg 2001, Cary and Toliver 2024), the current conservation status of Racemose Buckwheat is unknown however, other species of Buckwheats are highly threatened by drought, invasive species, fire, development, and off road vehicles (USFWS 2009). Using just one species as a host plant (Scott 1986, Opler and Wright 1999, Glassberg 2001, Cary and Toliver 2024) leaves this butterfly at risk of environmental stochastic events that could affect the host plant such as extreme weather, wildfires, and predation (Forister et al. 2023). However, currently more research is needed on the threats to this host plant and butterfly.