Panorpa sigmoides Carpenter, 1931
Diagnosis: This species belongs to the nebulosa group with speckled wings and males without an anal horn on the 6th abdominal tergite. It also belongs to the subgroup in which males have a cluster of spines at the meso-apical corner of the basistyles, and a series of bristles along the mesal surface of the ventral parameres. It can be separated from all other species, except P. capillata, by the male ventral parameres being sigmoidally shaped with a cluster of thick, small bristles subapically. Males of P. sigmoides can be separated from P. capillata by the glabrous ventral surface of the ventral parameres and the dark spines along the mesal surface of the hypovalves.
Distribution – Geographical: This species is found in the upper Midwest U.S.A. from Ohio westward to the unglaciated area of northeastern Iowa and eastern Minnesota.
Distribution – Temporal: 2 May to 3 August with most adults emerging in June.
Ecology: This species can be locally abundant in the deciduous forests, resting on understory herbaceous vegetation in deeply shaded areas. In Iowa, presence of P. sigmoides appears to be strongly correlated with forests of the unglaciated area of the northeastern part of the state.
Biology: Nothing is known of the immature stages or life history of this species.
Notes: The morphological characters that separate P. sigmoides from P. capillata are not great, but geographical distributions do not overlap. It could easily be argued that these are two subspecies of the same species.
The name sigmoides refers to the sigmoidally-shaped male ventral parameres of this species.
Carpenter, F.M. 1931. Revision of the Nearctic Mecoptera. Bulletin of the Museum of Comparative Zoology. 72:205-277.