Tetracis fuscata (Hulst)

Ferris, Clifford D. & Schmidt, Christian, 2010, Revision of the North American Genera Tetracis Guenée and Synonymization of Synaxis Hulst with Descriptions of Three New Species (Lepidoptera: Geometridae: Ennominae), Zootaxa 2347, pp. 1-36 : 16

Tetracis fuscata (Hulst)

( Figs. 27–29 , 91 , 106 , 122 , 137 )

Synaxis fuscata Hulst, 1898 . Descriptions of new genera and species of the Geometrina of North America. Canadian Entomologist 30(8): 217. Holotype ♂, Glenwood Springs [Garfield Co.], Colorado [AMNH]. Note: Hulst, 1898, misspelled the locality as “Glenmore Springs.”

Diagnosis: The angulate black DFW PM line, well-defined brown-black AM line, and lack of bipectinate antennae in males separate fuscata from its congeners formosa and gray forms of hirsutaria .

Description: Adults ( Figs. 27–29 ): FWL: 19–23 mm. Antenna light brown and serrate in male; in female nearly filiform, densely setose ventrally. Palpi slender, porrect, about 1.5x eye width, banded brown and fuscous. Head, thorax, abdomen, legs grayish-brown (Hulst’s “dirty fuscous”); abdomen speckled with dark scales. Wings: Grayish brown, well-peppered with dark scales. DFW with brown-black AM and PM lines; PM line angled basad at M3; MB only slightly darker than rest of wing; small discal spot present. DHW with poorly developed and incomplete dark median line; discal spot absent. Ventrally paler with dorsal markings lightly repeated. Female slightly larger and paler than male. Male genitalia ( Figs. 91 , 106 ): Uncus broad, slightly decurved, tapering to bluntly pointed tip. Dorso-caudal margin of gnathos concave with a robust upcurved spine at either side. Stubby robust furca from middle of anellus tapers to rounded apex, slightly enlarged before apex. Valve moderately broad with even margins, tapering to narrow rounded apex with a small triangular apical projection at the dorsal margin. Aedeagus with ring of spinules at posterior end at base of vesica; everted vesica with patch of sclerotized nodules on dome. Female genitalia ( Fig. 122 ): A/P = 0.44. Long unsclerotized tubular ductus bursae (ca. 2x length of corpus bursae). Corpus bursae ovoid with small oval dentate signum located about 2/3 length of bursae above fundus.

Material examined: 33 specimens with 3 dissections.

Biology: Unknown. The timing of the adult flight in late August into September varies annually depending upon climatic conditions and flight ceases with the onset of the first hard mountain frost.

Distribution ( Fig. 137 ): UNITED STATES: COLORADO. Garfield, Larimer. WYOMING. Albany (Snowy Range Mts., Sherman Hills at southern end of Laramie Range) 7600–8200’ (2320–2500m).

Figures

FIGURES 27 – 41. Tetracis adults: 27 – 29. T. fuscata, 27 – 28. Albany Co., WY, 29. Mesa Co., CO; 30 – 34. T. pallulata, 30. British Columbia, 31, 34. Curry Co., OR, 32. Plumas Co., CA, 33. Clark Co., NV; 35 – 38. T. mosesiani, 35 – 36, 38. Monterey Co., CA, 37. Los Angeles Co., CA; 39 – 41. T. j. jubararia, 39. Coos Co., OR, 40 – 41. Alameda Co., CA.

FIGURES 87 – 94. Tetracis male genitalia with aedeagus removed and aedeagus with vesica everted. 87. T. crocallata. 88. T. cachexiata. 89. T. cervinaria. 90. T. australis. 91. T. fuscata. 92. T. pallulata. 93. T. mosesiani. 94. T. j. jubararia. Aedeagus enlarged relative to remaining structures.

FIGURES 102 – 117. Tetracis male genitalia, domes of everted vesica. 102. T. crocallata. 103. T. cachexiata. 104. T. cervinaria. 105. T. australis. 106. T. fuscata. 107. T. pallulata. 108. T. mosesiani. 109. T. j. jubararia. 110. T. j. sericeata. 111. T. montanaria. 112. T. barnesii. 113. T. formosa. 114 – 115. T. hirsutaria. 116 – 117. T. pallidata.

FIGURES 118 – 124. Female genitalia with enlarged view of signa. 118. T. crocallata. 119. T. cachexiata. 120. T. cervinaria. 121. T. australis. 122. T. fuscata. 123. T. pallulata. 124. T. mosesiani.

FIGURES 137 – 139. Tetracis distribution maps. 137. T. fuscata. 138. T. pallulata. 139. T. montanaria.