258 BEUTENMULLER, MONOGRAPH OF THE SESIIDJS. 



Cat. Ins. N. J. 1890, p. 288 ; Steinert, Deutsch. Ent. Zeit. (Berlin), Vol. V, 1892, p. 399 ; 



Haase, Ent. Zeit. Stett. Vol. L1V, 1893, p. 29-30 ; Caradja, Deutsh. Ent. Zeit. (Berlin), 



Vol. VI, 1893, p. 189 ; Tutt, Brit. Moths, 1896, p. 345, pi. xii, fig. 4 ; Beutenmuller, 



Bull. Am. Mus. Nat. Hist. Vol. VIII, 1896, p. 118 ; ibid. Vol. IX, 1897, p. 218 ; ibid. Vol. 



XII, 1899, p. 158. 

 Trochilia apiformis Heinemann, Schraett. Deutsh. und Schweiz, Pt. I, 1859, p. 12.0 ; Kranz, 



Schmett. um Miinchen, i860, p. 23 ; Wilde, Syst. Besch. der Raupen, 1861, p. 89. 

 Bembecia apiformis Nowicki, Enum. Lepid. Halicias Orient, i860, p. 23. 

 Sphinx vespiformis Hufnagel, Berlin Mag. Vol. II, 1766, p. 114. 

 Sphinx crabroniformis Denis and Schiffmuller, Verz. Schmett. Wien, 1775, p. 305 ; Engra- 



melle, Papilio, Europ. Vol. Ill, 1782, p. 32, pi. xci, fig. 121 ; Schneider, Neu. Mag. 



Liebh. Entomol. Pt. IV, 1792, p. 429 ; Hubner, Sam. Europ. Schmett. Schwarmer, 1796, 



p. 23, pi. i, fig. 51. 

 Sesia crabroniformis Olivier, Encycl. Method. 1825, pi. lxvii, fig. 4 ; Dumeril, Diet. Sci. Nat. 



Vol. XLIX, 1827. 



Male. — Head and palpi lemon yellow. Antennas black above, ferruginous below. Thorax 

 brown, with a large lemon yellow spot on each side in front, and a similar one on each side of the 

 posterior part. Sometimes the spots are united by a yellow dash along the patagia. Abdomen 

 with a very broad yellow band on the anterior part of each segment, except the last two, which are 

 entirely yellow ; posterior parts of segments narrowly brown. Legs yellow, slightly washed with 

 brown. Fore wings transparent, with narrow light brown borders and discal mark. Hind wings 

 transparent, with outer margin very narrow, brown. Discal mark absent. 



Female. — Much more robust than the male, with the second and fourth abdominal segments 

 usually wholly brown. Otherwise similar to the male. 



Expanse : Male, 30-35 mm. ; female, 40-45 mm. 



Habitat. — Europe, Siberia, United States westward to Nevada. 



Larva.—" Head round, dark red brown, epistoma whitish, sutures of clypeus and area about 

 mouth black ; labium, except palpal rings and sutures, white ; ocelli reduced, the lower posterior one 

 a pale spot without lens. Clypeus rounded a little above ; paraclypeal pieces strongly shield- 

 shaped ; a slight dent at apex of clypeus and one at each side at base. Body robust, somewhat 

 fleshy, incisures distinct, the annulations not strongly marked, the first annulet (tubercle i) the 

 highest by a very little. Shields faintly brownish, the brown curved lines indicated. Tubercles 

 small, normal ; setae distinct, brown. Anal flap with a tubercle on each side of the middle. Spir- 

 acles pale brown, brown rimmed. Crochets 8 to 13 in a row, rather degenerate, though of good 

 size, smaller posteriorly, those of joint 10 being especially weak and less in number. Outer part of 

 the ellipse more reduced than the inner one. Epicranial lobes of head somewhat broadly touch- 

 ing." — (Dyar, MS.) 



In popular parlance this species is known in England as the Hornet Moth, 

 owing to its striking resemblance to the large yellow hornet (Vespa crabro). In 

 Germany it is known as the Horniss-Schwarmer, Bienen-Schwarmer, Pappel- 

 Schwarmer, or Wespenvogel. It is very sluggish in habit and may be readily 

 captured. In Europe it is rather common, but in this country is rarely met with. 

 In the larval stage the species lives in the lower parts of the trunks and main 

 roots of poplar and willow and takes two years to come to maturity. The moth 

 emerges during June and July. 



