NO. 2 RECOGNITION AMONG INSECTS McINDOO 69 



each scent hair. Another quite common type in male moths is com- 

 posed of a pair of scalehke, scent hairs located at the base of the abdo- 

 men. Each tuft lies in a groove on either side of the body in the 

 pleura belonging to the first and second abdominal segments. A 

 large unicellular gland lies at the base of each scent hair. In the males 

 of Leucarctia and Pyrrharctia, a pair of invaginated sacs located at 

 the ventro-posterior end of the abdomen serves as a scent-producing 

 organ ; these sacs are lined with hairs. 



In the female moths Taumatopcea and Stilpnotia the scent-pro- 

 ducing organ consists of a paired tuft of scent hairs near the anus. 

 This organ in the female of Orgyia is a scent groove in the articular 

 membrane between the eight and ninth segments just above the anus. 

 Unicellular glands lie just beneath this thin membrane. The scent- 

 producing organ in the female of Bombyx nvori is the most highly 

 developed of any found in the female Lepidoptera. This organ is a 

 pair of invaginated and greatly folded sacs located at the posterior 

 end of the abdomen ; beneath the chitinous lining of these sacs lie 

 the unicellular glands. 



HYMENOPTERA 



Ants emit characteristic odors, but as yet little is known about 

 their scent-producing organs, nevertheless, a well-developed organ 

 has been found in the petiole, besides unicellular glands beneath the 

 articular membrane between the ninth and tenth abdominal terga, and 

 also some around the femoro-tibial and tibio-tarsal articulations. 

 A quite complicated, paired anal gland has been found in a few species 

 belonging to one subfamily of ants. Many wild bees and wasps emit 

 strong odors, but their scent-producing organs seemingly have never 

 been described. This organ in the honey-bee consists of a pouch 

 which is formed by the articular membrane between the fifth and 

 sixth abdominal terga. Unicellular glands lying just beneath the 

 membrane secrete a volatile substance which admirably serves as a 

 source for odors. 



BIBLIOGRAPHY 



Anthony, John. 1872. The markings on the battledore scales of some of 



the Lepidoptera. Month. Micr. Jour., v. 7, pp. 1-3, 250-252. 

 Arnhart, Ludwig. 1879. Ueber einen securidaren Sexualcharakter von 



Acherontia atropos. Verhandl. der k. k. Zool.-Bot. Gesellschaft Wien, 



Bd. 29, pp. 54-55. 

 AuBE, C. 1837. [Note on the fetid secretion of Eumolpns pretiosus.] Ann. 



Soc. Ent. France, t. 6, bul. p. Lvni. 



