34 G. W. KIRKALDY ON THE STRIDULATING ORGANS 



evening seems to be the favourite time, and from May till the 

 middle of June. The apparent movement of the fore-legs across 

 the striated " upper lip " is indicated as a probable source of the 

 sound. It is unnecessary to do more than refer to similar notes 

 by Eedfern (5) and Bach (6). In 1874 Landois (7) described the 

 " comb " on the anterior tarsus of the male in Corixa and its 

 action (as he thought) on the last segment of the rostrum. 

 In 1877 Swinton discussed (8) stridulation in waterbugs, being 

 apparently ignorant of the previous literature except the notices 

 of Frisch (1) and Ball (2). Swinton called attention to, and 

 figured some minute limae on the mesonotum, which he con- 

 sidered acted with the overlapping pronotum to produce sounds. 

 These limae were noted in Ihjocoris chnicoides, Nepa cinerea and 

 Corixa spp., while in Xotonecta glauca two obliquely striated bands 

 were figured. These limae and bands, however, do not actually 

 ai)pear to exist, and the under surface of the pronotum does not 

 seem to be sufficiently mutually modified. Later (1878 or the 

 early "eighties"?) the same author (9) rediscussed the question. 

 He does not appear to have investigated the subject very 

 thoroughly, since he states, as a rule, that " in the Heteroptera 

 both sexes stridulate," while a more careful examination of 

 Corixa (one of the genera he discussed) would have convinced him 

 of his error. 



Schmidt-Schwedt (10) confirms Landois' statements, without 

 being aware of their existence; while Bruyant (11), apparently 

 ignorant of previous literature, except Schmidt-Schwedt's veiy 

 brief note, records Micronecta {Sigara Bruyant) as a musical 

 insect. Bruyant refers the production of the tone to the rapid 

 movement of the bristly hairs of the anterior tarsus on the 

 rostrum, and compares the monotonous, not at all metallic, 

 stridulation to the sound produced by the teeth of a comb 

 playing upon the edge of a thin plate. This stridulation is 

 characteristic, and enabled Bruyant to rediscover the tiny bug 

 at several places in the Auvergne. Almost contemporaneously 

 Mrs. Thompson recorded (12) two distinct sounds in Corixa 

 (male), and in the same year Carpenter (13) discussed the 

 question, coming to the same conclusions that Landois had twenty 

 years before. "Various short notes followed in the Irish Naturalist 

 for the ensuing year, and the subject was alluded to by Carpenter 

 again (14 and 16), Miall (15), Sharp (17), etc., though no further 



