190 
HYMENOPTERA. 
to the winged male. Our luminous beetles are so in both sexes and in 
the larvae, so that this luminescence may not be connected with sex. A 
better example are the singing insects, in which the males sing, the 
females are silent. We have briefly discussed this elsewhere (under 
Cicadidce) and it is not certain that song is really connected with sex, 
though it is likely to be so. In a great number of male moths and butter¬ 
flies, scent production from special hair tufts is a feature of the males 
alone and the frequency with which this occurs points to its being an 
important factor in successful mating. The variety of situations in 
which these tufts occurs, their diverse form and size are marked features, 
for instance, in our Noctuid^e and Pyralidse, while the male pouch and 
sexmarks of butterflies are simply scent producing organs. 
Haase discusses this point (Zool, Anzeiger, XI, 1888, No. 287). 
Plateau remarks that in Lepidoptera, scent organs exist for three pur¬ 
poses ; in Danais and Euploea, they are defensive, the scent being unplea¬ 
sant and derived from a caustic fluid ; in some Lepidoptera, notably 
Bombycidge and Saturniidee, the scent is diffused by the female to 
attract the male, the latter having very sensitive organs of smell ; in 
many butterflies the males emit a “ seductive ” scent, that has in some 
cases been compared to vanilla, and which is employed only in court¬ 
ship. It is the last which Haase discusses ; he states that scent organs 
occur in one of the following positions : 
Wings. —On the whole upper surface of both wings. (Pieridce). 
In tufts on the upper surface of both wings (some Satyr ides). In a 
costal fold of the forewing (some Hesperiidce). On the upper surface 
of the disc of the forewing ( Cynthia, Atella, Argynnis, etc., and some 
Hesperiidce). On the lower surface of the disc of the fore wing (Eu- 
rema , etc.). On the folded costal edge of the hindwing ( Patula). 
On the upper surface of the hindwing (Pierids, Danais, Morphides, 
Satyr ides, etc.). 
On the anal area of the hindwing above (Papilionides , Ornithop- 
tera , Pompeus, etc.), or below ( Morphides ). 
On the lower surface of the hindwing (Plecoptera in Noctuidae). 
On the part of the two wings which rub together when in motion (Catop- 
silia, Euplcea , Ergolis , Morphides, Mycalesis, Lyccenides, some Hespe- 
riides and some Heterocera). 
Thorax and abdomen. —Many Sphingids, Agaristids and some Noc- 
tuids have scent organs on the first abdominal segment. In some 
Pierids, in all Danaids, in Callidulids and some Noctuids, a tuft of odo¬ 
rous scales can be protruded from each side of the genital aperture. 
Palpi and Legs. —In a Deltoid (Bertula) a tuft occurs on the palpi, 
in a few forms tufts occur on the tibiae of all the legs, on the forelegs 
only (Spodoptera), on the middle tibiae (many Noctuidce ), on the hind 
tibia? (some Hesperiidce, Hepialidce, Hyblcea and many Geometridce). 
