172
V. G. DETHIER
planation involves simple diffusion and dispersal of odorous material.
This idea is consistent with the facts of orientation as known.
V. MATING BEHAVIOR:
OROSOPHILA
Descriptive accounts of courtship and mating behavior among insects
are numerous and of long-standing occurrence. Analyses of the significance of this behavior are of more recent origin. Probably the most
important and rewarding attempts to ascertain the significance of this
behavior have been undertaken with flies of the genus
Orosophila.
Because of the hallowed position occupied by these flies in the field
of genetics, their behavior has been examined more critically perhaps
and with greater attention to its relation to speciation than that of any
other insects. While the role of the chemical senses in mating behavior
has been fully appreciated in the spectacular behavior of male moths
in assembling to females, the part played by chemical senses in other
aspects of sexual behavior in other insects has been rather generally
neglected in favor of the part played by vision and the mechanical senses.
Recently, however, information pertaining to the chemical senses has
increased in volume, with the result that the extremely important role
played by this sense modality can no longer be ignored. The most extensive studies have been directed toward an understanding of the
situation in Orosophila and in the cockroaches.
The courtship of Orosophila is a complex affair which varies in some
details from species to species; however, certain characteristics are general to the genus. The sequence of events which may occur are the
following: (1) tapping, a motion of the prothoracic legs of the male
against the legs or body of the female which initiates courtship,
(2) posturing, involving simple or complex patterns of wing, leg, and
proboscis movements, (3) rejection by the female, a performance which
may take the form of moving away (decamping), extruding (appression
of the vaginal plates, etc.), ignoring the male, or kicking, etc., (4) acceptance by the female (spreading apart of the vaginal plates), (5) licking by the male, (6) mounting, especially in the subgenus
Orosophila
(Spieth, 1952). Tapping and licking are the most invariable acts performed by the males of the genus; from the point of view of the present
discussion they are the most important. By means of tapping, the male
is able to recognize his own species, and the males of certain species can
recognize the sex of the fly being tapped. If the male taps a foreign female, the courtship ceases at this juncture; otherwise the courtship
proceeds. Many males can recognize a male of their own species and
stop courtship. Males of D. virilis and D. repleta, apparently unable to
distinguish between sexes of their own species, continue courting. In an
V. G. DETHIER
planation involves simple diffusion and dispersal of odorous material.
This idea is consistent with the facts of orientation as known.
V. MATING BEHAVIOR:
OROSOPHILA
Descriptive accounts of courtship and mating behavior among insects
are numerous and of long-standing occurrence. Analyses of the significance of this behavior are of more recent origin. Probably the most
important and rewarding attempts to ascertain the significance of this
behavior have been undertaken with flies of the genus
Orosophila.
Because of the hallowed position occupied by these flies in the field
of genetics, their behavior has been examined more critically perhaps
and with greater attention to its relation to speciation than that of any
other insects. While the role of the chemical senses in mating behavior
has been fully appreciated in the spectacular behavior of male moths
in assembling to females, the part played by chemical senses in other
aspects of sexual behavior in other insects has been rather generally
neglected in favor of the part played by vision and the mechanical senses.
Recently, however, information pertaining to the chemical senses has
increased in volume, with the result that the extremely important role
played by this sense modality can no longer be ignored. The most extensive studies have been directed toward an understanding of the
situation in Orosophila and in the cockroaches.
The courtship of Orosophila is a complex affair which varies in some
details from species to species; however, certain characteristics are general to the genus. The sequence of events which may occur are the
following: (1) tapping, a motion of the prothoracic legs of the male
against the legs or body of the female which initiates courtship,
(2) posturing, involving simple or complex patterns of wing, leg, and
proboscis movements, (3) rejection by the female, a performance which
may take the form of moving away (decamping), extruding (appression
of the vaginal plates, etc.), ignoring the male, or kicking, etc., (4) acceptance by the female (spreading apart of the vaginal plates), (5) licking by the male, (6) mounting, especially in the subgenus
Orosophila
(Spieth, 1952). Tapping and licking are the most invariable acts performed by the males of the genus; from the point of view of the present
discussion they are the most important. By means of tapping, the male
is able to recognize his own species, and the males of certain species can
recognize the sex of the fly being tapped. If the male taps a foreign female, the courtship ceases at this juncture; otherwise the courtship
proceeds. Many males can recognize a male of their own species and
stop courtship. Males of D. virilis and D. repleta, apparently unable to
distinguish between sexes of their own species, continue courting. In an