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Unformatted text preview: Mating Games: Finding a Mate,
Mating Behavior and
Reproduction Lecture Goals
The fascination with insect mating
How do insects reproduce?
Asexual and sexual reproduction
Implications of single and multiple
Sperm transfer and storage
Courtship and mating
Parental Care Green Porno Star Isabella Rossellini Takes on Insect Sex
A series of short films by Isabella
“I was always fascinated by the infinite,
strange and ‘scandalous’ ways
that insects copulate.”
sundancechannel.com/greenporno 1 Two Types of Asexual Reproduction
All insects are
female, live young
are produced. Aphids Two Types of Asexual Reproduction
= males (drones).
(drones) 2 Sexual Reproduction
Most insects reproduce sexually.
Mating involves sperm transfer from
males to females and involves several
Location of one sex by the
other (see insect communication)
Copulation and insemination Making More Insects: Reproductive
Anatomy Female Reproductive
Anatomy Storage organ for
sperm, honey bee queens
may store sperm for as long
as 25 years. 3 Male
V i d
some species. Making More Insects: Finding Mates How do insects attract
and recognize their
Chemistry, Vision, Sound
Courtship Rituals 4 How do insects attract and
recognize their mates?
Male leks Aggregation (lek) of male shieldbugs, Alien Empire
shieldbugs, Courtship Rituals
ritual? A courting pair of robberflies, Alien Empire Courtship Gifts This unnamed bush cricket
from Brazil is eating the
spermatophylax donated by
the male during mating.
--from Alien Empire After direct
of some insects
deposit material that
remains external t
This is highly
nutritious and is
usually consumed by
the female. 5 This female
scorpionfly is eating a
fly captured previously
by the male. The male
offers this as a nuptial
gift. The larger the
gift, the longer the
female will mate. If
she eats the gift
before mating is
complete she is quite
capable of terminating
sperm transfer is
--from Alien Empire Male danceflies
wrap a variety of
in silk and offer it as
a gift. Males often
snatch the gift away
from the female
when mating is
complete and use it
again in subsequent
mating. Males also
try to steal gifts
from other males.
--from Alien Empire Making More Insects: Pairing and
Copulation 6 Mating
Implications of single or multiple
Fitness, relationships between offspring How do males insure that their sperm
will be used to fertilize eggs?
•Some males may remove sperm deposited
in the female from other males
•May try to prevent additional mating
•May carry fertilized eggs for the female Pairing and copulation
Indirect insemination: Male produces a
capsule containing the sperm.
Capsule, droplet of sperm on a stalk, more
Males may place the sperm capsule on the ground
independent of female presence, or elaborate
methods to guide the female to the sperm
Females then insert the sperm into their
reproductive opening. Direct insemination: Among some insects,
the males may insert the spermatophore or it
can form during copulation. Spermatophore
Diversity 7 Sexual Reproduction
Direct Insemination: with or without a
Female still stores sperm in a special
internal container (spermatheca).
Males of many species either die after
mating or risk being eaten by the female
For example, the male dancing fly offers his
mate a diversionary tidbit to eat during
mating. Less lucky are male biting midgesmidgesthe female sucks out the contents of the
males body while he is in the process of
mating. Making More Insects: Reproduction
and Caring for Offspring Egg Laying Females have special structures for
laying eggs (ovipositor).
Eggs may be laid on the surfaces or
embedded in plants or other
substances. 8 Egg Laying The ovipositor is usually adapted for
piercing the substance in which the
eggs must be laid. It can be many
times the length of the insect. Egg Laying On the left, the very long ovipositor of a wasp that lays it’s
eggs in wood. Some bees and wasps use their stinger as an
ovipositor and invert it when not in use. On the right, the
eggs of a grasshopper, laid in a tunnel in the ground. Parental Care
Most insects lay their eggs
and then leave them to develop
without any parental care.
Protect their eggs.
Protect and feed their
offspring. 9 Parental Care Parental care is usually performed by females, the
male shieldbug is an exception, guarding the eggs of
its mate and protecting them from wasp parasitoids. Parental Care Female shieldbugs guard their offspring while they feed (left).
Female fungus beetles guard their offspring and guide them to
the fungi on which they feed (right). Parental Care
gives birth to live
young and remain
they can fend for
themselves. 10 Solitary Bees and Wasps A solitary bee seals her mud nest which she provisioned and
inserted a single egg (left). A solitary wasp uses a pellet of
earth to tamp her nest closed. She provisioned the nest with
paralyzed caterpillars. Sociality: the Most
Care Bees Ants Termites Questions about insect
– What is the importance of insect
fecundity to their success?
– How do insects with very short
lives enhance their ability to find
one another and mate?
– How does our culture and impact
on the environment interfere with
insect mating? 11 ...
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This note was uploaded on 10/03/2009 for the course ENT 1 taught by Professor Ullman during the Fall '08 term at UC Davis.
- Fall '08