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This page contains pictures and information for Sawflies, Bees, Wasps and
Ants that we found in the Brisbane area, Queensland, Australia.
 - A cluster of bees rested on grass stem during the late afternoon.
The insect order Hymenoptera includes sawflies, wasps, bees and ants. The
name Hymenoptera means 'membrane wings'. Their adults have two pair of membranous wings with the forewings lager
than the hind wings. The main defining characteristic of Hymenoptera is
that the front and hind wings are held together by a series of little hooks
called hamuli.
The female insects have strings to inject venom to their enemy where the
string is their modified ovipositor. Most insects in this order have a waist
that separates the thorax and abdomen. On their head they have two large
compound eyes and mandibulate mouthparts. Their antenna is medium in length and
usually strongly elbowed.
Most
larvae in this order are maggot-like and with no legs. However, the Sawflies
larvae look like caterpillars and sometimes mistaken as butterflies or moths
larvae. The insects in this order developed in complete metamorphosis.
Classification :
There are two suborders of Hymenoptera, the Symphyta (sawflies) and the
Apocryta (wasps, bees and ants)..
Suborder Symphyta - Sawflies
 Sawflies- Their adults look similar to wasps except they do not have the 'waist'.
Sawflies do not sting. They do not form the social organization like bees and
ants, but their larvae stay together for the defence. The female have their
special egg-laying tool, like a saw, to cut through leaf tissue for their eggs.
Sawflies are feed on nectar. Sawfly larvae are often caterpillar-like
with five or more abdominal prolegs
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Suborder Apocrita- Wasps, Bees and Ants
The suborder Apocryta are far more diverse than Symphyta and include all the
wasps, bees and ants. All of them have one common characteristic - their waist
in the middle of their body. Larvae are
maggot-like and with no legs.
Some of the members in this suborder are social insects, including some
wasps, bees and ants. They live in a highly organized group and each members are
divided into castes. Different castes perform different functions in the group.
It is believed that their special genetic configuration (haploid-diploid
sex determination) leads to their social behaviour. The social behaviour evolved independently three times (wasps, bees and ants) or even more in this insect order.
Besides
the social behaviour, there are other behaviors that only found in this
order, include the precise navigation skill and the communication capacity. All
the bees, wasps and ants can return to their nest after traveling kilo-meters
away. When they find the food source, they can tell the others where to
go.
Bees and Wasps sometimes look similar. The main difference between bees and
wasps is that Bees feed their larvae on honey, which is a mixture of pollen and
nectar, whereas wasps feed their larvae on meat, mostly paralysed arthropods.
 Parasite Wasps
- Parasitic Wasps are the largest group in Hymenoptera. Because of their
parasitic habit, most of them are still unknown. Their larvae are either
parasitic or predators. The female wasp usually locates the food plants of the
host then searches with her antennae for a suitable host.
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 Predatory Wasps- Wasps feed on nectar and they visit flowers. They are active day time.
Besides visiting flowers, they spend most of their time searching for host to
parasite or prey for their larvae. The ovipositors in most wasps are
modified into stingers. They will sting if disturbed.
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 Bees- Most bees live as individual, although the famous Honey Bees are social
insects. The solitary bees live in burrow under ground or in tree stems. In
their nests, there are chambers for their larvae, beside there are the storage
for the nectar and pollen.
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 Ants- Ants live in colonies made up of several castes. They included the winged
male, winged female and wingless workers. They all have waist. It is
composed of one or two knobs which are the first one or two segment of their
abdomen. Their antennae have a distinct elbow.
Questions for Discussion
Ants is considered the highest form in insects evolution. They evolved the
highly structured society. They have their powerful strings. They do not have
many predators. They seem dominate in the insect class. They are quite
different from others insects. However, if we learn more about Sawfly and wasp,
we can see the evolution track from Sawfly to Ants.
It is believe that the ancestor of hymenopterans, i.e., wasp, ants
etc., look like the Sawflies today. We can find the special features in
wasps and ants, the early
images are still retained in Sawflies.
- How they got their strings?
- Sawflies are closely related to wasps. They got their name because the
have their special egg-laying tool, like a saw, to cut through leaf tissue for
their eggs. Their adults look similar to wasps except they do not have the
'waist'. Although sawflies do not sting, they use their ovipositors to cut
open the surface of the leave to lay and insert their eggs inside. It is not
hard to imagine how they accidentally turn their ovipositors to their enemy
and become their weapon. By natural selection, their ovipositors become their
strings.
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- How they become the hard working parents?
- Although Sawflies do not supply food to their young, they guard them until
they hatch. The female sawfly will stay near the eggs and watch her baby come
out. Then usually she will die. But if some of the sawflies accidentally have
a habit that she brings some food to her baby, and those food are accepted by
her baby larva, it is a very good habit and natural selection will quit likely
select this. The larvae will have a much better chance to live and
become adults. Some of them will quite likely inherited the 'bring
food to larvae' character. This group of sawflies will become more in number.
The 'bring food to larvae' character will be enhance by evolution. After a
long time, this character diverged and become the different form of parental
care that we can see in wasp, ants and bees.
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- How they build their society?
  - There are quite a number of different theories that explain why some of
the hymenopterans are social insects. There is one or a few individuals who
lay eggs, most others are workers and help to look after the young.
It is general accepted that the major reason is the genetic structure
of hymenopterans so the the kinship of sisters are even higher than mother
and child. However I can see there is another factor, may be it is not as
important as the kinship theory, but could be important in the beginning of
the hymenopterans society evolution. We can see this from the sawfly. The
larvae of sawflies, unlike more other caterpillars of moths and butterflies,
are always stay together when at rest. If so happen that they stay together in
a nest even after some of them become pupa. Some of them become adults. Adults
lay more eggs in the nest. Adults bring foods to the nest. Now you can see the
primary form of the society has just formed.
[ Sawflies - Suborder Symphyta ] [ Predatory Wasps - Superfamily VESPOIDEA and SPHECOIDEA ] [ Bees - Superfamily APOIDEA ]
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