|Anax parthenope (Selys, 1839), the
Lesser Emperor is a dragonfly of the family Aeshnidae. It is found in Southern
Europe, north Africa and Asia. In the east of its Asian range (including
China, Hong Kong, Taiwan, Japan, Korea, Southern Far East Russia, South
Siberia) the subspecies Anax parthenope julius (Brauer, 1865) occurs, which
might prove to be a distinct species.
Length around 71mm, the Lesser Emperor
is a larger insect, the blue band extends down the sides of the abdomen,
the eyes are green (as opposed to brown) and the abdomen is predominantly
greenish-brown (as opposed to yellow-brown in the Vagrant). Male Lesser
Emperors also have a waisted abdomen. Females are similar to males but
usually duller, lacking males pinched waist and having brownish, rather
than green eyes.
A. parthenope is smaller and less
colourful than its relative but much more common the Anax imperator (Emperor
Dragonfly). In general appearance, especially when seen on the wing, A.
parthenope is similar to A. imperator but A. parthenope tends to hold its
abdomen straighter than A. imperator. A large dragonfly seen in flight
with a bent abdomen is most likely to be A. imperator rather than A. parthenope.
A. parthenope has a very noticeable blue saddle at S2 and S3 which can
be seen in flight which is in contrast to the rest of the abdomen which
is brown. There is a yellow rin at the base of S2. The eyes are green.
It is similar to A. ephippiger although A. ephippiger is slightly smaller
and slenderer and its blue saddle does not wrap around S2 but is mostly
blue on top. A. ephippiger has brown eyes.
This rare vagrant is also likely
to be confused with Migrant or Southern Hawker. It is immediately told
from hawkers by the lack of black markings on the thorax. The most striking
feature is a pale blue band around abdominal segments 1 & 2, contrasting
with the rest of the largely plain brownish abdomen.
Breeds in ponds and small lakes and
can tolerate brackish water.
Like the Blue and Vagrant Emperors,
the Lesser Emperor has been extending its range Northwards. It's now a
fairly common sight as far North as the Netherlands, even though its European
home is still in the Mediterranean basin.
In the south of its range A. parthenope
can be on the wing in March. It is most commonly seen from June to September
but can still be around in November. Often seen patrolling around ponds,
lakes and other still water. Where it occurs with A. imperator it is usually
less abundant. When A. parthenope and A. imperator occur at the same ponds
A. imperator is dominant. Male and females mate in the normal dragonfly
manner and after mating the pair stay in tandem and egg-laying usually
occurs whilst still in tandem. This behaviour not seen in other European
hawkers with the exception of Aeshna affinis, although two migrants to
Europe, A. ephippiger and A. junius also oviposit in tandem. Eggs are inserted
into plants or in mud and hatch out in two months. Larval development takes