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Insect bauplanInsect bauplan
headhead abdomenabdomenthoraxthorax
Adult insects have 3 major body regions, six legs (on pair on each segment of the thorax), one pair of antennae and usually two pair of wings as adults (attached to last two segments of thorax).
Some characteristics of insects
• Invertebrate – exoskeleton
• Segmented body
• Dorsal heart
• Largely terrestrial
• Metamorphosis
The insect nervous system
• brain
• ventral nerve chord organised into ganglia (local nervous centres – one per segment)
Insect breathing
• Insects have no lungs!
• Have a network of air tunnels (tracheae)
• Openings to outside are called spiracles
Insect orders
Coleoptera
Lepidoptera (Butterflies &moths)
Diptera (Flies, mosquitos andgnats)
Hymenoptera (wasps, ants,bees, sawflies)
28 Small orders: Dragonflies,grasshoppers, termites, lice,true bugs, cicadas, fleas etc.
Social insects
• Most are hymenoptera, e.g. ants, wasps and bees (but there are also 10s of thousands of solitary species among the bees and wasps)
Consider this:
• Social insects, had “invented” division of labour, agriculture, castes, slavery, territorial wars, consensus building, “cities” with fantastic architecture and a symbolic “language” - 10s of millions of years before there were humans.
Slave making ants• Ants of the Polyergus samurai species pulling out larvae
and pupae of the Formica japonica species from the entrance of the nest they have raided.
Different morphologies for different specialists
• Worker ant (left) of the species Pheidole nodus species feeding a soldier of the same species (right)
Consensus building
• Finding a suitable nest site: bee swarms
From: Leadbeater & Chittka 2007 Current Biology
oriented danceoriented dance disoriented dancedisoriented danceFrom Dornhaus & Chittka 2004 Behav Ecol Sociobiol
Measuring foraging success
12,035 kg
Daily weight changes of a beehive can be measured on a scale - this reflects mostly nectar intake
0
20
40
60
80<
-0,3
00
-0,3
00
-0,2
00
-0,1
00
0,0
00
0,1
00
>0
,20
0
Weight change of beehive in kg
% o
f d
ays
with disoriented dances
with oriented dances
Temperate habitat (Central European)
0
20
40
60
80
<-0
,30
0
-0,3
00
-0,2
00
-0,1
00
0,0
00
0,1
00
>0
,20
0
Weight change of beehive in kg
% o
f d
ays
with disoriented dances
with oriented dances
Temperate habitat (Mediterranean)
0
20
40
60
80<
-0,3
00
-0,3
00
-0,2
00
-0,1
00
0,0
00
0,1
00
>0
,20
0
Weight change of beehive in kg
% o
f d
ays
with disoriented dances
with oriented dances
Tropical habitat (India) - days of high nectar intake are missing without
location communication