3rd Instar
Egg
|
1st Instar
|
2nd Instar
|
3rd Instar
|
4th Instar
|
5th Instar
Specifications
Body and Head (x6)
|
Body Length:
|
10 to 14 mm
|
|
Body Width:
|
2 to 3.5 mm
|
|
Front Tentacles:
|
1.7 mm
|
|
Back Tentacles:
|
0.9 mm
|
|
Head Capsule:
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1.5 mm in diameter
|
Appearance
The black and yellow bands on the abdomen of a third instar larva are darker and
more distinct than those of the second instar, but the bands on the thorax are still
indistinct. The triangular patches behind the head are gone, and have become thin
lines that extend below the spiracle. The yellow triangle on the head is larger,
and the yellow stripes are more visable. The first set of thoracic legs are smaller
than the other two, and is closer to the head.
Third instar larvae usually feed using a distinct cutting motion on leaf edges.
Unlike first and second instar larvae, third (and later) instars respond to disturbance
by dropping off the leaf and curling into a tight ball. Monarch biologist Fred Urquhart
called this behavior "playing possum."
Color Pictures
