Tuesday, July 29, 2014

Early Stages of Glassy Tiger

Glassy Tiger; Female butterfly resting on young shoot of its host plant
The female butterfly lay eggs singly on the immature leaves of larval host plant; Dregea volubilis [Linn.f.]. Freshly laid eggs are nearly oval in shape with slightly pointed end. It is often laid on underside of the leaves or young shoots of the larval food plant.

Glassy Tiger; Development of egg

The development of egg takes place for about 3-4 days (from left to right). The black head becomes clearly visible as the development happens.

Glassy Tiger; First instar caterpillar

The freshly emerged caterpillar feeds on its own egg shell as the very first meal. It has a black head capsule and whitish body with short setae (tiny hairs) all over the body. All the pairs of thoracic legs abdominal prolegs are black in color. After few hours, the body color changes to orange/brown color and two pairs of tubercles become visible on thoracic and abdominal segment. The body length changes from about 3 mm to 5 mm in this stage. 

Glassy Tiger; Second instar
1st instar caterpillar, just before moulting is shown in the upper left corner of the above image. After about 2-2.5 days the first instar moults to the second instar. 

Glassy Tiger; Second instar later in this stage
The tubercles of 2nd instar are longer and in more pointed shape than the 1st instar caterpillar.The second instar caterpillar last about 2-2.5 days reaching the body length to about 8-8.3 mm. The bottom right image of above is a freshly moulted caterpillar of third instar.

Glassy Tiger; Third instar caterpillar
The 3rd instar caterpillar has body length of about 15-16.5 mm. Additionally, it has more white and yellow spots with purplish base color and the protuberances become longer than the 2nd instar caterpillar. Third instar caterpillar lasts about 3 days.

Glassy Tiger; fourth instar
The fourth instar caterpillar resembles 3rd instar but with increased body length and darker shades. The white spots on head capsule become more clearer than the previous instars. It moults to final instar after reaching body length to about 25-28 mm. It takes about 2-3 days to last.

Glassy Tiger; Final instar caterpillar just after moulting
Fifth instar caterpillar has an irregular but thicker range of whitish yellow spots on the lower part of body. The white and yellow spots on the body becomes more larger than previous instars. This instar lasts for about 4-5 days. The maximum body length at this stage is about 37mm. 

Glassy Tiger; Fifth instar

On the last day, the fifth instar caterpillar becomes shorter in length and the body color changes from purplish brown to greenish lighter shade (as shown below).

Changes in color of the final instar caterpillar

About 12-15 hours prior to pupation process, the caterpillar ceases feeding and starts wandering restlessly on the leaves of the host plant. The body color becomes more and more lighter at this stage.  

Resting before pre-pupatory stage

It chooses the underside of matured leaf and forms a silk pad to hang on vertically in its pre-pupatory stage. The body color is yellowish green. In the next day morning pupation happens. 

The outer skin of the caterpillar gradually tears and the formation of pupa occurs for about 20-30 minutes.

Forming Pupae of Glassy tiger - 1
Forming Pupae of Glassy tiger - 2
Pupae of Glassy Tiger butterfly

After about 8-9 days development, the pupa gets matured. About 12 hours before emerge, the pupal case becomes translucent and the development of wing color is clearly visible.

Pupal stage of Glassy Tiger butterfly
Development of pupae - 1

Development of pupae - 2

The butterfly emerges early in the next day morning.

The freshly emerged butterfly hangs on its own pupal case for about 1-1.5 hours to dry its wings.

The empty pupal case

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