Butterfly Biodata:
Genus: Zographetus Watson, 1893
Species: panormus Eliot, 1959
Wingspan of Adult Butterfly: 30-32mm
Caterpillar Local Host Plant: Vitex pinnata (Lamiaceae/Labiatae, common names: Leban, Malayan Teak, Vitex, Halban, Leban Buas, Leban Papa, Leban Tandok).
Physical Description of Adult Butterfly:
On the upperside, the wings are dark brown with hyaline sub-spaical yellowish spots on the forewing. On the underside, the hindwing discal area is yellowish in the male and the entire underside is mostly yellow in the female. Dark brown discal and post-discal spots are also featured on the hindwing. Both wings have brown marginal bands. The annennae of the male are broadly whitened just after the apiculus (the hooked tip at the end of the club antenna), while those of the female has a much reduced white patch at the tip of the apiculus.
A short video clip showings the adult stage of the Spotted Flitter.
Field Observations of Butterfly Behaviour:
The Spotted Flitter is rare in Singapore. Its occasional sightings range from urban parks and gardens to forested areas in the nature reserves. The adults are usually observed in the early morning hours of the day or in deep shady areas during later hours. The adults are fast flyers as is typical of most skipper species.
Early Stages:
Thus far only one local host plant, Vitex pinnata, has been recorded for the Spotted Flitter. This plant is a tree of the family Lamiaceae, and it can grow up to a height of about 25m. Typically caterpillars of the Spotted Flitter are found on young plants 1 to 2m in height. The leaves of the Vitex pinnata are palmately compound with sessile leaflets. The caterpillars of the Spotted Flitter feed on the mature leaves in all instars, and live in leaf shelters constructed at leaf edge.
The eggs are laid singly on a leaflet of the host plant, typically on the upperside. Each dome-shaped egg is dark red with 14 to 16 whitish longitudinal ridges, and has a beige brown pitted donut-shaped cap. The egg is rather large with a diameter of about 1.4-1.5mm.
It takes about 6 days for the egg to hatch. The fully developed egg is orange in colour with the back head capsule is visible through the egg shell.
The young caterpillar eats just enough of the shell to emerge. Unlike most other butterfly species, the newly hatched of the Spotted Flitter does not proceed to devour the empty egg shell. The newly hatched has a length of about 2.5mm. Its orangy body is cylindrical in shape with a small number of very short and tiny dorso-lateral and lateral setae. There is a tuff of moderately long setae on the posterior segment. Its head is dark brown with a black collar lying behind it on the prothorax.
After emerging from the egg shell, the newly hatched caterpillar constructs its first leaf shelter, typically at the nearby leaf edge. With diligent lamina cutting and use of silk threads, the leaf shelter gradually takes on a gobular appearance, a rather unique shape for leaf shelters of skipper species. The 1st instar takes a total of 3.5-4 days to complete with body length reaching about 4.5mm.
The body of the 2nd instar caterpillar is dark orangy brown with a dark brown head. The body and the head are covered with numerous tiny whitish setae. The dark brown collar on the prothorax is still present. This instar lasts a total of 3.5-4 days with the body length reaching up to 6.5mm.
The 3nd instar caterpillar resembles the 2nd instar caterpillar closely. The body takes on a more distinctly mottled appearance as there are whitish specks at the base of each tiny setae careting the body surface. This instar lasts about 4-5 days with the body length reaching up to about 9.5mm.
The 4th instar caterpillar resembles the 3rd instar caterpillar closely. Its body colour ranges from yellowish brown to orangy brown. To accommodate the increased body size, the caterpillar enlarges its leaf shelter with more skillful cutting of lamina and use of silk threads. This instar lasts 6-8 days with the body length reaching up to 14.5mm.
The 5th instar caterpillar does not differ much from the 4th instar caterpillar, except for the more distinctively mottled appearance due to the increased size of the numerous whitish spots covering the body surface.
The 5th instar takes about 8 days to complete with the body length reaching up to 28-29mm. In the last 2 days of this instar, whitish powdery substance appears on the ventral surface of the caterpillar. The caterpillar also abandon the brownish gobular leaf shelter, and proceed to a leaflet to start constructing the pupation shelter. It also nearly sever the petiole and midrib at multiple points and secure the resulted parts with silk threads. The leaf shelter is formed by cutting the leaf lamina to create two adjacent folds and having two ends of a fold tucked in to form an almost enclosed space. The completed leaf shelter roughly takes on a submarine shape.
Within the pupation shelter, the body has its color changes to pale yellowish brown. The caterpillar also excrete a fair amount of whitish powdery substance which cover its body as well as the inner wall of the shelter. This prepupatory phase lasts for 1-1.5 days.
Pupation takes place within the pupation shelter. The resultant pupa is secured to the inner wall of the shelte with a cremastral attachment. The pupal body is brown in the thorax and wing pad areas, but yellowih brown in the abdomen. With the pupaion almost closed, the shedded head and exuvia of the 5th instar are left at the posterior end of the pupa. Length of pupae: 17-18mm.
After about 8 days, the pupa becomes mostly dark brown with the wing pad areas in darker brown and a glimpse can be caught of the spots present on the forewing upperside. Eclosion takes place the next day.
A male Spotted Flitter emerges from its pupal case.
Another male Spotted Flitter emerges from its pupal case.
References:
- [C&P5] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, G. and N. van der Poorten (Eds.), 5th Edition, Malayan Nature Society, 2020.
- Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
- A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2nd Edition, 2015.
1 comment:
Fantastic account of the development of this skipper. Keep up the good work!
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