Saturday, January 24, 2015

The backyard as laboratory and workshop series:The Enigmatic Papilio Butterfly

Introducing an insect to a toddler  
Dr Abe V Rotor 

Citrus Papilio butterfly (Papilio demoleus) caterpillars appear like bird droppings, from which it got its name "bird dropping caterpillar." 


 

Mackie 2, is introduced to entomology, the science of insects, in a series of photographs. Note her expression as she gathers courage, and finally touches and caresses the caterpillar.  Photos by the author, at home in QC

 
Complete life cycle of the citrus swallowtail butterfly (Papilio demoleus). 
The insect undergoes four stages: egg, caterpillar (four instars), pupa, and adult (butterfly)
Note the transformation of the bird dropping caterpillar (first instar) into green growing up enormously (2nd and 3rd instars), until it is ready for the next stage.  Here it secures itself with a single stout thread in a 45 degrees position with head down. The pupa transforms from green to brown.  After a week or so, it emerges into a beautiful butterfly. 

The butterfly's metamorphosis is dramatically described in an illustrated book, Hope for the Flowers, by Paulas. There's a clarification though; the  pupa of a butterfly is naked, in the sense that it is not enclosed in a silk cocoon, unlike that of the moth and the skipper - also a Lepidopteran that exhibits dual characteristics of both its relatives.  Skippers are active at dusk (crepuscular); whereas butterflies are diurnal, and moths nocturnal. The classical example of a moth is the silkworm, Bombix mori, while that of a skipper is the Nymphalid, falsely identified as butterfly. 
Bird dropping first instarstage

 Top left, clockwise: closeup of bird dropping caterpillar (1st instar).  The caterpillar turns green with camouflage design, and is  most destructive, feeding on leaves of citrus (2nd and 3rd instars).  Full grown caterpillar about to pupate; early stage pupa, which gradually turns brown as it approaches metamorphosis.    

Dorsal color and pattern of the citrus Papilio demoleus showing a pair of false eyes, which scares a would-be predator.  
Close-up of the pair of false eyes highlighted by red shade around the "eyeballs."    
 
Resting position of Papilio demoleus showing the ventral side of its wings as differentiated from the dorsal color and pattern. Such difference is mistaken for two species. Disguise pattern and coloration protects the butterfly from would-be predators. The same principle of differentiation helps in the species' survival.   
                       
                  Papilio demoleus mating, showing ventral side of their wings,  
The dorsal side is partly visible. Acknowledgement: photos of the 
adult Papilio and its stages wete sourced from the Internet Wikipedia

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