Paralaea beggaria

Paralaea beggaria (Guenee, 1857)
(one synonym is : Stathmorrhopa aphotista)
NACOPHORINI , ENNOMINAE , GEOMETRIDAE

Don Herbison-Evans ( donherbisonevans@yahoo.com )
&
Stella Crossley

(updated 26 February 2005)

(Photo: courtesy of Merlin Crossley)

When young, these Caterpillars are prettily striped. The green dorsal surface has broad dorsal and ventro-lateral stripes that are black and dotted with white. The sides are creamy yellow with a brown lateral stripe. The ventral surface is green. The brick-red head adds to the striking appearance of the Caterpillar.

The mature Caterpillars have a number of colour forms. Most have a green dorsal surface and blue-green ventral surface, which are separated by a yellow lateral line, and have a light yellowish-green head with a mauve crown. The various colour forms have additional yellow, brown and/or purple straight or wavy stripes.

The ventral prolegs on abdominal segment six are complete, but those on segment five are reduced, and those on segments four and three are represented by small bumps. The anal prolegs splay out over the substrate in a fish-tail shape.

The Caterpillars have been known to outbreak and defoliate large areas of :

Gum Trees ( Eucalyptus, MYRTACEAE ),

attacking a number of different Eucalyptus species. The early instars seem to prefer younger leaves.

Several behaviours are characteristic of these Caterpillars. At rest, young Caterpillars lie along the leaf midrib, or stand off the midrib, like a stick. Mature Caterpillars instead tend to cling to the leaf edge. Before changing its skin, a Caterpillar lays down a silken pad, and rests on this in a 'U' shape.

The Caterpillar grows to a length of about 3.5 cms. The pupal stage can last for up to seven months.

(Photo: courtesy of Merlin Crossley)

The adult moth has dark grey fore wings with a dark spot in the middle. The hind wings are silvery grey. At rest, the moth wraps its fore wings around any object to which it clings, giving the body extra support. The moths have a wingspan of about 5 cms.

The eggs are laid in a distinctive formation, at a slight angle to the substrate, and slightly overlapping each other, like roof shingles. The eggs are initially duck-blue, changing later in colour to green then cream and finally transparent. They appear to hatch after rain.

This genus has recently been studied by Catherine B. Young.