Epiphryne verriculata

Epiphryne verriculata, the cabbage tree moth, is a moth in the family Geometridae. It is found only in New Zealand, and only feeds on the native cabbage tree (Cordyline australis); its wings are patterned to camouflage it against dead cabbage tree leaves.

Epiphryne verriculata
Female
Male
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Lepidoptera
Family:	Geometridae
Genus:	Epiphryne
Species:	E. verriculata
Binomial name
Epiphryne verriculata (Felder & Rogenhofer, 1875)
Synonyms[1]
Synonymy Cidaria verriculata Felder & Rogenhofer, 1875 Panopoea verriculata (Felder & Rogenhofer 1875) Pancyma verriculata (Felder & Rogenhofer 1875) Venusia verriculata (Felder & Rogenhofer 1875)

Taxonomy

Epiphryne verriculata was first described by Baron Cajetan von Felder, Rudolf Felder & Alois Friedrich Rogenhofer in 1875 under the name Cidaria verriculata.^[2][3] The species was later moved to the genus Panopaea in 1884, then to Pancyma in 1886 and then to Venusia in 1917, with these changes all being made by British entomologist Edward Meyrick.^[3] In 1964, the species was finally moved from Venusia to the genus Epiphryne, in which it currently remains.^[4] The type specimen is stored in the Natural History Museum of London.^[3] They are commonly referred to as "cabbage tree moths".^[5]

Description

A cabbage tree moth on a leaf of New Zealand flax (Phormium sp.)

The wingspan of the adults is about 3.8 cm in length. The wings are typically a light brownish colour, although there is some variation. Running along the wings are brownish parallel lines. On the second pair of wings, the lines are somewhat thicker in the middle, with more space on either side of them. The abdomen also has a brown line pattern, which smoothly aligns with the pattern on the wings. With this line pattern, the moths are able to camouflage themselves on the dead leaves of Cordyline trees.^[6]

Larva

Larvae

The larvae are overall coloured green. The head is yellowish-brown with pairs of dark stripes at the sides and near the top of the head. The segments of the body each have four black spots on the upper surface and three on the side, except for the third and fourth segments which just have a single row of spots. Their bodies also have dark lines running down their sides. When fully grown they are roughly 2.5 cm in length.^[6]

Eggs

The eggs are 0.75-0.79 mm in length and 0.58 mm wide. They have an oval, almost cylindrical shape and are somewhat transparent. The surface of the eggs have a series of hexagonal and pentagonal reticulations which are around 0.04 mm in diameter. Although they are bright green when laid, a few days later, the eggs become a mix of red-brown and bright green.. As the eggs continue to mature, the red-brown areas become bigger until the egg is red.^[7]

Distribution and habitat

This moth is endemic to New Zealand and is very common, being widely distributed throughout the country.^[8][9] Its favoured habitats are wetland and native forest, but it can be found in urban parks and gardens, as cabbage trees are commonly grown in cultivation.^[9]

Life history

Leaf damage from cabbage tree moth caterpillars

The eggs are laid on the underside of leaves in neat parallel rows in autumn and spring.^[8] After approximately 14 days the eggs hatch and the caterpillars emerge.^[1] At night caterpillars feed on the new and unopened leaves of Cordyline australis; their flattened bodies allow them to squeeze in amongst the developing leaves.^[10][1] The caterpillars create a characteristic pattern of damage, initially making holes and dark channels along the leaf and, as they grow, notches in the leaf edge.^[11] As the leaf opens and grows the notches likewise grow and become more noticeable.^[10] The larvae pupate either on the cabbage tree in crevices or dead leaf bases or on the ground underneath.^[11] Adults can be seen from spring to late summer (October to May).^[9] The moth sits with its body perpendicular to the leaf's long axis and wings pressed up against the leaf, its markings lining up with the veins. If disturbed, the will only fly a short distance before finding another dead brown leaf to settle on, avoiding the green fresh leaves.^[10] Although attracted to light, the adult moth is inconspicuous when resting by day on cabbage tree leaves, and this camouflage helps protect it from predators.^[12]

Length of phases to reach adulthood^[13]

Phase	Duration in days
Egg	15-22
Larva 1st instar	15
Larva 2nd instar	13
Larva 3rd instar	13
Larva 4th instar	12
Larva 5th instar	21
Pupal cocoon building	2
Larva living in pupal cocoon	4-5
Pupation	50 (in winter)

Predators and parasites

They are preyed upon by numerous other insects. The larvae of the hoverflies Melangyna novaezelandiae and Allograpta ropala are known to prey upon Epiphryne verriculata larvae. Cermatulus nasalis, a species of shield bug, has also been recorded preying upon the larvae. The tachinid Pales feredayi are endoparasitoids of the moth larvae. In their larvae stage, they live and develop in the moth larvae before emerging as an adult when the moth larvae undergoes pupation.^[14] The braconid wasps Aleiodes declanae and Meteorus pulchricornis are also endoparasitoids of the moth larvae, with the latter species being introduced to New Zealand.^[15]

Conservation status

Epiphryne verriculata is common throughout New Zealand and not regarded as threatened.^[1]