Ladybird (Hadda Beetle, 28 spotted) Henosepilachna vigintioctopunctata
Species: H. vigintioctopunctata
Binomial name: Henosepilachna vigintioctopunctata
Synonyms: Coccinella 28-punctata, Coccinella sparsa, Epilachna gradaria, Epilachna territa, Epilachna vigintioctopunctata, Epilachna sparsa.
Common names: Hadda Beetle, Potato ladybird, 28-spotted potato ladybird, 28 spotted ladybird
Henosepilachna vigintioctopunctata is a adventive plant eating ladybird native to south-eastern Asia, primarily India, but has now been accidentally introduced to other parts of the world, including New Zealand. It was first detected in January 2010 in Auckland and it is now considered established in New Zealand. The adult beetle can fly up to 50 metres and it can also be spread by the movement of plant material.
us (nightshades) crops and causes damage to agricultural crops such as potatoes, pumpkin, turnips, radishes, beans and spinach. It also harms native plants such as poroporo (Solanum laciniatum). Both the beetles and larvae damage the foliage. The adults usually feed on the upper surface of leaves, while the larvae feed on the leaves underside. They scrape away the leaf surface from the main leaf’s vein leaving irregular holes. The damage from heavy feeding gives leaves a distinctive lace-like appearance. Both adults and larvae feed on the host plants unlike most other ladybirds who are generally predators.
The adult beetle’s body (7-10mm) is hemispherical, smooth and is a yellow orange colour, the colour can vary. The head, prothorax (first part of the middle body) and elytra (wing covers) are covered with short fine hairs. The elytra are covered with 28 spots. The size and shape of the spots is variable, but only the pairs of spots by the mid line of the second and fourth transverse rows may join each other. The underside of the ladybird is orange-brown and black. There are three pairs of orange-brown legs. Under the elytra is a pair of wings used for flying. The small head is mainly pale orange and has a pair of compound eyes and two short antennae. The antennae are orange-brown.
After copulation female lays about 120-180 cigar shaped, yellowish coloured eggs. They are laid in an erect position in clusters of 45 (average) on the lower surface of the leaves. The larva hatches in 3- 4 days in summer months and in 4-9 days in winter. The hatched larvae are pale yellow and are covered with tubercles with long seta. The body remains yellow and the tergites, tubercles, setae and three pairs of legs become dark grey. A fully grown larva measures about 8 mm in length. Larvae usually feed on the underside epidermis of the leaves, leaving the epidermis on the top side of the leaf intact.
The larval period lasts for 9-18 days during which it passes through four different stars before it pupates. The larva changes into pupa on leaf’s surface or on a stem or at the base of the plant. During pupation the larva attaches its last abdominal segment to the surface of host plant by means of sticky secretion. The pupal period lasts for 3-6 days but in certain cases it may extend further. The life cycle is completed in 17-18 days in summer but in winter it may prolong up to 50 days. There are about 7-8 generations during March-October. In winter the adult beetles hibernates in the soil or within dry leaves on the ground. The adults are voracious eaters and live up to one to two months.
The size and arrangement of spots and presence of short hairs covering the upper side of the body make the adult hadda beetle easy to recognise. However, it is superficially like the Large spotted ladybird, Harmonia conformis (Boisduval, 1835). The most reliable difference is the arrangement of black spots along the mid line, where the two elytra join. In the Hadda beetle, only the two spots in the second and fourth transverse rows may touch each other, whereas in the large spotted ladybird, it is the two spots in the first and third transverse rows. The recently arrived Harlequin ladybird, (Harmonia axyridis (Pallas, 1773)) is very variable and may have many black spots on an orange background. The pronotum is usually black and white, with the black marks that are M-shaped when viewed from above.
For more images of adults and larvae visit: http://www.brisbaneinsects.com/brisbane_ladybirds/28-spotted.html