INTERESTING INSECTS

By N A Martin (2016, revised 2018)

Hadda beetle, 28-spotted ladybird, 28-spotted potato ladybird

Coccinella 28-punctata Fabricius, 1775

Coccinella chrysomelina Fabricius, 1775

Coccinella sparsa Herbst, 1786

Epilachna gradaria Mulsant, 1850

Epilachna territa Mulsant, 1850

Epilachna sparsa (Herbst, 1786)

Henosepilachna vigintioctopunctata (Fabricius, 1775)

Changes to the generic placement of Hadda beetle have been proposed. The two names currently being used are Epilachna and Henosepilachna. This factsheet is using the older name.

This adventive plant eating ladybird is from South East Asia. It has spread to Australia and South America. In January 2010, I found a hadda beetle in an Auckland Park overlooking the port. A specimen had been collected a few years earlier, but not recognised. In 2010, the distribution of the beetles was substantially reduced. Hadda beetles are still restricted to urban Auckland, but are gradually spreading beyond their 2010 range.

Conservation status: This adventive ladybird feeds on plants in the family Solanaceae and damages crops such as potatoes and harms native plants such as poroporo, Solanum laciniatum.

The orange and black spotted adults are about 7-10 millimetres long. 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 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.

Female ladybirds lay clusters of yellow eggs near infestations of prey. A larva hatches from each egg. There are four larval instars (stages). As the larva grows, it moults (changes skin). The newly hatched larva is pale yellow and covered with tubercles with long seta. The body remains yellow and the tergites, tubercles, setae and legs become dark grey. There are three pairs of legs. Larvae also use the tip of the abdomen for holding onto the substrate on which they are walking.

The tip of the abdomen also holds the larva to the surface during moulting both to another larval instar and to a pupa. When the fourth larval instar is fully grown, it attaches itself to a sheltered place on a plant. The spiny skin of the larva remains attached to the base of the pupa. The pupa is covered in black setae. It is black except for the pale inter-segmental membranes. There are prominent white tubular abdominal spiracles, openings to the air ducts (trachea). Adults hatch from pupae and mate. The length of time of each life stage depends on temperature, being shorter at higher temperatures.

Annual cycle

The ladybird overwinters as adults. In spring adults locate host plants and lay eggs. There are several generations per year in Auckland.

Walking and flying

Both adult and larval stages of this ladybird have three pairs of legs that can be used for walking. Larvae also use the tip of the abdomen for holding onto the substrate. Adults have wings and can fly.

Feeding

The adult and larval ladybirds feed on plant leaves. The larvae chew distinctive channels in one side of the leaf, leaving the epidermis on the other side of the leaf intact.

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA0]

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9H]

Underside of an adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9I]

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9K]

Eggs of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9M]

Eggs of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9N]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) larvae hatching from eggs. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9U]

Eggshells of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the signs of feeding on the leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9W]

Young larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9X]

Newly hatched larvae of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9V]

Underside of a young larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9Y]

Larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA1]

Mature larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA3]

Leaf of Solanum nigrum (Solanaceae) with feeding damage and faeces of larvae of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AAC]

Prepupal larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AAA]

Just moulted pupa of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the moulted larval skin. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA5]

Pupa of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the moulted larval skin. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA7]

Pupa of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the moulted larval skin and the white tubular abdominal spiracles. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA8]

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.

The ‘bristly’ larvae and pupae of the hadda beetle are also distinctive. The feeding damage to leaves also allows the recognition of the presence of hadda beetles.

Adult hadda beetle, Epilachna vigintioctopunctata (Fabricius, 1775) (Coleoptera: Coccinellidae), yellow arrow points to the dark spot on the mid line and the green arrows point to the two pairs of spots in front and behind. The head, prothorax and elytra are covered by dense short hairs. Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9G]

Typical adult large spotted ladybird, Harmonia conformis (Coleoptera: Coccinellidae), yellow arrows point to the two dark spots on the mid line. Creator: Tim Holmes. © Plant & Food Research. [Image: 2AAY]

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), about 7-10 mm long. Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9F]

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9L]

Adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the short dense hair on the elytra, pronotum and elytra. Creator: Tim Holmes. © Plant & Food Research. [Image: 2A9J]

Underside of an adult of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AAD]

Two small larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9Z]

Larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA1]

Mature larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA3]

Pupa of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae), note the moulted larval skin. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA7]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding damage on leaf of Solanum nigrum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9R]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding damage on leaf of Solanum nigrum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9P]

No natural enemies of the Hadda beetle are known in New Zealand.

Adult and larval hadda beetles feed on plants in the Solanaceae (potato family). Host plants include crops such as potatoes, tomatoes and eggplant. It also feeds on weeds such as black nightshade, Solanum nigrum, and could provide some biological control of the weed. However, it also feeds on native plants such as poroporo, Solanum laciniatum and Small-flowered nightshade, Solanum nodiflorum.

Only adults have been found feeding on Woolly nightshade, Solanum mauritianum.

Larvae feeding on leaves make distinctive short parallel grooves on the underside. These areas of grooves may form holes in the leaves. Adult feeding can also result in ragged holes in leaves.

Mature larva of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA3]

Newly hatched larvae of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9V]

Leaf of Solanum nigrum (Solanaceae) with feeding damage by larvae of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA2]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf of Solanum nigrum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9S]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf of Solanum nigrum (Solanaceae), underside of leaf. Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2A9T]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding on leaf of Solanum nigrum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2AA4]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding damage on the upper side of leaves of Poroporo, Solanum laciniatum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2KK8]

Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae) feeding damage on the underside of leaves of Poroporo, Solanum laciniatum (Solanaceae). Creator: Nicholas A. Martin. © Plant & Food Research. [Image: 2KK9]

Leaf of Velvet nightshadeSolanum chenopodioides (Solanaceae) with feeding damage by larvae of Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). © All rights reserved. [Image: 2S4V]

Leaf of Woolly nightshade Solanum mauritianum (Solanaceae) with feeding damage by adult Hadda beetle, Epilachna vigintioctopunctata (Cleoptera: Coccinellidae). © All rights reserved. [Image: 2S4W]

Removing alternative weed host plants

If you are in an area of Auckland with hadda beetle, you can reduce your risk to susceptible crop plants by removing weeds such as black nightshade, Solanum nigrum, from your garden and as much of the surrounding area as possible.

Physical control

When you see adults and larvae on your plants, remove and destroy them. Look out for the distinctive feeding damage to leaves and search carefully for any larvae or adults.

Diverse habits of 'ladybirds'

Many ladybirds eat insects and some feed on mites. Other species eat plant leaves and are pests especially in some tropical countries, whereas other ladybirds feed on fungi. One of these, Illeis galbula (Mulsant, 1850), from Australia feeds on powdery mildew fungi. In New Zealand it is common on pumpkins and other cucurbits, plants that are commonly infected by powdery mildews. A plant feeding ladybird, hadda beetle (Epilachna vigintioctopunctata (Fabricius, 1775)) recently established in Auckland feeds on plants in the Solanaceae (potato family).

Plant-SyNZ: Invertebrate herbivore-host plant association database. plant-synz.landcareresearch.co.nz/.

The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research) for permission to use photographs.

Alan Flynn for information about the insect.

1 November 2018. NA Martin. Changed symbol used for apostrophes.

1 August 2018, NA Martin. New host plant and photos added.

1 August 2017, NA Martin. Added new photos of leaf damage to Poroporo.