Yellow haired ladybird - Adoxellus flavihirtus
By N A Martin (2016)
Biostatus and Distribution
This endemic ladybird is found in the North and South) Islands of New Zealand. Adults and larvae feed on small insects.
Conservation status: This native ladybird is widespread, but not commonly caught.
Life Stages and Annual Cycle
The adults are small, about 3.5 millimetres long. The head, prothorax (first part of the middle body) and elytra (wing covers) are covered in short yellow-tan coloured setae (hairs). The elytra are usually dark brown or black. The head and prothorax may be the same colour or tan. The legs and antennae are tan, while the underside varies from tan to dark brown. Under the elytra is a pair of wings used for flying. The small head has a pair of compound eyes and two short antennae.
Female ladybirds lay eggs probably near infestations of prey. A larva hatches from each egg. They are covered with short hairs. The three pairs of legs are used for walking. As the larva grows, it moults (changes skin). There are four larval instars (stages). The last instar is grey on its dorsal (top) side with the short pale setae grouped on tubercles. Some tubercles on abdominal segments 1, 5 and 6 are pale. Also there is white wax between some of the setae. The underside of the larvae is white to pale grey. The small head is brown. When the fourth larval instar is fully grown, it attaches itself to a sheltered place on a plant and moults into a pupa. The white to pale grey pupa is covered with short setae. The moulted larval skin remains at the base of the pupal abdomen. Adults hatch from pupae and mate. The length of time of each life stage depends on temperature, being shorter at higher temperatures.
There have not been any detailed observations of the annual cycle of this ladybird in New Zealand. Adults and larvae have been only been found associated with insect prey in spring and summer.
Walking and flying
Both adult and larval stages of this yellow haired ladybird have three pairs of legs that can be used for walking. Adults have wings and can fly.
The adult and larval ladybirds eat psyllids, mealybugs, aphids and scale insects. The jaws are the primarily structures used for holding and chewing the prey. Legs do not appear to be used for holding food.
Some adult yellow haired ladybirds are easily recognised by their tan coloured head and prothorax, and their short dense tan coloured setae (Hairs). For other adults, expert help is needed.
The larvae are distinctive, but because little is known about the appearance of other native ladybird larvae, larvae of the yellow haired ladybird cannot be identified with certainty. The last instar larva is grey on its dorsal (top) side with the short pale setae grouped on tubercles. Some tubercles on abdominal segments 1, 5 and 6 are pale. Also there is white wax between some of the setae. The underside of the larvae is white to pale grey. The small head is brown.
No natural enemies of the yellow haired ladybird are known in New Zealand. They are probably preyed upon by birds, spiders and predatory insects.
Little is known about the prey of the yellow haired ladybird. Adults and larvae have been found four times associated with prey, the pittosporum psyllid, Trioza vitreoradiata and adults reared from the larvae that fed on the psyllid. Larvae were found on leaves of Astelia banksii with colonies of Long-fringed Astelia mealybug, Rastrococcus asteliae (Maskell, and reared to adulthood. A larva was found on a young frond of Sickle spleenwort, Asplenium polyodon, heavily infested with green fern aphids, Micromyzella filicis. The larva fed on the aphids, but was not reared. It is likely that this ladybird feeds on a wide variety of small insects. A larva was found feeding on the Spotted sixpenny scale, Ctenochiton paraviridis, but was not reared. It is likely that this ladybird feeds on a variety of small insects, especieally Hemiptera.
|Scientific Name||Common Name||Classification||Reliability Index||Biostatus|
|Ctenochiton paraviridis Henderson & Hodgson, 2000||Spotted sixpenny scale||Hemiptera: Coccidae||9||endemic|
|Micromyzella filicis (Van der Groot, 1917)||Green fern aphid||Hemiptera: Aphididae||9||adventive|
|Rastrococcus asteliae (Maskell, 1884)||Long-fringed Astelia mealybug||Hemiptera: Pseudococcidae||10||endemic|
|Trioza vitreoradiata (Maskell, 1879)||Pittosporum psyllid||Hemiptera: Triozidae||10||endemic|
Diverse habits of ‘ladybirds’
Not all ladybirds eat insects; 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).
Chris Winks for identification of the ladybird.
The New Zealand Institute for Plant & Food Research Limited (Plant & Food Research) for permission to use photographs.