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Flax fungus beetle - Melanophthalma sp. 6

By N A Martin (2018)

Classification

Phylum:
Arthropoda
Class:
Insecta
Order:
Coleoptera
Superfamily:
Cucujoidea
Family:
Latridiidae
Subfamily:
Corticariinae
Scientific Name:
Melanophthalma sp. 6
  • Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
    Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
  • Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
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Common Names

Flax fungus beetle
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Taxonomic Notes

At least six species of unnamed beetles in the genus Melanophthalma (Latridiidae) are present in New Zealand and are awaiting description and naming.

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Biostatus and Distribution

The endemic Flax fungus beetle is an undescribed species that has been found feeding and breeding on fungi on leaves of New Zealand flax in Auckland. Nothing is known about its distribution and abundance.

Conservation status: Present in the Auckland region, does not appear to be endangered.

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Life Stages and Annual Cycle

In Auckland, all life stages of the Flax fungus beetle were found on underside of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) July.

Adults are typical beetles, each with six legs and hard wing covers (elytra). They are small, about 2 mm long. They are brown with the head, antennae and legs being paler than the rest of the body and wing covers. Their wings, which are longer than the wing covers, are kept safely folded up under the wing covers, except when needed for flying.

After mating the females lay small oval eggs on the fungal growth on the underside of flax leaves. Tiny white sixed-legged larvae hatch from the eggs. They have brown heads and the body turns grey. The body is covered by tufts of setae (bristles). There are several larval instars (stages) when each instar is fully grown, moults (changes skin). During moulting the skin splits on the upper, dorsal, surface and the next instar larva pulls itself out. The fully grown larva moults into a pupa its larval skin stays at the base of the pupa. The pupa is white and has wing buds. When the adult has developed inside the pupa, it emerges and the elytra and wings expand and harden.

Feeding
Adults and larvae have chewing mouth parts. They feed on the fungal growths on the underside of flax leaves.

  • Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
    Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
  • Underside of an adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
    Underside of an adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae). Image: Tim Holmes © Plant & Food Research
  • Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • Two eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Two eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • A small larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    A small larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
  • Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
  • Two images (upper side left, underside right) of a larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae): note the dark round sucker at the tip of the abdomen (right larva) used for holding on to the plant surface. Image: Tim Holmes © Plant & Food Research
    Two images (upper side left, underside right) of a larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae): note the dark round sucker at the tip of the abdomen (right larva) used for holding on to the plant surface. Image: Tim Holmes © Plant & Food Research
  • Pupa of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Pupa of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
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Recognition

There are many kinds of small beetles in New Zealand. They can only be conclusively identified by an expert. It is not known if other beetles in the genus Melanophthalma or even the family Latridiidae feed on the Flax Zasmidium leaf spot fungus. However, if small beetle larvae, pupae and adults similar to those illustrated here are found on the underside of a flax leaf in a colony of the fungus, Flax Zasmidium leaf spot, they are likely to be a member of this family of beetles.

  • Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • Four eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Four eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
  • Four pupae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Four pupae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
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Natural Enemies

No natural enemies of the Flax fungus beetle were observed. Birds, spiders and predatory insects probably prey upon them.

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Host Plants

The only known host of the Flax fungus beetle is the Zasmidium leaf spot fungus when it infests New Zealand flax. The adults and larvae feed by chewing the fungal growths on the underside of the leaves.

Table: Host plants of the Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) from Plant-SyNZ database (18 April 2018). The reliability score shows the quality of evidence for the host association (1-10, 10=high).
Common Name(s)Scientific NameFamilyReliability IndexBiostatus
Flax Zasmidium leaf spotZasmidium dianellae (Sawada & Katsuki) U. BraunMycosphaerellaceae9indigenous, non-endemic
Flax, Lowland flax, New Zealand flax, Swamp flax, Harakeke, Harareke, KōrariPhormium tenax J.R.Forst. & G.Forst.Hemerocallidaceae7endemic
  • Underside (left) and upper side (right) of New Zealand flax, Phormium tenax (Hemerocallidaceae) leaves with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae): note the fungal growths on the underside of the leaf. Image: Nicholas A. Martin © Landcare Research
    Underside (left) and upper side (right) of New Zealand flax, Phormium tenax (Hemerocallidaceae) leaves with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae): note the fungal growths on the underside of the leaf. Image: Nicholas A. Martin © Landcare Research
  • Underside (left) and upper side (right) of New Zealand flax, Phormium tenax (Hemerocallidaceae) leaves with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae): note the fungal growths on the underside of the leaf Image: Nicholas A. Martin © Landcare Research
    Underside (left) and upper side (right) of New Zealand flax, Phormium tenax (Hemerocallidaceae) leaves with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae): note the fungal growths on the underside of the leaf Image: Nicholas A. Martin © Landcare Research
  • Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Nicholas A. Martin © Landcare Research
    Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Nicholas A. Martin © Landcare Research
  • Two eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Two eggs of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • A small larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    A small larva of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
  • Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
    Two larvae of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) feeding on Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae) growing on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae). Image: Tim Holmes © Plant & Food Research
  • Pupa of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Pupa of Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
  • Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
    Adult Flax fungus beetle, Melanophthalma sp. 6 (Coleoptera: Latridiidae) on the underside of a leaf of New Zealand flax, Phormium tenax (Hemerocallidaceae) with Flax Zasmidium leaf spot, Zasmidium dianellae (Ascomycota: Mycosphaerellaceae). Image: Tim Holmes © Plant & Food Research
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Acknowledgements

Specimens of Melanophthalma sp. 6 are deposited in the NZAC and labelled NAM1207C

Rich Leschen for helpful comments.

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

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Suggested Citation

Martin NA. 2018. Flax fungus beetle - Melanophthalma sp. 6. Interesting Insects and other Invertebrates. New Zealand Arthropod Factsheet Series Number 135. http://nzacfactsheets.landcareresearch.co.nz/Index.html. Date Accessed. ISSN 1179-643X.

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