Major Group: Insecta
Order: Coleoptera
Family: Curculionidae |
Descriptive Features:
Adults
head with long rostrum, snout-like
elbowed antennae, antennal club compact, 3-segmented
antennal insertions exposed from above
prothorax without notopleural sutures, ventral portion of the notum, (hypomeron) on each side joined directly to the sternum by notosternal suture
pleuron reduced and concealed
abdomen with more than 3 ventrites
intercoxal process on ventrite 1 truncate
size: <5mm
Larvae
labial palps 2-segmented
frontal arms not reaching mandibular articulations (ending at antennal insertions)
legs absent
abdominal spiracles usually forming spine-like processes
tergum 3 with 3 transverse plicae
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Curculionidae larva |
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Curculionidae adult |
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Taxonomic Checklist: Subfamilies are included here as there is no key to ALL genera.
Subfamily Genera
Bagoinae
Bagous australasiae Blackburn
Erirhininae
Cyrtobagous 2 species (introduced from South America)
Echinocnemus ? species
Neochetina eichhorinae Warner (introduced from Argentia via Florida)
Neohydronomus pulchellus Hustache (introduced from Brazil)
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Distribution: Australia wide
Introduced species are only in Queensland (at 1992)
Sensitivity Rating: SIGNAL grade 2
Functional Feeding Group: shredders |
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Wakool River at Kyalite, NSW |
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Ecology: Curculionidae is a large terrestrial family with only a few species occurring in aquatic situations and these are not truly aquatic animals.
Instream habitat: Typically, it is only the adults that are collected from aquatic habitats. However, for the more common semi-aquatic genus, Bagous, both adults and larvae live in stagnant or slow moving water. The adult beetles crawl amongst submerged water plants while larvae live inside air-filled stems of aquatic plants.
Feeding ecology: Adult and larval curculionid beetles are herbivorous shredders. Adults feed on leaves while larvae tunnel into petioles, crowns and stems feeding on the internal plant tissues. The feeding activity of the larvae usually results in rotting of the surrounding plant tissues and can result in plant death
Habit: Australian curculionid adults have little adaption to aquatic life. However, the introduced species, Neochetina eichhorniae, do possess specialized aquatic adaptations including hydrofuge hairs and scales. All adults are typically nocturnal and are attracted by light.
Life history: Australian semi-aquatic species have not been extensively studied, so much of the published information is surmised from overseas studies. Adults mate on emergent portions of water plants. The unusual rostrum of adult Curculionidae species is thought to be used to bore into plant tissue to form an egg cavity. Adults lay their eggs within plant stem tissue near leaf joints. Larvae hatch out in three to four days, followed by three to four larval instars each lasting several days. The third instar larvae then leave the water plant to pupate in dry soil. For New Zealand terrestrial species, the main period of adult emergence is late winter – early spring. Early spring is the main period of reproductive activity then adult population densities decline rapidly during summer. |
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Information Sources: Zimmerman 1994, Williams 1980, Lawrence 1992, Lawrence & Britton 1991, Gooderman & Tsyrlin 2002, Hendrich et al. 2004, Barratt et al. 2000
Key to Genera: Zimmerman 1994 (Erirhininae larvae)
Key to Species: Zimmerman 1994 (Cyrtobagous larvae) |
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