01 February 2010

Chrysopidae – Green Lacewings

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Chrysopidae – Green Lacewings

Chrysopidae is the best known and largest of the lacewing families, with around 2,000 species distributed worldwide. In Australia, the Australian Faunal Directory lists 59 species spread over 16 genera, most restricted to the Queensland/NSW region, but some are represented in all States. In Western Australia there are 14 known species of which 6 occur in the southern district (not necessarily Esperance).

There are two individuals shown above; one has a head/body length of 1.2 cm (1/2”) and the other 1.8 cm (3/4”) in length, which may only be a size variation, or it may indicate a different gender/species. This is because most lacewings are very similar and notoriously difficult to tell apart, with some distinguished purely by their mating calls. Most adult lacewings will feed on blossom nectar and pollen, with some also taking small invertebrates.

Green Lacewings are well known for being attracted to house lights, so are reasonably easy to determine if they are common or not, but in the sandy Esperance heath they are rarely seen. This may reflect the dry open habitat not being suited to the highly mobile larvae that hunt aphids and small invertebrates, which tend to favour annual and ephemeral herbaceous vegetation. This type of soft tissue vegetation is locally only plentiful during winter/spring, thereby limiting the supply of suitable prey throughout the year and so denying the Green Lacewing larvae sustenance, particularly during the summer/autumn period. On the other-hand, the SW corner of the State is a much friendlier place, with cooler conditions, higher rainfall, better soils and a tall tree cover, thereby providing a more compatible environment to support a greater number of lacewing species. Locally the few encountered have been during August and September.