Silky Lacewings (Psychopsidae)

I spend a lot of time trying to explain to people just how mind-numbingly diverse invertebrates can be.

And they are; take the lacewings - quite small, as insect orders* go, but still have over 600 species recorded from Zambia or a neighbouring country (based on information from the Lacewing Digital Library, an excellent resource that I probably rely on far too heavily).

So it's always pleasing to realise that I have encountered every member of a specific clade that enters the country, whether it's all the subspecies of a species, all the species of a genus or - in this case - all the members of the family.

Even if that family is the Psychopsidae, one of the least represented Neuropteran families in the continent with only eight species entering Africa, and only two likely to occur in Zambia (i.e. recorded in Zambia, or in multiple disjunct, bordering countries, in areas of comparable climate.

Before I bore you too much with endless text, here's one of them:

Silveira marshalli (McLachlan, 1902); came to lights on an unnamed tributary of the Luangwa. 

These eight species in three genera are actually a rather hefty share of the global diversity; both Australia and Asia have only a single genus each (although Australia's Psychopsis contains half of the global species).

They are extremely distinctive lacewings, at least within the region, instantly separated from all other lacewings by their broad, hairy wings; while some 'green' lacewings (Chrysopidae) and the Osmylids (no common name) are rather broad shouldered, none are quite so dramatic as these; they also tend to have rather longer antennae, and their bodies extend more noticeably in front of the wings.

Most are associated with woodland, where they have been suspected to pre-powder their eggs with vegetable matter, and fire them into leaf-litter while in flight (for more on that - and a general overview of the family - see Oswald, 1993); these presumably hatch into the usual, hyper-predatory little monsters that lacewing larvae usually are.

Formally, only one species is recorded from Zambia; but given that Zambia's predominant natural habitat is Miombo woodland (accounts vary as to whether this is a fire-dominated moist savannah, or is a type of subtropical deciduous forest currently massively degraded by man-made fires), it wasn't a stretch to assume that Silveira marshalli (McLachlan, 1902) - recorded from Botswana, Zimbabwe, South Africa and Zaire - would be present; it is, and comes to lights in numbers in forested parts of Eastern and Muchinga provinces.

As for the other, Zygophlebius leoninas, Navás, 1910 - easily the most widespread African species, probably the most widespread species in the entire family (although as you can read in Oswald, 1994, there is a bit of a mess where it comes to records of this and the genitally-distinguished Z. zebra (Brauer, 1899) - I'd really like to be able to credit its appearance at a kitchen window in the increasingly developed Chongwe district to my ongoing tree-planting (and native-tree-encouraging) efforts, rather than the more likely conclusion that it's just another species that is slowly disappearing as every acre of ground is agriculturally exhausted and covered in concrete.

On that somewhat bleak note, here it is:

Zygophlebius leoninus Navás, 1910 in Chongwe District, Lusaka, Zambia. 

*Main taxonomic rankings, in order from largest to smallest: Domain (e.g. Eukaryota); Kingdom (e.g. Animalia); Phylum, (e.g. Arthropoda); Class (e.g. Insecta); Order (e.g. Neuroptera - lacewings); Family (e.g. Psychopsidae - Silky Lacewings); Genus (e.g. Silveira or Zygophlebius) and Species (e.g. Silveira marshalli)