Archivos de diario de marzo 2019

26 de marzo de 2019

Micraspis flavovittata Lady Beetle Discoveries

This article first appeared in the Field Nats News No. 295, Newsletter of the Field Naturalists Club of Victoria Inc (FNCV), with modifications for iNaturalist and webification.

Lady beetles are scientifically classified in the Coccinellidae family of the insect order Coleoptera (beetles). Although there are many cryptic and tiny species, we are all familiar with the colorful beetles of around 5mm in length occasionally sighted clambering around in our gardens. The easily recognizable species usually belong to the subfamily Coccinellinae but there are look-alikes in different families altogether, particularly within leaf beetles (Chrysomelidae) — visual mimicry is not uncommon in beetles. Lady beetles can best be distinguished from others by having relatively short antennae.

According to the 1,708 Coccinellidae records for Victoria currently available on the Atlas of Living Australia the most abundant lady beetle species in our state is Harmonia conformis, which goes by various common names including “large spotted ladybird”. This native is a predatory species feeding on such things aphids and other plant pests so is very beneficial to have around. It has text-book orange base coloration with relatively uniformly sized black spots.

However not all lady beetles are predatory. Another of the most common species in Victoria is Illeis galbula. It is smaller than Harmonia conformis and distinctively yellow and black. As its common name of “fungus-eating ladybird” suggests, it feeds on mould sometimes found on plants and often found crawling in our vegetable patches on cucumber and pumpkin leaves.

One lady beetle very few people have encountered is Micraspis flavovittata (it currently doesn’t have a common name). Before this decade it had only been recorded four times until it was “rediscovered” in 2014 in Discovery Bay Coastal Park (south-western Victoria). The FNCV had an excursion to the area in December 2018, which included a successful search for the species there. Its common sibling species is Micraspis frenata (striped ladybird), to which Micraspis flavovittata is most similar to in appearance and size.

Several Micraspis species feed predominantly on pollen so are often found on flowers. Initial modern observations of Micraspis flavovittata were on and around large water-ribbons (Cycnogeton sp.) that were in flower and producing large quantities of pollen, so it was assumed the beetles at least supplemented their diets this way. These aquatic plants are quite common and widespread but despite my extensive searching of these plants throughout the state I could find no more beetles.

I had been keeping all my photos since acquiring my first digital camera in 2001 (except those that I lost through poor backup procedures). [There’s no reason not to keep all your photos as a 2TB drive costs around $100 and could store a lifetime’s worth.] In the last five years or so I had been recording my sightings on BowerBird and ALA (and more recently here on inaturalist.org). When I had spare time (usually in winter) I would go through my old images and submit them as well (if I knew reasonably accurately where they were taken).

A few months ago I was looking for a record of mine on ALA but thought it had been lost until I realized I was only half way through processing my older photos from 2011, so I started processing a few more. When I got up to mid December I found an image of a lady beetle from the Otways that, although at the time I had no idea of what it was, I can now recognize well. It was of course Micraspis flavovittata rediscovered three years earlier – “prediscovered” if you like. At the time I had nowhere to put an average quality photo of an unidentified beetle so it just sat there for seven years. Incidentally after the 2014 discovery was publicized a Warrnambool resident had mentioned they saw a similar beetle a few years earlier that nobody could identify – but they didn’t keep their photo!

This Otways site is in Aire River Wildlife Reserve beside the Great Ocean Road in Glenaire. It consists of a drained floodplain or swamp now extensively covered predominately by exotic herb species (weeds). With a variety of flowers it would appear to provide a pollen food source for long periods throughout the year and the dense coverage also provides protection from weather or other threats. Along with the swamp areas in Discovery Bay Coastal Park, this site indicates that Micraspis flavovittata favours damp to wet areas and perhaps does not tolerate dry areas and open forests. Although the the two historical sites east of Melbourne have seen significant clearing, development and agriculture there should still be places the beetle has survived too so it is still worth searching. One site in Buxton that was explored in late 2014 as a potential beetle site turned out to be the only regular location now east of Melbourne for the endangered Ancient Greenling damselfly (Hemiphlebia mirabilis).

Also at Aire River two common lady beetle species were observed: Harmonia conformis and Coccinella transversalis.

Insects need thickly vegetated areas in which to roost, shelter and hibernate, habitat often missing in our cultivated farmlands and urban areas.

Links:
2011 observation
2019 observations
earlier post about this beetle

Publicado el marzo 26, 2019 09:27 MAÑANA por reiner reiner | 1 comentario | Deja un comentario