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It is lady beetle season here. There are dozens of the larvae in our garden, so we collected some up and have been watching them, and feeding them aphids and mealy bugs. The larvae moult several times, getting larger each time.
Lady beetle larvae
We weren’t sure what species they would be. We didn’t find any kind of overview with information about the species that are in NZ, which are both native and introduced. It is especially difficult to find information about the larval stage.
After a couple of days, the first few larvae started to pupate. The pupa was a yellowy colour, later becoming much darker – almost black.
Pupating larvae on left, larvae on right
One evening, about a week later, the first beetle hatched. At this stage it was a pale cream colour.
Emerging from the pupa stage
Pupa after a beetle has emerged
By the morning it had turned the classic red and had two black spots. So probably, we have Adalia punctata. We now have about 8 beetles, apparently all of the same species.
We have since found a little more information, including this paper here. There is also information on the Coccinellidae family on Wikipedia.
The beetles don’t seem to be quite so keen on the mealy bugs, but are enthusiastic about the aphids.
Ladybeetle and aphids, on a rose bud
And we now have several bright orange clusters of lady beetle eggs. Quite a few clusters of eggs were laid, but also quite a few of those were eaten by the beetles themselves. Lady beetles are described as ‘voracious’ feeders, with some eating 1000 aphids in a life time.
Cluster of lady beetle eggs
The whole life cycle was quite quick and we can recommend these as a species to try, if you would like to keep some insect pets.
Life cycle of the 2-spotted lady beetle. A, the adult beetle.
B, group of eggs on under surface of a leaf.
C, a young larval beetle covered with white wax.
D, the full-grown larva.
E, the pupa attached to a leaf by the discarded larval skin
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We found some backswimmers in a water lily pond and bought them home to study. These bugs have an elongated pair of back legs for propulsion and swim on their backs (unlike water boatmen). They are predators, eating other pond invertebrates, including mosquito and other larvae.
They trap an air supply on hairs on their back. You can see the shiny bubble of air in the photo below.
The male animals stridulate, to attract a mate. This chirping sound is made by rubbing a rough area on their legs against their head. In spite of being underwater the sound is quite loud. When it’s quiet at night, you can hear them throughout the house. Here’s a recording of a couple of chirps.
This is the waveform. There are two short chirps three-quarters of a second apart, followed by a string of closely spaced chirps. Typically there are five chirps, but we have observed up to a six and as few as two chirps in the sequence.
Zooming in on a single chirp, it’s a 5kHz tone with an 800Hz modulation.
- Silver Y caterpillar – also known as a looper caterpillar. The head is on the right in this photograph.
The youngest member of the Chaos team spotted a new type of caterpillar on a Sunflower plant. To find out what it was, he kept the caterpillar in one of our terraria, and supplied it with fresh Sunflower leaves.
The caterpillar was similar in colour to the cabbage white butterflies we also had, but a different overall pattern, shape and size. They move in the classic ‘inch worm’ style, due to having only two pairs of legs at their abdomen. Eventually it spun a relatively open cocoon,
Pupa, after the silver Y moth had emerged
This was the ornate moth that emerged several weeks later.
Silver Y moth
Silver Y moth (Chrysodeixis erisoma) is our best guess at identifying this species – identifying a moth can be challenging. There are a number of books available on New Zealand species, although none cover all of the species. Identification is further complicated by many of the images in books, and online, being of dead individuals that have their wings outspread. These can look very different, as in this.
Landcare Research provide an extensive image gallery online here.
The silver Y moth, prior to its’ release.
Our next goal is to find a cabbage tree moth or caterpillar – these chaps have stripes on their wings that match dead cabbage tree leaves, and apparently orient themselves on the leaves so that these line up – how cool is that?
