#58 Christmas beetles get busy

Christmas Beetles are busy passing on their genes at this time of the year, and I am particularly pleased with the series of images I captured of one species in action.

Over two days in mid December, I found Black Nail Beetles (Repsimus manicatus) in numbers on a couple of my Callistemon shrubs. With a ladder, and a good dose of patience and a healthy sense of discovery and humour, I searched for mating pairs, and was rewarded with good views of the entire act.

Black Nail Beetles (Repsimus manicatus) are so called

because the elytra (wing covers) resemble long black

polished fingernails

Adult beetles emerge during the early to mid summer period from the soil, hence the common name of "Christmas Beetles". From Family Scarabaeidae, there are approximately 34 species of Christmas Beetles distributed throughout Australia, most commonly in the high-rainfall coastal areas of eastern states.

Life Cycle of the Christmas Beetle

The life cycle extends over one or two years, depending on species. Eggs are laid into soil or compost in the spring and early summer. Females are capable of laying between 20 and 40 eggs each. Newly hatched larvae feed on organic matter in the soil, and older larvae feed on organic matter and/or roots. Ref: Dept Primary Industries, Queensland.

The larvae have a distinctive 'C' shape and are often called curl grubs. In late winter/early spring fully-grown larvae move close to the surface and hollow out a chamber in which they pupate. Pupation lasts several weeks.

After pupation the new adults must wait in the soil for suitable conditions, usually when the soil is softened by rain, allowing them to dig their way to the surface. In very dry conditions the beetles cannot burrow to the surface, and die in the soil. In flooded conditions they will drown. Ref: Dept Primary Industries, Qld.

The underside of a Black Nail Christmas Beetle as it eats

After emerging, beetles fly a short distance to food plants to feed and mate. The females then return to the soil and lay eggs, although some lay eggs before feeding. Feeding and egg-laying may continue for several days. Adults may live for some weeks. Ref: Dept Primary Industries, Qld.

Adults are voracious feeders and large swarms can rapidly defoliate trees. Although the damage to my Bottlebrush shrubs is evident, it is not extreme, and a light prune will be all that is needed to tidy them up.

Black Nail Beetles ( Repsimus manicatus) copulating.

- notice the distinctive difference in size and

shape of the hind legs of male and female.

The Black Nail Beetle has immensely developed hind legs, with the male having thicker legs than the female. When I disturbed the beetles, they raised back legs in a horizontal posture, presumably to assume a more threatening size as a defense strategy.

It was interesting to note that the Black Nail Christmas Beetles were not attracted to the porch light of a night.

The large hooked back claws are not used in mating,

but for moving about the foliage

This image shows a thick white fluid oozing from

the female's reproductive canal

. . . . . and this image illustrates the shape of the male's

reproductive organ just withdrawn from the female

It might sound like a rather odd pastime, spying on the mating practices of beetles, but what fascinating up-close observations! And all in my garden! This is the first time I have noticed this species of beetle in my yard, so it was a beaut find.

***** ***** *****

Christmas is different things to different people. I hope everyone stays safe over the festive season, and has reason to smile. I'd like to send a special "cheerio" to those who might be lonely, alone, unwell, low in spirit, or down on luck.

Seasons greetings from Gaye from the Hunter

#56 Backyard predators

When we refer to predators in Australia, creatures like raptors, dingoes, foxes and feral cats are first to come to mind, but we will all have predators of a less conspicuous nature in our immediate outdoor living space - birds, lizards, snakes, frogs, spiders and other invertebrates.

Magpies are amongst the most endearing predators to regularly visit my backyard. The Australian Magpie (Gymnorhina tibicen) has several races. It is my understanding, (I am happy to be corrected here), that there are 8 variable races in Australia in two major groups (black-backed and white-backed), with wide hybrid zones between them.

As far as I am aware, the only Magpie in the Hunter Valley is the black-backed G tibicen (race terraereginae). With its delightful chortle and playful nature, the magpie is a very welcome visitor to my yard. Not only are they entertaining, but they also play an important role in keeping the invertebrate population under control. With keen hearing, they are excellent predators.

Our backyard Magpie collects grubs

and Wolf Spider for its young in the nest

Other common feathered predators to visit my backyard are Masked Lapwings, Willie Wagtails, Silver-eyes.

During the warmer weather, my backyard is home to many species of spiders. Most are web-builders who wait for their meals to come to them, but there are some predators amongst my local spiders. Most obvious is the Garden Wolf Spider (Lycosa godeffroyi).

Up close, Wolfies can be a scary sight, but they are relatively harmless unless provoked. At night, and on grey days, these fearless hunters can be spotted moving about their environment looking for a meal. I have seen them catch spiders, beetles, and various unidentified invertebrates. They are an awesome predator!

A Garden Wolf Spider tackles a large beetle

I have had the opportunity to watch a few species of lizard hunt in my backyard. Having an Eastern Water Dragon (Physignathus lesueurii) choose to live in my garden for nearly two years, I was privileged to observe his life in detail.

Bearded Dragons (Pogona barbata) and Southern Rainbow Skinks (Carlia tetradactyla) have also spent time living in my backyard. All three lizard species have different hunting techniques.

A Water Dragon catches more than he can handle.

The lizard was not able to dismember the frog,

and can not eat it whole.

Although I have photographed and identified nine species of frogs in my backyard, I have unfortunately not seen a frog actually in the act of catching its prey.

Wasps are efficient predators. Mud Dauber Wasps (Sceliphron laetum) and Potter Wasps (Eumenes latreilli) breed in my backyard most summers. Although they feed on nectar, they prey on spiders and caterpillars to stock their breeding chambers for their developing young.

A Potter Wasp stuffs a caterpillar into a breeding cell

Some ants prey on living creatures. I have observed Green-head Ants (Rhytidoponera metallica) preying on living caterpillars in my garden, but the following picture of one of the "Inch Ants" carting off a live bee was taken in coastal sandy heath in the lower Hunter Valley.

An ant carts off a live, pollen-laden bee

Although I have not observed snakes hunting in my immediate vicinity, I was very fortunate to witness the following scene where a Stephen's Banded Snake (Hoplocephalus stephensii) had just killed a large Peron's Tree Frog (Litoria peronii) in the rainforest of Barrington Tops National Park in the east of the Hunter Valley.

Snake catches frog

So, lurking in your backyard, there could be a variety of predators acting out spectacular hunting and killing scenes. Predators will even prey on predators. The secret lives of our backyard native creatures are fascinating.