Annual Cattana Wetlands Night Walk

 The 2024 Cattana wetlands Nightwalk was held on 28 September. It was a perfect night, warm and dry,

We counted 123 eager participants. Many had returned from previous years but there were other "newies" who had seldom ventured out in the dark to see what was happening in their gardens.

We divided into 4 groups and took off in various directions. Some did not go far and saw a variety of insects, spiders, frogs and lizards within the vicinity of the light sheets. Others were more adventurous and took off to find a crocodile---they were rewarded, fortunately the crocs were under a metre in length!

Lights were set up under the picnic area for folks who did not want to travel far and a variety of moths and other insects delighted them.

A highlight at the light sheet was the day-flying moth, Dysphania numana. It was probably spending the night nearby and was confused by the strong lights. 

Night time is great for orthopteroid insects. They are easily seen as they venture out for food and mates and are approachable with a camera. This is a nymph of an agraeciine conocephaline (quite a mouthful!) that is about half grown. It will eventually be fully winged when it becomes an adult.

This is a Raspy Cricket (family Gryllacrididae), probably the genus Nunkeria. The long ovipositor tells us it is a female and that it lays its eggs in the ground. Raspy Crickets are so called because they can produce a sound by rubbing the insides of their hind legs against a series of minute pegs on the adjacent side of the abdomen. This results in a characterisitc rasping sound. These crickets can also produce "silk" from secretions from their moutnparts. The silk comes out in strands and is used by some species to tie leaves together to form a shelter where they spend the daylight hours or in other species to reinforce the sides of their burrows in the ground. Some of these species use the silk to build a cap to the burrow by holding sand grains in place. This is similar to the situation with Trap-door Spiders.

Spiders are always a hit with the night walk crowds, especially the children. This orb-weaver, probably Tetragnatha sp, is a male judging by the expanded chelicerae. It was in the middle of "web management" when we stumbled by.

But the entomological night went to the Cockroaches with one new species and one undescribed genus discovered.

Cockroaches are photogenic at night. If you are careful, they will continue their activities and not scurry away as they would during the day. This one is a member of the subfamily Blattellinae.

This is a fairly common, plain cockroach across the far north tropics. It is called the Pandanus Cockroach, Megamareta phaneropyga. It is nocturnal and not exclusively associated with Pandanus, although they are not usually found very far from that plant. It would never survive your home.

Most cockroaches are nocturnal. They venture forth at night from their shelters in unfurling leaves or from protection in leaf litter. They forage on leaf surfaces for pollen, floral parts and any other "digestible" food. They frequently feed on undigested bits in bird droppings. This is an undescribed species in the genus Carbrunneria.

The patterns on the thorax are ussually species distinctive in colour and design in many cockroaches and have beeen used in identification.

We will probably have another Night Tour at Cattana early in the new year, weather permitting.