The Chequered LancerPlastingia naga and the Yellow Chequered LancerPlastingia pellonia are the only two Plastingia species in Singapore. Both are forest species and like to rest in the shade of the undergrowth with folded wings. The only time they open their wings is to bask in the sunshine when puddling. The former is uncommon and the latter is rarer.
I have yet to see the Yellow Chequered Lancer but have encountered the Chequered Lancer on two occasions at Dairy Farm Nature Park and Upper Seletar Reservoir Park. Unfortunately they were too quick for me to get any photographs.
Over the year, there were several sightings of the Chequered Lancer along the forest trails at MacRitchie Reservoir, which I missed. So it was third time lucky when I came upon a tame individual resting by the side of the trail on 1st Sept 2022.
What made this encounter special was getting photos of the top view and the side views of their full wing spread. I cannot find any photos of the Yellow Chequered Lancer upper wings but I read that both look similar with the white spots of the Yellow Chequered Lancer appearing larger than the Chequered Lancer. Whereas the underside is very different. The markings of the Yellow Chequered Lancer are yellow while the Chequered Lancer markings are white, giving it a black and white chequered look.
The grass and reed beds by the sides of our inland reservoirs is a micro ecosystem by itself. It is teeming with insect life, mainly dragonflies, damselflies, grasshopper and some butterflies. I have been visiting the wetlands around our freshwater reservoirs mainly to photograph the odonatas.
Fong and his brother were photographing what looked like a Saint Andrew’s Cross SpiderArgiope versicolor, wrapping up a motionless Common Scarlet dragonfly that got caught in its web.
All my past sightings of the St. Andrew’s Cross Spiders were by the forest edges and along the jungle trails in our nature reserves. This is the first time I seen it with its web across the long grasses by the water edge. How and why did this spider move out of the forest to a very different habitat was a puzzle to me. Could it be that there is a lack of insects or looking at a change of diet?
I did some checking in Biodiversity of Singapore and found that this is the Yellow-Silver St. Andrew’s Cross Spider, Argiope cantenulata, ( Marcus Ng), also known as a Grass Cross Spider. This orb-weaver spider is found from India to the Philippines and Papua New Guinea.
It preys mainly on dragonflies that hunt and breed in this habitat. Once it flew into its web, the spider quickly immobilizes it by spinning and wrapping the prey with its web. It then injects digestive enzymes into the victim to break down its body tissues. The spider sucks up the pre-digested tissues and repeats the process again. It seems to be locally common with most of the sightings along the edges of reservoirs. Apparently they are quite common in the padi fields in Malaysia.