Malayan horned frogs are about 12 cm long, with females being much larger than males. The frogs are characterized by their large angular head, with projections over their eyes and nose. This, along with their grey-brown colouring, makes the frog look like dead leaves on the forest floor. When the frog sits still on the forest floor, it’s pretty much invisible.
That’s how Malayan frogs hunt; they sit there, still as a statue, until some poor creature wanders by. The frogs then jump onto the prey and engulf it. These frogs will eat pretty much anything they can catch, but seem to eat a lot of scorpions and crabs, which form the bulk of their diet. Other items of food include arachnids, young rodents, lizards and other frogs.
How males and females breed in the wild is largely unknown, but once mated, the females lay their eggs on the underside of rocks and logs that touch water. Eggs that touch the surface of the water hatch into tadpoles and start their life’s adventure. Those eggs that are too high above the water slide to the water on thin threads of egg covering. The tadpoles themselves are even weirder; they have a large funnel-like mouth, which they use to cling to the waters surface. They do this because they feed on microbes at the surface, but it’s got to look really strange.
The Lygaeid, Phaenacantha (Colobathristes) saccharicida, Karsch, all stages of which are described, has long been known as an occasional pest of sugar-cane in Java, but since 1926 it has been present in the cane fields in the west of the Island and has been multiplying enormously. The eggs hatch in 8-14 days, and the adult stage is reached 29-34 days later, after which the bugs may live at least 6 1/2 months. The eggs are laid in damp sheltered places on the ground, on the cane leaves or inside the leaf sheaths. Females laid an average of one a day during the 2 1/2 months they were observed; in the dry season (May to August) very few eggs are laid, so that not more than 4-5 generations occur annually. Both nymphs and adults usually feed on the lower surface of the leaves; yellowing of the leaves and stunting of the cane result from the attack, and this probably delays ripening. After the old cane is cut, the bugs migrate to new fields. On hot and especially on windy days they seek shelter in cracks in the ground or between lumps of earth at the base of the cane stool. When such places are not available, as in newly planted fields, they migrate to neighbouring weeds, leaving them at night to feed on the cane.
Fowls feed readily on the bugs. An unidentified parasite, probably an Encyrtid, was reared from the eggs and has also been found by Van der Goot in the eggs of Leptocorisa acuta, Thnb., and Nezara viridula, L. Details of its morphology and biology are given. It multiplies more rapidly than P. saccharicida, but is handicapped by the migration of the latter to new fields and by the scarcity of its eggs in the dry season. As a result of experiments, the following combination of measures is recommended. Leaves should be burnt immediately after harvesting. Weeds near the fields should be burnt or treated with a spray of tobacco and soap or calcium cyanide dust. These insecticides may also be used on young cane and against bugs hiding on the ground. The bugs may also be caught with nets, or torches may be used at night, the bugs flying into the flame when the plants are shaken. Heaps of cane leaves may be used as traps.