Classification: | Phylum: Arthropoda | Class: Insecta | Order: Hemiptera | Family: Scutelleridae | Genus: Cantao |

The other common names of this bug are Jewel Bug or Shield-backed Bug. In Singapore, the Mallotus Shield Bug is found breeding exclusively on the Mallotus paniculatus (Turn-in-the-wind). A number of host plants have been reported in other countries. In India, it was first reported on the Macaranga peltata (synonym: Macaranga roxburghii) [1] and Kigelia pinnata (Sausage Tree) [2]. In Japan, the host plant is Mallotus japonicus (Japanese Mallotus Tree) [3].

This bug usually lays a large number of eggs on the underside of the host plant and then sits over them until they are hatched. Based on my field observations so far, it is very determined to guard its eggs and will not move away from them even when the surrounding leaves were disturbed. The life history [2] and parental care phenomenon [4] of this bug has already been well documented back in the 1920s.

A report on this bug in Singapore was published in 2012 [5].

Reference articles:

1. Distant, W. L. 1902. Fauna of British India. Rynchota. Volume 1. London: Taylor and Francis. pp. 43.

2. Ayyar, T. V. R. 1920. Notes on the life-history of Cantao ocellatus, Th. Report of the Proceedings of the Third Entomological Meeting Held at Pusa on the 3rd to 15th February 1919. Vol. III.. Superintendent Government Printing, Calcutta, India. pp. 910-914.

3. Kaiwa, N., T. Hosokawa, Y. Kikuchi, N. Nikoh, X.Y. Meng, N. Kimura, M. Ito, T. Fukatsu. 2010. Primary gut symbiont and secondary, Sodalis-allied symbiont of the Scutellerid stinkbug Cantao ocellatus. Appl Environ Microbiol. 76 (11): 3486-3494.

4. Takahashi, R. 1921. Parental care of Cantao ocellatus Thunbg. Transactions of the Natural History Society of Formosa 11: 81-86.

5. Leong, T. M. & B. P. Y-H. Lee, 2012. Records and natural history of the ocellated shield bug, Cantao ocellatus (Thunberg) in Singapore, with observations on egg guarding, hatching, parasitoids, moulting, feeding, and mating (Hemiptera: scutelleridae: scutellerinae). Nature in Singapore, 5: 249-262. | Read article |

In November 2015, I came across many of the nymphs crawling on the concrete floor and some on the pillars of the apartment block where I stayed. A number of them were on their back and motionless, presumably dead. Shortly, I traced the unusual appearance of the nymphs to a few fruiting Mallotus paniculatus trees on the edge of a park about 100 metres away from the apartment block. It was uncertain why some of the nymphs decided to leave the trees and move a long distance down a slope to a much dangerous place.