Spilosoma hypogopa Hampson

Diacrisia hypogopa Hampson, 1907, Ann. Mag. nat. Hist. (7), 19: 235.

Spilosoma hypogopa Hampson; Holloway, 1976: 4.

Diagnosis

The species can be distinguished from other yellow Bornean taxa by the dorsal black streak on the thorax in combination with cream-coloured antennae and the extensive dark markings on the forewing dorsum.

Taxonomic notes

A series of specimens with much reduced black markings and a stronger roseate suffusion, particularly in the female, on the forewing underside are here considered to be a variant of hypogopa as there are no appreciable differences in the male genitalia. Males of both forms are illustrated. The lightly marked form is perhaps more frequent in open and disturbed habitats.

Leong & Chang (2010) described and illustrated the larvae of *S. *hypogopa in Singapore, feeding on the bird’s nest fern, Asplenium nidus (Aspleniaceae), individually or in groups. The larvae were typical of the genus, densely invested with plumose secondary setae arising from low verrucae. These and the body were black at the anterior and posterior ends, with an orange‑brown central section. The larvae dispersed to pupate. Those retained formed dense ovate cocoons incorporating larval setae woven together.

Though this one observation cannot be taken as indicative of specialism, it is interesting to note that the only host record for the related Sundanian species *S. *vandepolli is from Angiopteris (Marattiaceae), another fern (Robinson et al., 2001). Cerný (2011) has recorded both species from the Philippines, hypogopa from Palawan and vandepolli from Mindanao and Negros. The record of hypogopa from Thailand (Cerný & Pinratana, 2009) is probably of a distinct species (K. Cerný, pers. comm.).

Geographical range

Peninsular Malaysia, Sumatra, Borneo.

Habitat preference

During the Mulu survey and in Brunei the species has been taken infrequently in lowland forest and secondary vegetation. The highest record is from 1200m on G. Kinabalu.

Taxonomic Note

Leong & Chang (2010) described and illustrated the larvae of S. hypogopa in Singapore, feeding on the bird’s nest fern, Asplenium nidus (Aspleniaceae), individually or in groups. The larvae were typical of the genus, densely invested with plumose secondary setae arising from low verrucae. These and the body were black at the anterior and posterior ends, with an orange‐brown central section. The larvae dispersed to pupate. Those retained formed dense ovate cocoons incorporating larval setae woven together. Though this one observation cannot be taken as indicative of specialism, it is interesting to note that the only host record for the related Sundanian species S. vandepolli is from Angiopteris (Marattiaceae), another fern (Robinson et al., 2001). Cerný (2011) has recorded both species from the Philippines, hypogopa from Palawan and vandepolli from Mindanao and Negros. The record of hypogopa from Thailand (Cerný & Pinratana, 2009) is probably of a distinct species (K. Cerný, pers. comm.).

Genitalia: