BUGS FOR THE AMATEUR
June 2005; Sai Kung Country Park.
The nests of this species are founded by a single inseminated queen (independant founding). She will select a site and construct the 1st brood cells. However, when she is out foraging to feed the 1st young larvae, she leaves the nest un-attended and the brood may fall prey to ants particularly. Consequently most independent founding Polistes apply to the nest petiole a secretion from a gland (van der Vechtís gland) situated on the sixth gastral sternum that acts as an ant repellant. However, this mechanism is not confirmed for P. japonicus.
Polistes japonicus is easily confused with P. olivaceus. Ground color and general morphology are rather similar, only inspection of the thoracic details (carinas, punctuation etc) permits a positive identification.
|Polistinae: Polistini: Polistes japonicus de Saussure, 1858, sub-genus Polistella
March 2007, Sai Kung Country Park. A young queen on a newly initiated nest, 4 days after the site was chosen.
May 2006, Sai Kung Country Park. A young queen on a nest still at initiation stage, with the 1st pupae visible. Note the yellow cocoon caps typical of this species.
May 2006, Sai Kung Country Park. A view of the same nest showing the brood content.
July 2006, Tai Po Kau Forest Reserve. A mature nest.