Genus Pison

Of tribe Trypoxylini, Tasmania officially has four Pison species (P. spinolae, P. rufipes, P. simulans, and P. westwoodii) and one species of Aulacophilinus (A. calligonosum). Pison is distinguished from Aulacophilinus by the mandibles being apically slender instead of apically broad.

Pison spinolae is entirely black, notably hairy, and much larger than the other species listed here at around 14mm (other species around 6-9mm) – this species is popularly known as the Mason Wasp, the females often found within domestic settings provisioning their mud nests with numerous garden spiders. P. rufipes has largely reddish legs. P. simulans also has reddish legs, though the femora are black, and further differs from P. rufipes by the presence of only two fore wing submarginal cells instead of three. P. westwoodii is entirly black, like P. spinolae, but is smaller (around 9mm) and lacks the long silver hairing on the head and thorax. Aulacophilinus calligonosum is similar to P. westwoodii though, in addition to the previously mentioned mandible differences between the two genera, differs from the latter wasp by being slightly smaller and fore wings with two submarginal cells instead of three.

Pison spinolae (Mason Wasp)

    

Pison westwoodii

     

Pison rufipes
 

Pending ID – Pison
#1. Pison sp. (male)
Late February 2016
Knocklofty Reserve, Hobart
   

#2. Pison sp.
Mid December 2016
Peter Murrell Reserve, Blackmans Bay

#3. Most likely a Pison species nest laden with paralysed spiders.  Larvae of varied ages can be seen in many cells.
Late February 2017
Images by Jarrod Midson, used with permission.
    

#4. Pison sp. egg
Late February 2017
Franklin
Photos AD
The ‘stunned’ spiders below fell from mud nests constructed under a back-door frame when the door was opened. The spiders were collected for the record. The wasp egg was irreparably damaged by the fall. (See the next sighting for more wasp activity under the same door-frame.)
 

#5.  Pison sp. egg/larva
Late February to late March 2017
Franklin
Photos AD
An intact egg, and the provisioned spiders, from a nest (re-)constructed under the same back-door frame as the sighting above was collected to rear. The larva hatched, feeding through most of the spiders, and appeared to reach the sixth, and last, larval stage (larval stage determined by the shape of the mandibles), but unfortunately did not survive this last stage. The last two photos shows the traumatic slug-like extrusion from the rear of the larva that appeared to kill it – this extrusion was discovered days after the event, and is not known if it was a parasite, though likely.