Classification: | Kingdom: Animalia | Phylum: Arthropoda | Class: Insecta | Order: Hymenoptera | Family: Crabronidae | Genus: Pison |

In September 2019, I found a handful of this wasp hovering around a small area of my potted plants along the balcony. Further investigation led me to some tunnel openings on the soil surface dug by the wasps. I even saw one crawling into the hole but it was moving too fast for any picture to be taken. Finally in July 2022, I managed to capture the image of a wasp digging in my pot. The yellow arrow in the picture below showed the location of the digging wasp.

There were 2 native Pison wasp indicated in the Biodiversity of Singapore website as of July 2022, namely Pison suspiciosus and Pison argentatum. According to a 2004 publication [1] from the Philippines, Pison argentatum does not construct nest in soil. In a 2021 publication [2] from India, the name Pison suspiciosus was indicated to be a synonym of Pison punctifrons and it is also not a ground digger wasp.

Reference:

[1] Starr CK. Nesting biology of the solitary wasp Pison argentatum (Hymenoptera: Sphecidae) in Borneo and the Philippines. J Kansas Entomol Soc 2004;77(4):565-572. | Read article |

[2] Bais RKS, Bais AS. A new distribution record of mason wasp Pison punctifrons Shuckard, 1838 (Hymenoptera: Sphecidae: Larrinae) from Noida, Uttar Pradesh, India. J Threatened Taxa 2021;13(5):18227-182. | Read article |