Parischnogaster nigricans serrei is a hover wasp subspecies in the family Vespidae, and it is predominantly found in the Java region of Indonesia.

Studies investigating the biology and social behavior of subfamily Stenogastrinae wasps have begun since the early 20th century, but some of their unusual morphological and ethological traits make it hard for them to have a specific systematic allocation in the phylogenetic tree.

[1] Therefore, studying subfamily Stenogastrinae species has long been regarded as a way to investigate the evolution of social life in Hymenoptera due to the wide spectrum of eusociality displayed in their wasps.

Additionally, male wasps have three white stripes on their tergites, which is associated with patrolling and mating behavior, but females do not display such morphological features.

Some nests have been found to be attached onto plant stems, lichens, veins of dead leaves, roots, or even iron threads, cords, and electric wires.

[2] Parischnogaster nigricans serrei has been identified in the village of Tegallega, near Bogor, and in the western part of the Java Island of Indonesia.

[2] This kind of habitat choice is rather unique of P. nigricans serrei (along with Parischnogaster mellyi), since Stenogastrinae species are rarely populated in areas disturbed by human contact and civilization.

[2] Patrolling activity is one of the characteristic behavioral features of P. nigricans serrei, and similar to P. mellyi; displaying their abdominal white stripes while hovering is frequently observed.

A typical contest usually involves a tandem flight where the two males ascend, suddenly changing position (the owner goes behind and vice versa), displaying their abdominal stripes, and eventually clashing until one of them surrenders and leaves the landmark.

Ant guard development begins around the first couple days, after the construction of the first cell, and it is typically built from material excreted from the tip of a female gaster.

However, in the case of P. nigricans serrei, females can vary in terms of the timing of fertilization and the onset of ovarian development.

The trend of females with large ovaries mating sooner could be how sterile workers evolved when the period of virginity endured indefinitely.

Additionally, dominant females devote most of their time to resting in their nest, but often showed patrolling and inspecting behaviors in the morning.

[3][10] Parischnogaster nigricans serrei exhibit similar egg deposition behaviors as other Parishnogaster species such as P. alternata.

Abdominal secretion from the Dufour’s gland is characterized by egg-sized white, jelly-like droplets, and it has been observed to play an important role during oviposition (attaching the egg to the bottom of the cell).

The wasp collects this gelatinous material while placing its posterior and middle legs on the nest with its gaster bent towards the mouth.

Egg laying in the Stenogastrinae hover wasps is quite unique, and it consists of three distinct phases: In the first stage, as discussed before, the female ventrally bends her gaster towards the mouth and collects the abdominal secretion.

[3] A number of Stenogastrinae species have shown foraging behaviors through plucking small arthropod preys off of spider webs; this holds true for P. nigricans serrei as well.

In captivity, P. nigricans serrei have been reported to have easily plucked off small crickets or flies (typically Drosophilae), which were attached to the windows of a cage with drops of honey when they were captured.

[2] It has been observed that the Greater Banded Hornet, Vespa tropica, often preys on colonies of P. nigricans serrei by destroying cells to remove fully grown larvae and pupae.

Adult P. nigricans serrei do not show resistance to such attacks and often abandon the colony, returning when the raid ceases.

Additionally, nests with high larval and pupal populations exhibit a higher rate of consecutive attacks by the hornets.