Published via Ecency

Latin Name	Observation Date	Location
*Evaniidae*	Jun 04, 2026	Purulia, Natore, Bangladesh

Name:
Among the many different insects found in nature, the Ensign Wasp is one of the most interesting insects. It is best known to the general public as the Ensign Wasp. However, based on its physical structure and behavior, it is also called the nightshade wasp, hatchet wasp, and cockroach egg parasitoid wasp. While walking, they move their abdomen up and down like a flag, which is why they have been given such a unique name.

Scientific name:
Since this is not a specific insect, but a whole family of parasitic wasps, they do not have a single scientific name. However, the scientific names of the two most well-known species spread around the world under this family are Evania appendigaster and Prosevania fuscipes.
Family and Genus:
This insect, which belongs to the Insecta class of the large Arthropoda phylum, is a member of the Hymenoptera order. Their superfamily is Evanioidea and they belong to the Evaniidae family. There are about 20 living genera and more than 400 species in the world today. Among them, the genera Evania, Evaniella and Zeuxevania are notable. Before 1939, any strange-looking parasitic wasp wasp was considered to be part of this family.

Size and body structure:
The body structure of these wasps is quite strange and completely different from other common insects. Their size is not very large, usually around 5 to 7 millimeters. Their metasoma or abdominal part is very small and is attached much above the hind legs. The abdomen has a long tube-like part called a petiole. Their head is very tightly connected to the chest, which cannot move much. Both male and female cockroaches have long antennae divided into 13 segments on their heads. The female wasps egg-laying organ or ovipositor is quite small and thin.

Habitat and habitat:
This species of wasps has survived on earth since ancient times. Fossil records show that they existed about 150 million years ago, that is, during the time of dinosaurs. Surprisingly, their physical structure has not changed much after all these years. Nowadays, they can be found on almost all continents except the extremely cold regions of the world or the polar regions. Since cockroaches are more common in human homes, these cockroaches are also often seen roaming around human habitations in search of prey.

Food:
The diet of adult wasps and their larvae is completely different. Adult Ensign wasps do not spoil any human food or hunt other animals. They mainly live by drinking honey or nectar from various flowers. On the other hand, their larvae are completely carnivorous and parasitic in nature. They survive and grow by eating only cockroach eggs.

Reproduction:
Their reproduction process is one of the wonders of nature, which is completely cockroach-dependent. The female Ensign wasp roams around in search of prey and finds the cockroach egg sac or ootheca. Then she uses her delicate ovipositor to lay her eggs inside that sac. When the egg hatches, the wasp larvae quickly emerge and start eating the cockroach eggs inside. The larvae develop into full-fledged insects inside the egg sac. If somehow more than one egg is laid in the same sac, the larva that hatches first will also eat the eggs of the other wasp.

Benefits:
Ensign wasps are a very beneficial insect for our environment and humans. Since they eat and destroy cockroach eggs, they play a great role in naturally preventing the spread of cockroaches. The most important thing is that they do not sting or bite people like ordinary wasps. Their larvae or adult insects are not harmful to humans at all.

Harmfulness:
They do not have any direct harm to humans or the environment. However, one of their major limitations is that they cannot reproduce very quickly or in large numbers. So although they help control cockroaches naturally, they cannot be completely relied on for commercial or large-scale cockroach control.

Hope you like it.

I learned about them from various sites including iNaturalist, Wikipedia and Google.

(All posts are written in Bengali and translated into English using Google Translate.)
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Camera Used	Samsung SM-G973F
F-Stop	F2.4
ISO speed	ISO
Focal length	26mm
Flash	No
Editing app	MIX
Photography	(Ensign Wasps, Evaniidae)
Photographer	@mshbd
Location	Purulia, Natore, Bangladesh