Plain Grey Hawkmoth (Psilogramma increta) – Wildlife of Japan

Introduction

The Plain Grey Hawkmoth is a large hawkmoth species recorded widely in Japan.
It is known for its subdued gray appearance rather than bold markings or bright colors.

In Japan, this species is called Shimo-furi-suzume.

Appearance

Adults have long, narrow forewings and an overall gray to gray-brown coloration.
Fine, dark lines run across the wings, creating a simple and understated pattern.

The wingspan is generally reported to be about 9–12 cm, placing it among the larger hawkmoths found in Japan.

Habitat & Distribution

In Japan, this species has confirmed records from Hokkaido, Honshu, Shikoku, Kyushu, and many southern islands.

It is mainly associated with forested areas and forest edges, but may also appear near human settlements depending on local conditions.

Behavior

The Plain Grey Hawkmoth is nocturnal.
Most records are based on nighttime observations, and detailed behavioral information is limited.

Diet

Larvae are known to feed on a variety of plants across the species’ range, indicating a non-specialized feeding habit.
Specific host plant details for Japan are not consistently documented.

Reproduction

Like other hawkmoths, this species undergoes complete metamorphosis: egg, larva, pupa, and adult.
Further details such as the number of generations per year vary by region and are not well documented for Japan.

Conservation

This species is widely distributed and is not generally regarded as threatened.
No specific conservation concerns are commonly noted in Japan.

Author’s Impression

At first glance, the Plain Grey Hawkmoth appears simple, but its smooth gray tones and streamlined shape give it a quiet, solid presence.
It feels like a species built for night flight rather than visual display.