A new species of bee-mimicking clearwing moth (Lepidoptera: Sesiidae) from Thailand, with description and video of its behaviour

Highlights

• A new species of bee-mimicking clearwing moth from Thailand is described.

• Video of its flight and mud-puddling behaviour is provided.

• This is the first record of the genus Aschistophleps for Thailand.

• Its astounding mimicry includes morphology, behaviour and acoustics

Abstract

Unique footage of flight and mud-puddling behaviour of a new species of clearwing moth (Lepidoptera: Sesiidae) was filmed in its habitat in Thailand. Aschistophleps argentifasciata, morphologically resembling a bee, imitates its model also in the way it flies. This behavioural mimicry, as well as mud-puddling, filmed both in real-time and slow motion (500/1000 frames per second), are shown in a supplementary video and described herein. A morphological description of the new species, including male genitalia, mimicry features, differential diagnosis from closely related species and information on the habitat, time and conditions of occurrence are provided. This is the first video of the genus Aschistophleps ever published and this species is the first country record of Aschistophleps for Thailand.

Introduction

Members of the family Sesiidae are a classic example of Batesian mimicry (Robinson et al., 1994). A new species of bee-mimicking clearwing moth, Aschistophleps argentifasciata (Fig. 1, Fig. 2, Fig. 3, Fig. 4), has been discovered in Thailand, being also the first record of the genus in this country. The genus Aschistophleps is characterised by the presence of two tufts of hair-like scales on the hind legs and elongated scales on fore and mid legs (Hampson, 1892), which together give it a “hairy” bee-like appearance. It has been recently observed that morphological mimicry in clearwing moths can be complemented by behavioural aspects, such as imitating the flight trajectory of bees and wasps (Skowron et al., 2015, Skowron Volponi and Volponi, 2017a) or sounds made by the mimicry models (Skowron Volponi and Volponi, 2017b). A. argentifasciata was observed and filmed flying in a bee-like manner in its natural habitat whilst mud-puddling (Supplementary Video 1). Many different hymenopterans were seen in the same area, including similar sized and shaped bees. The new species was seen several days in a row in the same area, but always only one or two individuals were present. This indicates that they do not occur in large numbers, in contrast to numerous bees flying in that location. In Batesian mimicry, being rare in comparison with the model(s) is advantageous for the mimic, because it increases the chances of not being disguised by the predator (Matthews and Matthews, 2010). This publication includes a description of mud-puddling and mimicry behaviour and a detailed video showing this sesiid in its natural habitat (where the species occurs without being lured by sex pheromones), a morphological description, mimicry features, differential diagnosis from closely related species, habitat, time and conditions of occurrence.