Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Scale shape and colour of egg batches of some Thaumetopoea species (Insecta Lepidoptera Thaumetopoeidae).

Abstract

The egg batches of 5 different species of Thaumetopoea were collected from the needles and twigs of pine trees (Pinus spp.), the bark of oak trees (Quercus robur) or the twigs of cedar trees (Cedrus atlantica) in 1988-90 at 12 sites in 7 countries in Europe and North Africa (Germany, Algeria, Israel, Bulgaria, Greece, Morocco and USSR (RSFSR in Europe)). The morphology of the egg batches and the colour and shape of the scales were compared to investigate the possibility of differentiating the species. The egg scales of T. processionea were very small and pointed and least similar to those of the other species. The scales of T. pinivora and T. bonjeani were similar in size and shape, but the egg batches differed in colour and structure. The scales of T. wilkinsoni and T. pityocampa were larger and wider than those of the other species. Those of T. wilkinsoni were round in shape, and although of a similar width to those of T. pityocampa, were shorter. In general, the scales from the base, and in most cases, the scales from the top of the egg batches were smaller than those from the middle. It is therefore suggested that scales from the middle of the egg batch are used for the purpose of species identification.