RESUMO
Melolonthinae are the largest subfamily of Scarabaeidae, considered as serious pests for their larvae attacking plant roots and tubers. The edaphic larvae are difficult to be identified because the study on larval taxonomy is far from satisfactory. In this study, multivoltine white grubs Melolontha incana (Motschulsky, 1853) were investigated using light and scanning electron microscopy, in order to provide more morphological characters for the pest identification. The white grubs are atypical for the epipharynx bearing 14 heli arranged in two rows; the mandible is furnished with a patch of minute granules; the maxilla is equipped with 18 acute stridulatory teeth arranged in line; each femur and tibiotarsus is furnished ventrally with a cluster of fossorial setae. The morphological comparisons with the other melolonthine species were provided. The adaptative relationship between the morphological feature and the multivoltine life history were briefly discussed.
Assuntos
Besouros , Animais , LarvaRESUMO
Lucanidae have long received great attention for their adults. However, differentiating between the larvae of stag beetles is difficult and remains unsatisfactorily resolved due to the microscopic features separating groups. In the current study, the larvae of Prismognathus dauricus Motschulsky, 1860 were investigated using light and scanning electron microscopy. The larvae of P. dauricus are atypical for the following characters: i) the epipharynx possesses anteriorly eleven protophoba arranged in a semi-round line; ii) the par stridens consists of 31 ± 0.7 (N = 10) subconical teeth arranged in a slightly curved, longitudinal row; iii) the plectrum is composed of 60 ± 1.4 (N = 10) carinae; iv) the claws of thoracic legs are apically blunt and bear four setae. Moreover, the size arrangement of the larval spiracles also provides valuable taxonomic information. Our SEM study reveals larval ultramorphological characters useful for identification of this species for the first time.