RESUMO
Abstract Description of immatures and mating behavior of Liogenys bidenticeps Moser, 1919 (Coleoptera: Melolonthidae: Melolonthinae). Some species of Melolonthinae are associated with several species of cropped plants, with larvae consuming roots and, in some cases, are considered as crop pests. In some agricultural regions of Brazil, larvae of L. bidenticeps are found associated with cultivated plants, and little information is available about this taxon. This study, aiming at expanding the knowledge about the morphology and behavior of this species, provides the description of immatures and mating behavior of adults. The studies were conducted at the experimental farm of the Universidade Estadual de Mato Grosso do Sul in Aquidauana, Mato Grosso do Sul state, Brazil, and the adults were collected with light trap and raised in the laboratory. Mating behavior was documented on video both in the field and under laboratory conditions. Descriptions and illustrations of the third instar larva and pupa are presented. Adults have crepuscular flight activity and their copulation lasts an average of 20.25 min, occurring from 19:00 to 22:00 h. On some occasions, females did not accept males for copulation, indicating an active selection of males by females. Field observations demonstrated that adults feed on Brazilian pepper leaves (Schinus terebinthifolius, Anacardiaceae) and cashew flowers (Anacardium occidentale, Anacardiaceae), where male and female meet each other and copulation occurs.
RESUMO
ABSTRACT Liogenys fusca is a rizophagous insect pest in various crops of economic importance in Brazil. Here we investigated the morphology of immature stages and mating behavior of this species. The redescription of the 3rd instar larvae of L. fusca in this work allows identification and registration of occurrence independently of adults, which occur sporadically in a certain period of the year. Male and female of L. fusca remained confined in the soil during the day and exited between 19:00 and 23:30 h. The copulations occurred between 19:30 and 21:00 h, and were characterized by a typical behavioral sequence. Copulation durations in L. fusca lasted on average 512.23 s. Adults were observed feeding before the copulations on leaves and inflorescences of plant species belonging to the family Anacardiaceae, Myracrodruon urundeuva, Schinus terebinthifolius, Astronium fraxinifolium and Anacardium occidentale.
RESUMO
Biological aspects of Leucothyreus ambrosius Blanchard (Coleoptera, Melolonthidae, Rutelinae). Coleopterans of the family Melolonthidae comprise a large group of species that feed on different food sources, including plant roots, stems, and leaves, in addition to plant materials at different decomposition stages. Several species are found in the genus Leucothyreus, occurring in different regions of Brazil, including the various biomes in the country. Information on the biology of species of the genus Leucothyreus is scarce, therefore, we conducted studies on the biological aspects of Leucothyreus ambrosius Blanchard, 1850. The period of adult occurrence was determined with a light trap installed between a cropped and pasture area in the municipality of Aquidauana, Mato Grosso do Sul State, Brazil. Adults collected in the field were used to form insect pairs and the studies were initiated in the entomology laboratory as the adults began ovipositing. Adults were observed flying in the field from October to December. Eggs were obtained as pairs were formed and a colony was established, the embryonic period lasting 14.6 days on average. The larval period in the 1st instar lasted 21.6 days, in the 2nd instar 19.6 days, and in the 3rd instar, 85.6 days. The head capsule width was 1.48 mm in the 1st instar, 2.44 mm in the 2nd, and 3.83 mm in 3rd larval instar. The pupal stage had an average duration of 35.5 days. The egg to adult period lasted 173.3 days. Morphometric information for the larval and adult stages is presented in this study.