ABSTRACT
ABSTRACT The present study describes the morphology of the antennal sensilla of adults of Gymnetis holosericea (Voet, 1779) and Gymnetis rufilateris (Illiger, 1800). The adults of Gymnetis spp. were sexed and antenna of males and females were dissected. Both species have sensilla chaetica, trichodea, placodea (type I and II), coeloconica (type I and II), and ampullacea (or pore). Females of G. holosericea have a total of about 19,995 sensilla and males have about 23,273 sensilla, and females of G. rufilateris have about 16,633 sensilla and males have about 21,184 sensilla. Sensilla placodea are the predominant type of sensilla in males and females of G. holosericea and G. rufilateris.
ABSTRACT
Abstract: Adults of the beetle Cyclocephala literata Burmeister, 1847 are important pollinators to some Magnoliaceae. Is known that insects could find host plants by detecting volatiles through antennal sensilla. Cyclocephala has its three distal antennomeres lamellate, and the surface of each lamella has sensilla trichodea, chaetica, placodea, coeloconica, basiconica and ampullacea. Three kinds of sensilla placodea were found (type I, II and III), and two kinds of sensilla coeloconica were observed (type I and II). Females have on average 10,776 sensilla, of which 10,214 are sensilla placodea, 536 are sensilla coeloconica, and 26 are sensilla basiconica. Males have on average 10,386 sensilla, of which 9,873 are sensilla placodea, 464 are sensilla coeloconica, and 49 are sensilla basiconica. Males and females have similar quantities of sensilla, and sensilla placodea are predominant. The differences observed in the number of sensilla of males and females were found in other beetles and were attributed to the detection of cospecific sexual pheromones by one of the sexes, or to the detection of plant volatiles. The antennal sensilla of C. literata is described and quantified in present study, and some perspectives about the differences kind of chemical communication, pollination, and antennae dimorphism is discussed.
Resumo: Adultos do besouro Cyclocephala literata Burmeister, 1847 desempenham importantes funções de polinização em plantas da família Magnoliaceae. É conhecido que muitos insetos encontram plantas hospedeiras pela detecção de voláteis pelas sensilas antenais. Cyclocephala possui os três antenômeros distais lamelados e na superfície de cada lamela possuem sensila trichodea, caética, placódea, coelocônica, basicônica e ampulacea. Foram encontrados três tipos de sensilas placódeas (tipo I, II e III), e dois tipos de sensilas coelocônicas (tipo I e II). Fêmeas apresentam em média 10.776 sensilas, das quais 10.214 são sensilas placódeas, 536 são sensilas coelocônicas e 26 são sensilas basicônicas. Os machos apresentaram em média 10.386 sensilas, das quais 9.873 são sensilas placódeas, 464 são sensilas coelocônicas e 49 são sensilas basicônicas. Machos e fêmeas apresentam quantidades semelhantes de sensilas e as sensilas placódeas são predominantes. As diferenças encontradas nas quantidades de sensilas em machos e fêmeas também foram encontradas em outros besouros e foram atribuídas a detecção de feromônios coespecíficos por um dos sexos, ou para detecção de voláteis de plantas. A sensila antenal de C. literata é descrita e quantificada no presente estudo, e algumas perspectivas sobre as diferenças entre os tipos de comunicação química, polinização e dimorfismo antenal é discutido.
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ABSTRACT Species of the scarab beetle genus Liogenys are potential pests to several crops in Brazil. This study aimed to describe the antennal sensilla of Liogenys suturalis (Blanchard, 1851). Adults were collected in a pasture area in Bálsamo, São Paulo state, Brazil, using a light trap. The antennae were dissected and images of the antennal sensilla were obtained using a scanning electron microscope. Sensilla ampulacea (pores), s. auricilica, s. basiconica, s. placodea, and s. trichodea are present in the lamellae. The antenna of females have 4399 sensilla, of which 3671 (83.5%) are s. placodea, 422 (9.5%) s. coeloconica, and 306 (6.9%) s. auricilica. The antennae of males have 4039 sensilla, of which 3117 (77.1%) are s. placodea, 353 (8.7%) s. coeloconica, and 569 (14.1%) s. auricilica. The antennal sensilla of the genus Liogenys have been described for the first time.
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ABSTRACT Antennal sensilla are important functional elements of sensory systems in insects. This study aimed to determine the morphology and structure of the sensilla of two species of the genus Hoplopyga. Adults of Hoplopyga liturata (Olivier, 1789) were collected in traps with sugarcane juice as an attractant. Thereafter, larvae of Hoplopyga albiventris (Gory and Percheron, 1833) were collected in mounds of termites (Cornitermes cumulans (Kollar, 1832) Isoptera). Then, they were reared in the laboratory for adult observations. Antennae of H. liturata and H. albiventris have sensilla chaetica, trichodea, placodea (type I and II), coeloconica (type I and II), and ampullacea (or pore). Females of H. liturata have a total of about 10657 sensilla and males have about 12512, whereas females of H. albiventris have about 16490 sensilla and the males 24565 sensilla. Sensilla placodea are predominant in the antenna of males and females of both species.
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Abstract The genus Cyclocephala is common in Brazil (Coleoptera, Scarabaeidae, Dynastinae). The adults of some species are important pollinators, and the larvae develop in the soil, feed on organic matter, and contribute to nutrient cycle, but immatures of some species feed on plant roots, and some were registered causing damage in crops. The mating process of some phytophagous scarab beetles has a chemical recognition step, and the antenna is the main structure involved in the detection of odorants associated with insect communication. In the present study the mating behavior, life cycle, and antennal sensilla of C. putrida are described. The study was conducted at the Universidade Estadual de Mato Grosso do Sul, Cassilândia, Brazil. Adults were collected by a light trap installed from January 2016 to December 2017 and were taken to the laboratory for studies. Adults swarms are brief and were registered from January to February, and specimens were mostly collected at 20:00 to 22:00h. Chemical recognition may occur at least during one of the mating steps, during which the couple kept their antennae moving and the lamellae open, while females select males. In laboratory, the mating process lasted 7.5 minutes on average. The antennae of females have about 3399 sensilla and males about 4229 sensilla. Sensilla placodea types I, II, and III are the most abundant, and sensilla ampullacea, basiconica, and coeloconica are also present. The embryonic period lasted 16.0 days; first, second and third instars lasted 16.0, 48.3, and 165.3 days, respectively. The pupal period lasted 24.0 days. The period between egg deposition and adult emergency is about 271.5 days.
Resumo O gênero Cyclocephala é comum no Brasil (Coleoptera, Scarabaeidae, Dynastinae). Os adultos de algumas espécies são importantes polinizadores, e a larva desenvolve-se no solo, alimenta-se de matéria orgânica e contribui para a ciclagem de nutrientes, mas imaturos de algumas espécies alimentam-se de raízes de plantas, e alguns são registrados causando danos em plantas cultivadas. O processo de cópula de algumas espécies de Scarabaeidae fitófagos, apresentam reconhecimento químico, e nas antenas aparecem várias estruturas responsáveis pela detecção dos odores envolvidos na comunicação. No presente trabalho o comportamento de cópula, ciclo de vida e sensilas antenais de Cyclocephala putrida são descritos. O estudo foi conduzido na Universidade Estadual de Mato Grosso do Sul, Cassilândia, Brasil. Adultos foram coletados com armadilha luminosa instalada de Janeiro de 2016 a Dezembro de 2017, e levados para laboratório para estudos. Os adultos revoam por curto período de janeiro a fevereiro, e os espécimes foram coletados em maior quantidade das 20:00 às 22:00 h. O reconhecimento químico possivelmente ocorre durante as etapas que envolvem o comportamento de cópula, no qual o casal mantém as antenas em movimento e as lamelas abertas e as fêmeas selecionam os machos. Em laboratório a cópula dura 7,5 minutos em média. As antenas das fêmeas possuem 3399 sensilas e os machos 4229 sensilas, e as sensilas placódeas dos tipos I, II e III, foram as mais abundantes e sensilas ampuláceas, basicônicas e coelocônicas também estão presentes. O estágio de ovo durou 16,0 dias; o primeiro, segundo e terceiro instar duraram 16,0, 48,3 e 165,3 dias, respectivamente. O período pupal durou 24,0 dias. O período entre deposição dos ovos e emergência dos adultos é de 271,5 dias em média.
ABSTRACT
ABSTRACT Some species of Cyclocephala Dejean, 1821 (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini) were reported as crop or pasture pests. Within this genus, Cyclocephla tucumana Bréthes, 1904 was noticed in cultivated areas in South Brazil, 2009 − 2010. Other study found larvae of the species associated with pastures in Aquidauana, Mato Grasso do Sul State (MS), 2009. In the present study, larvae of C. tucumana were collected in pasture areas from August 2015 to July 2016, in Cassilândia, MS. The material was reared in laboratory for the description of immatures, and the regional population was studied to clarify its dynamics. Immatures were abundant throughout the years and are described for the first time. Taxonomic discussion, updated key to larvae and pupae, and a teratological note are also added.
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ABSTRACT The first immature description for a South American species of the genus Chlorota Burmeister, 1844 (Melolonthidae: Rutelinae) is presented. The last larval instar and female pupa of Chlorota paulistana Ohaus, 1912 are described. Illustrations and diagnostic characters are also presented, along with additional characters for the genus, and a new state record for Pernambuco is added. With this study, two species of immatures of Chlorota are now known and their diagnostic characters and differences are here discussed.
ABSTRACT
Abstract: When suitable, adults of Scarabaeidae usually form swarms to find food and breeding sites. The steps of mating behavior can be mediated by chemical communication, and antennal sensilla are released volatiles detection structures, as sexual pheromones. In present work the mating behavior and the antennal sensilla of Anomala inconstans Burmeister, 1844 are described. The study was conducted at the Universidade Estadual de Mato Grosso do Sul, Cassilândia, Brazil from March 2015 to December 2017. Adults were collected through a light trap and taken to the laboratory for studies. Field and laboratory observations provided data for the description of the steps of mating behavior. Adults swarms were registered from September to November 2015 at 05:30 pm to 00:00 am. Females display a calling behavior from 05:25 pm to 08:00 pm, in which they rub their posterior legs against their abdomen, and after a few minutes males are able to locate them. In laboratory, the mating process lasted 20.4 minutes on average, and the possibility of chemical communication between adults was here discussed. The antennae of the species have trichoid, chaetica, placoid types I, II and III, and coeloconic types I and II sensilla. Placoid sensilla are the most abundant and females have more sensilla than males.
Resumo: Em condições adequadas os adultos de Scarabaeidae geralmente realizam revoadas em busca de alimento e áreas de reprodução. As etapas relacionadas ao comportamento de cópula podem ser intermediadas por comunicação química, e os sensilos antenais são as estruturas que detectam os voláteis como os feromônios sexuais. No presente trabalho o comportamento de cópula e os sensilos antenais de Anomala inconstans Burmeister, 1844 são descritos. Os estudos foram conduzidos na Universidade Estadual de Mato Grosso do Sul, Cassilândia, de março de 2015 a dezembro de 2017. Adultos foram coletados com armadilha luminosa e conduzidos para laboratório para estudos. Observações de campo e de laboratório permitiram a descrição das etapas do comportamento de cópula. Os adultos revoaram de setembro a novembro de 2015 das 17:30h as 24:00h. As fêmeas apresentam o comportamento de chamamento das 17:25h as 20:00h, no qual atrita o terceiro par de pernas no abdome e, transcorridos alguns minutos, os machos as localizam. Em laboratório a cópula durou em média 20,4 minutos, sendo verificada a possibilidade de comunicação química entre os adultos. Nas antenas foram encontrados sensilos tricódios, chaéticos, placódios dos tipos I, II e III, e coelocônicos tipo I e II. Os sensilos placódios são os mais abundantes, e as fêmeas possuem mais sensilos do que os machos.
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ABSTRACT Mating behavior and description of immature stages of Cyclocephala melanocephala (Fabricius, 1775) (Coleoptera: Scarabaeidae: Dynastinae), identification key and remarks on known immatures of Cyclocephalini species. Some species of Cyclocephala Dejean, 1821 are regarded as rhizophagous crop pests and others as beneficial species. The objective of this work was to report the mating behavior and to describe the immature stages of C. melanocephala. The studies were developed at the Universidade Estadual de Mato Grosso do Sul in Cassilândia, Mato Grosso do Sul state, Brazil. Adults were collected with a light trap from September to December 2014 and 2015 to carry out studies of mating behavior, breeding, and descriptions of immature stages. Copulation lasted 10.4 ± 4.3 min and took place from 19:00 to 24:00 h. Some females refused males for mating and moved away from them. Regarding flight period, adults were collected in larger quantities from 20:00 to 23:00 h. Identification keys to immatures of three genera of Cyclocephalini, including several Cyclocephala species are presented.
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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.
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Lagochile emarginata (Gyllenhal): morphology of immature and imago, and biological records (Coleoptera, Scarabaeidae, Rutelinae). The last larval instar and pupa of Lagochile emarginata are described. Pupa of the genus Lagochile Hoffmannsegg, 1817 is described for the first time. Redescription of the imago, clarifications on the morphology of immature Scarabaeoidea and biological notes are presented.
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Description of the third larval instar and pupa of Geniates barbatus Kirby (Coleoptera, Scarabaeidae, Rutelinae). The last larval instar and pupa of the Neotropical Geniatini Geniates barbatus Kirby, 1819 are described and illustrated. Biological notes and a key to the third instar larvae of Neotropical Rutelinae are also provided.
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Description of last larval instar and pupa of Epacroplon cruciatum (Aurivillius) (Coleoptera, Cerambycidae, Cerambycinae) and biological notes. Last larval instar and pupa of South American Hexoplonini Epacroplon cruciatum (Aurivillius, 1899) are described and illustrated. Biological notes are also presented.
Descrição da larva de último instar e pupa de Epacroplon cruciatum (Aurivillius) (Coleoptera, Cerambycidae, Cerambycinae) e notas biológicas. Último instar larval e pupa do Hexoplonini sul-americano Epacroplon cruciatum (Aurivillius, 1899) são descritos, ilustrados e disponibilizadas notas biológicas.