ABSTRACT: Plectris alienaChapin, 1934, a white grub that promotes serious damage to a variety of crops in North America and Australia, has been reported for the first time in Brazil. Larvae and adults of P. aliena were recorded in sugarcane crops in the state of Mato Grosso do Sul, sampled by trenches in the soil with light traps, respectively, during 2012 and 2013. Root consumption was also determined for the first, second and third instar larvae. The species is univoltine; adults were found mainly in Aug and the peak of third instar larval density was in Apr in all fields sampled. Pupae and adults of P. aliena were observed in the soil profile at depths of up to 60 and 80 cm, respectively. Larvae of P. aliena of the second and third instar consumed the primary and secondary roots of sugarcane, causing serious damage. Third instar larvae consumed 916 mg of root fresh matter, representing 72 % of the sugarcane root system. These results assist in furthering the understanding of its larval dynamics in the soil and provide support for Integrated Pest Management.

Abstract Plectris aliena (Coleoptera, Melolonthidae) Chapin is a species already recorded causing serious damage to various cultures in North America and Australia. Although its occurrence has recently been reported in Brazil, information about its distribution, taxonomy, and biology is limited. Thus, this study aims to report this new occurrence of P. aliena in Deodápolis (Mato Grosso do Sul, Brazil), as well as to present bioecological and morphological aspects of this species. In this way, the seasonal distribution and the life cycle was studied in the years 2017 and 2018. The larvae were sampled through trenches made in the soil and reared in the laboratory. Adults were captured using “Luiz de Queiroz” light traps. Adults have body with dense white hairs, antennae with 10 antenomeres; they measure approximately 12 mm in length, and their antennal lamellae are larger for males than females. The larvae reach 30 mm in length in the third stage and pupae show about 19 mm in length. The life cycle of this species is univoltine. Due to the great diversity of Plectris and the scarce information available about this species in South America, this study will facilitate its identification in the field and indicate the best time for monitoring in sugarcane crop.

ABSTRACT A common white grub species associated with a wide range of crops in Southern Brazil has been named as Cyclocephala flavipennis Arrow for over twenty years. This work aimed to revise the identity of this species based on the study of primary types, identified material collected in previous works and descriptions on literature. The confirmed name for this white grub from Southern Brazilian crops was fixed to C. signaticollis Burmeister, an important pest of several no-tilling crops in Argentina, Uruguay and also in Australia, where it was introduced and is widely established. Taxonomical remarks on adults and larvae are included, in conjunction with depicted images of diagnostic characters. The geographical distribution of C. flavipennis from Southern South America is disregarded. New strategies of pest management for C. signaticollis should be assessed in Southern Brazil taking into account all the background of knowledge on this species from the neighboring countries.

ABSTRACT The replacement of natural grassland by cultivated areas might favor the increase in abundance of some root-feeding species such as the white grubs, which may become a constraint for field crop production. This research aimed to assay the population density and geographical distribution of white grubs pest and other species in natural grassland and cultivated areas throughout the Brazilian Pampa biome. White grubs were sampled in 18 locations in both landscape use types and identified. Population density (number of larvae m-2) was calculated for each recorded species and sorted within two groups (pest species and other species), compared between natural grasslands and cultivated areas, as well as among locations. A dendrogram to evaluate species similarity among locations was built based on combined data obtained from both landscape use types throughout the region. In total, 31 species were found in the Brazilian Pampa, and four of them are considered as crop pests: Diloboderus abderus (Sturm, 1826), Euetheola humilis (Burmeister, 1847), Lyogenys fusca (Blanchard, 1830), and Phyllophaga triticophaga Morón & Salvadori, 1998. The average population density of pest species in cultivated areas was less than five larvae m-2, at most of locations. Some species had a wide geographical distribution (e.g. D. abderus and Cyclocephala modesta Burmeister), while other melolontids occurred at only one location. The knowledge of which white grub species are present in a field and its population densities assist farmers to take proper management decisions.

RESUMO: Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae), conhecido popularmente como coró-pequeno, é um inseto amplamente disseminado na região sul do Brasil. Embora seja encontrado com frequência em áreas cultivadas com cereais de inverno não é considerado inseto praga, por alimentar-se preferencialmente de palha e restos de plantas. Entretanto, nos anos de 2015 e 2016 foi identificado como causador de danos em pastagens perenes de inverno em Lages, Santa Catarina, Brasil. Os danos foram observados em reboleiras e promoveram redução na massa e profundidade de raízes, resultando em perda de vigor, senescência acelerada da parte aérea e morte de perfilhos de plantas de Festuca arundinacea Schreb. e Dacytilis glomerata L.

ABSTRACT: Cyclocephala flavipennis Arrow, 1914 (Coleoptera: Melolonthidae), popularly known as white grub, is an insect widely disseminated in the South Region of Brazil. Despite the frequent occurrence of this white grub in areas cultivated with winter cereals, it is generally not considered a pest, since it feeds on straw and dead plant material. However, in 2015 and 2016, this insect has been identified as the damage-causing agent in the perennial winter pastures in Lages, Santa Catarina, Brazil. Damage was observed in patches and caused reduction in root depth and mass, resulting in loss of vigor, accelerated senescence in aerial parts, and death of tillers in Festuca arundinacea Schreb. and Dactylis glomerata L. plants.

O objetivo deste trabalho foi determinar a relação entre a densidade populacional de espécies de corós (Coleoptera: Melolonthidae) reconhecidas como pragas e as outras espécies da mesma família que ocorrem em áreas cultivadas e não cultivadas no planalto, ao norte do Rio Grande do Sul. Foram realizadas amostragens em 23 municípios no período de julho a setembro, nos anos 2009 e 2010, em uma área cultivada e outra sem cultivo. Em cada área, foram abertas trincheiras de 50x25x30cm de profundidade. As larvas coletadas foram identificadas e reunidas em dois grupos: corós-praga e corós de outras espécies. Comparou-se a densidade populacional (no de larvas m-2) entre os dois grupos nas áreas cultivadas e não cultivadas. A densidade de outras espécies foi superior à densidade de espécies-praga, tanto nas áreas cultivadas (9,0 e 3,9 larvas m-2, respectivamente) quanto nas áreas não cultivadas (6,6 e 3,9 larvas m-2, respectivamente). Não há diferença na densidade populacional média de corós-praga entre áreas cultivadas e não cultivadas

This study aimed to determine the relationship between the population density of pest and other species of white grubs (Coleoptera: Melolonthidae) occurring in cultivated and uncultivated fields in the planalto region, in northern Rio Grande do Sul. Sampling was carried through 23 municipalities, from July to September 2009 and 2010 in two areas, one cultivated and another noncultivated, In each area, trenches of 50x25x30cm were opened. Melolontid larvae collected were identified and gathered in two groups: "pest-species" and "other species". Populational density (no of larvae m-2) of the two groups were compared between cultivated and noncultivated areas. The "other species" density was higher than pest community in both cultivated (9,0 e 3,9 larvae m-2) and noncultivated areas (6,6 e 3,9 larvae m-2 respectively). There is no difference between means of pest species population density between cultivated and noncultivated areas

Melolonthidae Leach, 1819 was defined by Endrödi in 1966 as a cosmopolitan group mainly composed by the subfamilies Melolonthinae, Dynastinae, Rutelinae and Cetoniinae. They are formed by phytophagous or phytosaprophagous taxa, unlike other groups of Scarabaeoidea. Despite being commonly used in Latin America since 1976, it is questioned by many authors of morphological and phylogenetic studies that support the North American classification, formed by the above cited subfamilies and the coprophagous Scarabaeinae and Aphodiinae within Scarabaeidae Latreille, 1802. This review aimed to assess the validity of Melolonthidae with modifications. Thus, different classifications used throughout history were gathered as well as analyzes of relationships between different groups of Scarabaeoidea. Taking into account the latest information and with reserve for future studies on comparative morphology and the support of new accurate molecular data, the present work intends to validate the name of the taxon so called Melolonthidae, formed by the clade Dynastinae-Rutelinae-Melolonthinae. It is also suggested to remove Cetoniinae from Melolonthidae and raise it to family category and, by other hand, to test the relationships of Orphninae with the other members of Melolonthidae. Because of the high abundant and diversity taxa, in order to achieve a worldwide taxonomic consensus, phylogenetic analyzes of Melolonthidae with representative samples of all subfamilies and tribus from all over the world are needed using characters of larvae and adults, to confirm their monophyly, and the relationships with other groups of Scarabaeoidea.

La familia Melolonthidae Leach, 1819 fue definida por Endrödi en 1966 como un grupo cosmopolita compuesto principalmente por las subfamilias Melolonthinae, Dynastinae, Rutelinae y Cetoniinae, formadas por taxones con hábitos fitófagos o fitosaprófagos, a diferencia de otros grupos de Scarabaeoidea. A pesar de ser ampliamente utilizada en América Latina desde 1976, esta clasificación es cuestionada por autores de estudios morfológicos y filogenéticos que apoyan la clasificación utilizada en América del Norte, la cual agrupa las subfamilias citadas junto con los Scarabaeinae y Aphodiinae coprófagos dentro de la familia Scarabaeidae Latreille, 1802. La presente revisión tiene como objetivo apoyar la validez de la familia Melolonthidae con modificaciones. Para ello se compararon diferentes clasificaciones utilizadas a lo largo de la historia de la coleopterología, así como los análisis para relacionar los diferentes grupos de Scarabaeoidea que se han publicado recientemente. Con dicha información y a reserva de efectuar nuevos estudios de morfología comparada y de obtener mejores datos con técnicas moleculares para apoyar un análisis filogenético más preciso, en el presente trabajo se propone aceptar como válido el nombre del agrupamiento denominado Melolonthidae constituído por el clado Dynastinae-Rutelinae-Melolonthinae. También se sugiere retirar a los Cetoniinae de aquel grupo y elevarlos a la categoría de familia, así como comprobar las relaciones de la subfamilia Orphninae con respecto a los miembros de la familia Melolonthidae. Finalmente, se indica que para lograr un consenso global sobre la clasificación supragenérica de los Melolonthidae es necesario efectuar análisis filogenéticos con taxones de todas las regiones del mundo, que efectivamente representen la riqueza específica de cada subfamilia y tribu, utilizando caracteres de larvas y adultos para confirmar su monofilia y las relaciones con otros grupos de Scarabaeoidea.

No Brasil, existem registradas aproximadamente mil espécies de corós, destacando-se, dentre os de maior importância, Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae), pelos prejuízos que pode causar aos cultivos agrícolas e a ampla ocorrência geográfica. O trabalho teve por objetivo caracterizar, com uso da geoestatística, a distribuição espacial de larvas de D. abderus. O estudo foi realizado no ano de 2009, em lavouras de aveia nos municípios de São Francisco de Assis, Cruz Alta e Lagoa Vermelha, RS. Os perímetros das áreas foram demarcados com receptor de sistema de posicionamento global, e os grides de amostragem tiveram dimensão de 70x70m. A densidade populacional foi estimada com abertura de uma trincheira em cada ponto amostral. As análises da variabilidade espacial e da dependência espacial foram feitas por meio de semivariogramas e classificadas segundo CAMBARDELLA et al. (1994). Já os mapas foram gerados a partir dos dados de contagem de larvas em campo. Os semivariogramas indicam a presença de dependência espacial nas áreas de avaliação. Os grides de amostragem mostraram-se apropriados para caracterizar a distribuição espacial de larvas de D. abderus. A distribuição espacial de D. abderus é agregada e seu conhecimento pode melhorar o manejo da praga.

In Brazil, there are about a thousand recorded species of white grubs, and among them the most important is Diloboderus abderus Sturm, 1826 (Coleoptera: Melolonthidae), because of the damage caused to agricultural crops and the wide geographic occurrence. The study aimed to characterize, using geostatistical, the spatial distribution of larvae of D. abderus. The study was conducted during 2009 in oat crops in the counties of São Francisco de Assis, Cruz Alta and Lagoa Vermelha, RS. The perimeters of the fields were delimited with global positioning system receptor, and the sampling grids dimensions were 70x70m. The population density was estimated by opening a trench in each sampling point. The analysis of spatial variability and spatial dependence were made by semivariograms and classified from CAMBARDELLA et al. (1994). Maps were generated from the counting data of larvae in the field. The semivariograms indicate the presence of spatial dependence in the assessment areas. The sampling grids proved to be suitable to characterize the spatial distribution of D. abderus larvae. The spatial distribution of D. abderus is aggregated and this knowledge may improve pest management.

É importante quantificar a densidade populacional de corós para definir o momento adequado para o controle da praga. Assim, o objetivo deste trabalho foi determinar o tamanho de amostra (número de trincheiras por hectare) para a estimação da média de densidade populacional de corós em áreas de campo nativo e de cultivo em diferentes locais do Estado do Rio Grande do Sul. Foram coletados dados de densidade populacional de corós, independentemente de espécie, em áreas de campo nativo e de cultivo em 17 locais, por meio de contagens realizadas em trincheiras de 20cm x 50cm com 30cm de profundidade. Em cada uma das 34 áreas amostradas, calcularam-se medidas de tendência central, de variabilidade, de assimetria e de curtose, e testou-se a normalidade dos dados. Em seguida, verificou-se a homogeneidade de variâncias entre as áreas em cada local e entre os locais em cada área. Depois, calculou-se o tamanho de amostra em cada área e local. O tamanho de amostra (número de trincheiras por hectare) para a estimação da média de densidade populacional de corós é dependente da área (campo nativo ou de cultivo) e do local. Para as áreas e os locais estudados, 61 trincheiras por hectare são suficientes para estimar a média de densidade populacional de corós, para um erro de estimação igual a 30% da média estimada, com grau de confiança de 95%.

It is important to quantify the population density of white grub to set the appropriate time to control the pest. The aim of this study was to determine the sample size (number of trenches per hectare) to estimate the average population density of white grubs in native and cultivated areas in different locations of Rio Grande do Sul State, Brazil. Data were collected from white grubs' population density in native and cultivated areas of 17 locations, regardless of species, through counts in trenches 20cm x 50cm dug to a depth of 30cm. In each of the 34 areas sampled, the central tendency, variability, asymmetry and kurtosis was calculated and the normality data were tested. Then it was verified the homogeneity of variance among areas in each locality and among locations in each area and it was determined the sample size to estimate the average population density of white grubs in each area and locality. The sample size (number of trenches per hectare) to estimate the average population density of white grubs is dependent on the area (native or cultivated) and locality. It was concluded that 61 trenches per hectare are enough to predict the average population density of white grubs, with an estimation error equal to 30% of estimated average, with a degree confidence of 95%.