Aspectos biológicos de Leucothyreus dorsalis Blanchard (Coleoptera, Scarabaeidae, Rutelinae)

No Brasil existe uma escassez de informações sobre a bioecologia da maioria das espécies de Scarabaeidae. O objetivo do presente trabalho foi estudar os aspectos biológicos de Leucothyreus dorsalis Blanchard, 1850 em laboratório e a campo. A dinâmica populacional dos adultos foi avaliada de janeiro de 2006 a dezembro de 2007, com uso de armadilha luminosa. Adultos coletados em campo foram mantidos em recipientes de plástico contendo solo e mudas de Brachiaria decumbens Stapf, para obtenção de ovos e dar início aos estudos. Todos os estágios de desenvolvimento foram acompanhados e adultos e imaturos foram mensurados para obtenção de dados biométricos. Foram coletados 3.607 adultos e os picos populacionais de coleta ocorreram em novembro de 2006 e outubro de 2007, com média de 145 e 241 indivíduos coletados, respectivamente. O período embrionário durou em média 15,5 dias, o primeiro instar 32,4 dias, o segundo 38,9 dias, o terceiro 52,7 dias, a fase de pré-pupa 130,7 dias, a fase pupal 23,5 dias e a longevidade 18 dias. O ciclo biológico completou-se em 273,5 dias, o que caracteriza a espécie como univoltina. Verificou-se que do primeiro ao terceiro instar houve um aumento de 4,5 vezes no comprimento e de 3,5 vezes na largura das larvas. Observou-se um aumento de 53,1 vezes no peso larval do primeiro para o terceiro instar. As pupas das fêmeas foram significativamente maiores e mais pesadas que a dos machos. As fêmeas adultas foram maiores que os adultos machos, porém, apresentaram peso semelhante.

The effect of sub-lethal doses of Azadirachta indica (Meliaceae) oil on the midgut of Spodoptera frugiperda (Lepidoptera, Noctuidae)

The fall armyworm, Spodoptera frugiperda, is one of the major field pests for maize production. It is mainly controlled by means of synthetic, and more recently by resistant cultivar of maize expressing Bt toxins. The neem tree, Azadirachta indica, is a plant that can potentially control insects with the advantage of being food and environmental safe. The aim of this study was to assess the effect of neem oil on the development and survival of S. frugiperda caterpillars by assessing histological alterations caused on their midgut. Newly hatched caterpillars were submitted to three neem oil concentrations: 0.006; 0.05; 0.4%, which were added to their artificial diet. Ten 3rd instar caterpillars, taken from each treatment, were submitted to histological analysis. The alimentary canals from the specimens were fixed in Baker for 12 hours, desiccated and diaphanized in alcohol/xylol (1:1) and xylol. After placing the samples in paraffin, they were sliced in 8 µm sections and stained with hematoxylin-eosin stain. The neem oil added to the diet of S. frugiperda caused total mortality at dose of 0.4% whilst still in the first instars, prolonged the larval and pupal stages, and reduced the pupal weight. Histo-physiological alterations such as degeneration of the epithelial lining of the midgut and in the peritrophic matrix were found at all concentrations of neem oil.

Imaturos de Sarsina violascens (Herrich-Schäffer) (Lepidoptera, Noctuidae, Lymantriinae)

Imaturos de Sarsina violascens (Herrich-Schäffer) (Lepidoptera, Noctuidae, Lymantriinae). Sarsina violascens é uma espécie polífaga que eventualmente se alimenta de P. cattleianum Sabine (Myrtaceae) durante sua fase larval. Neste estudo são descritas a morfologia e o comportamento dos imaturos, com ilustrações, fotografias e imagens de microscopia eletrônica de varredura.

Temporal distribution of Aedes aegypti Linnaeus (Diptera, Culicidae), in a Hospital in Cuiabá, State of Mato Grosso, Brazil

This study aimed at registering and monitoring the presence of Aedes aegypti in the University Hospital Júlio Muller, Cuiabá-MT, as well as investigating the influence of temperature and rainfall on its temporal distribution and egg densities in ovitraps. The study was performed from April/2007 to March/2008, utilizing ovitraps with 10% of hay infusion and a wood paddle as an oviposition substrate. For surveillance, one ovitrap was placed in each of the 12 points distributed throughout the hospital. Ovitraps were collected monthly at the end of a 5-day installation period. After egg counting, wood paddles were immersed in water to allow larval eclosion for species identification through optical microscopy. Egg Density Index (EDI), Positive Ovitraps Index (POI), and Mean Number of Eggs (MNE) were used for data analysis. The presence of A. aegypti in the hospital was registered throughout the study period, except in July. The MNE was proportionally higher in the internal area (n= 8.47 eggs/paddle) when compared to the external area (n= 5.46 eggs/paddle), and was higher in September/October 2007 and January/February 2008. A significant increase in EDI, POI and MNE was registered in periods where the average temperature was higher, and the increase in POI was also concomitant with an increase in rainfall. The continuous presence of A. aegypti in the hospital throughout the study period, points out the need of including this mosquito in the arthropod control list in this environment. This is particularly important, considering that A. aegypti is an important vector of several arboviroses.

Desarrollo y distribución de huevos y larvas de Merluza, Merluccius gayi (Guichenot) en la costa peruana

Descripción de desarrollo embrionario y larval, incluyendo morfometría y osificación de la merluza peruana, incluye datos de distribución y abundancia de huevos y larvas de esta especie en los años 1966 y 1967 en el litoral peruano. El área considerada para el estudio comprendió gran parte de la costa peruana desde 03°57' a 21°03 de Latitud Sur y con una distancia máxima de algo más de 300 millas fuera de la costa en algunos perfiles.

Effects of sex, host-plant deprivation and presence of conspecific immatures on the cannibalistic behavior of wild Ascia monuste orseis (Godart) (Lepidoptera, Pieridae)

Effects of sex, host-plant deprivation and presence of conspecific immatures on the cannibalistic behavior of wild Ascia monuste orseis (Godart) (Lepidoptera, Pieridae). The specialist cabbage caterpillar Ascia monuste orseis (Lepidoptera, Pieridae) feeds on plants of the Brassicaceae family, but may eventually ingest conspecific eggs and larvae during the larval stage. The present study examines feeding behavior of 4th and 5th instar cabbage caterpillars in relation to sex, host-plant deprivation and presence of conspecifics. We recorded number of egg ingested per larvae, developmental indices and duration of feeding, exploratory and resting behavior. Kale deprived caterpillars presented high rates of cannibalism, development delay and decreased fecundity. Cannibalism rates were not influenced by the sex of the larvae. In general, the presence of conspecific eggs did not interfere with the frequency and duration of the categorical behavioral events. We conclude that food availability is a strong factor influencing the extent to which A. monuste orseis caterpillars cannibalize.

Analysis of digestive tract content of the larvae of Polybia scutellaris (White) (Hymenoptera, Vespidae)

Polybia scutellaris (White, 1841) is a social wasp of biological interest for its role as pollinator and maybe as biological control agent of sanitary and agricultural pests. This study examines the digestive tract contents of the larvae of P. scutellaris from four nests in Magdalena (Buenos Aires province, Argentina). Contents included both animal (arthropod parts) and plant (pollen, leaf and fruit epidermis) parts. The pollen content analysis showed that the wasps visited 19 different taxa of plants during the last active period of the colony before the nests had been collected. The range of sources used by P. scutellaris allows us characterizing the species as a generalist flower visitor. Wasps visited both native and exotic plants located nearby the nest. Most of the epidermal plant remains found in the larval digestive tract belonged to Malvaceae, a family not exploited by the studied colonies as pollen source.

Influence of different tropical fruits on biological and behavioral aspects of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera, Tephritidae)

Influence of different tropical fruits on biological and behavioral aspects of the Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera, Tephritidae). Studies on Ceratitis capitata, a world fruit pest, can aid the implementation of control programs by determining the plants with higher vulnerability to attacks and plants able to sustain their population in areas of fly distribution. The objective of the present study was to evaluate the influence of eight tropical fruits on the following biological and behavioral parameters of C. capitata: emergence percentage, life cycle duration, adult size, egg production, longevity, fecundity, egg viability, and oviposition acceptance. The fruits tested were: acerola (Malpighia glabra L.), cashew (Anacardium occidentale L.), star fruit (Averrhoa carambola L.), guava (Psidium guajava L.), soursop (Annona muricata L.), yellow mombin (Spondias mombin L.), Malay apple (Syzygium malaccense L.), and umbu (Spondias tuberosa L.). The biological parameters were obtained by rearing the recently hatched larvae on each of the fruit kinds. Acceptance of fruits for oviposition experiment was assessed using no-choice tests, as couples were exposed to two pieces of the same fruit. The best performances were obtained with guava, soursop, and star fruit. Larvae reared on cashew and acerola fruits had regular performances. No adults emerged from yellow mombin, Malay apple, or umbu. Fruit species did not affect adult longevity, female fecundity, or egg viability. Guava, soursop, and acerola were preferred for oviposition, followed by star fruit, Malay apple, cashew, and yellow mombin. Oviposition did not occur on umbu. In general, fruits with better larval development were also more accepted for oviposition.

A new case constructing adelid moth from Chile (Lepidoptera)

A new case constructing adelid moth from Chile (Lepidoptera). The adult and larva of Ceromitia tubulifolia sp. nov. are described and illustrated. The larvae seem to be associated with sclerophyllous forest of central Chile. The larvae make a protective case from of a piece of leaf. The name phylloikos is proposed for this form of larval case. A review of the morphology and bionomics of this species are provided.

Descrição da larva de último instar e pupa de Epacroplon cruciatum (Aurivillius) (Coleoptera, Cerambycidae, Cerambycinae) e notas biológica

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.

Nesting and use of pollen resources by Tetrapedia diversipes Klug (Apidae) in Atlantic Forest areas (Rio de Janeiro, Brazil) in different stages of regeneration

Nesting and use of pollen resources by Tetrapedia diversipes Klug (Apidae) in Atlantic Forest areas (Rio de Janeiro, Brazil) in different stages of regeneration. The nesting in trap-nests and use of pollen sources in larval food by Tetrapedia diversipes Klug, 1810 (Apidae) was compared between regenerating areas of Atlantic Forest. The study was conducted between April 2008 and October 2009 at União Biological Reserve, Rio de Janeiro, Brazil. T. diversipes nested in 66 trap-nests and showed a peak of nesting during the months of highest rainfall. The most frequent pollen type in brood cells during the wet season was Dalechampia sp. 1. During the dry season, the type Ludwigia sp. was the most frequent, followed by Dalechampia sp. 2. The high frequency of Dalechampia and Ludwigia species in the larval food, observed in both habitats and in the two seasons could be considered relevant for T. diversipes, suggesting highly selective diet based primarily on two plant species unrelated, but similar in size of pollen grains.

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions

Development of the immature stages of Culex (Culex) saltanensis Dyar (Diptera, Culicidae) under laboratory conditions. Culex (Culex) saltanensis Dyar, 1928 is becoming frequent and abundant in natural and artificial breeding sites in urban and rural areas of Brazil. This study contributes to the knowledge of the biology of a Brazilian strain of C. saltanensis. The development of specimens reared individually or grouped was observed. The study was conducted at a constant temperature of 27 ± 2°C, 14L:10D photoperiod and 80 ± 5% relative humidity. The immature stages were observed every 6 hours until adult emergence, which occurred in 12.29 days among individually reared specimens and in 13.12 days among group-reared specimens. Egg rafts for the experiment were obtained from the laboratory and field. Eggs hatched at a rate of 97.48 ± 2.32%. More eggs per egg raft were obtained from the field than from the laboratory. Males from individually reared specimens emerged in 12.29 ± 1.11 days and females in 13.12 ± 1.58 days. The male-female ratio was 1:1. Larval survival rate was higher than 85% for larvae reared isolated and higher than 95% for group-reared larvae. The Culex saltanensis life cycle was completed within 12 to 14 days, where larval instars I and IV took the most time to develop and the pupae, the shortest.

Intra-puparial development of the females of Chrysomya albiceps (Wiedemann) (Diptera, Calliphoridae)

Intra-puparial development of the females of Chrysomya albiceps (Wiedemann) (Diptera, Calliphoridae). The chronology and morphological changes that take place during intra-puparial development of Chrysomya albiceps is described based on 254 specimens reared in the laboratory. Larvae were obtained from the eggs laid by a single female. The pre-pupae were separated according to the reduction of larval length and the degree of pigmentation and sclerotization of the cuticle. After pupation, 10 individuals were fixed in Carnoy's solution and preserved in 70% ethanol, 10 individuals were fixed every 3 hours up to complete the first 24 hours (n = 80), the remaining individuals were fixed every six hours up to the 90th hour (n = 110) when 54 females emerged. The pupae were immersed in 5% formic acid for 48 hours and maintained in 70% ethanol, and then dissected and analyzed. C. albiceps shows four intra-puparial stages, each of which were described and compared with those described for Musca domestica, Calliphora erythrocephala, Sarcophaga bullata, Cuterebra tenebrosa, Oestrus ovis and Dermatobia hominis. Four developmental stages may be described: (1) the larva-pupa apolysis, after three hours; (2) the criptocephalic pupa, after six hours; (3) the phanerocephalic pupa, after nine hours; (4) the pharate pupa, after nine hours. The pharate adult is completely formed after 81 hours.

Fitness cost of resistance to Bacillus thuringiensis in velvetbean caterpillar Anticarsia gemmatalis Hübner (Lepidoptera, Noctuidae)

Selection pressure to obtain resistant genotypes can result in fitness cost. In this study, we report the effects of the selection pressure of a commercial formulation of Bacillus thuringiensis on biological aspects of a Dipel-resistant strain of velvetbean caterpillar, Anticarsia gemmatalis Hübner. Comparisons of Dipel-resistant and susceptible individuals revealed significant differences in pupal weight and larval development time. Both strains (Dipel-resistant and susceptible) were susceptible to Cry1Ac toxin expressed in foliar cotton tissues. Resistant and susceptible strains showed low survival rates of 22.5% and 51.2%, respectively, when fed with Greene diet containing Bt-cotton. Larvae bioassayed after three laboratory generations presented lower survival and less instar numbers than individuals maintained in the laboratory for more than 144 generations. Pupal weight was 9.4% lower and larval development time was 1.9 days longer in the resistant population than in the susceptible strain. Other parameters, such as duration of pupal stage, adult longevity, number of eggs per female, oviposition period, and egg fertility, remained unaffected.

Spatial evaluation of larvae of Culicidae (Diptera) from different breeding sites: application of a geospatial method and implications for vector control

Spatial evaluation of Culicidae (Diptera) larvae from different breeding sites: application of a geospatial method and implications for vector control. This study investigates the spatial distribution of urban Culicidae and informs entomological monitoring of species that use artificial containers as larval habitats. Collections of mosquito larvae were conducted in the São Paulo State municipality of Santa Bárbara d' Oeste between 2004 and 2006 during house-to-house visits. A total of 1,891 samples and nine different species were sampled. Species distribution was assessed using the kriging statistical method by extrapolating municipal administrative divisions. The sampling method followed the norms of the municipal health services of the Ministry of Health and can thus be adopted by public health authorities in disease control and delimitation of risk areas. Moreover, this type of survey and analysis can be employed for entomological surveillance of urban vectors that use artificial containers as larval habitat.