ABSTRACT
Abstract Background: Scorpionism is a worldwide problem that has already made thousands of victims, and multi-disciplinary approaches for controlling their populations are to be more successful. Hens are often mentioned as tools for controlling scorpions; however, systematic/experimental behavioral studies are not available. Moreover, there is no systematic information on the effect of scorpion venoms on hens. Using the venomous yellow scorpion Tityus serrulatus, the present study aimed to clarify the following aspects: (1) voracity of hens, (2) how hens react when stung, (3) the effect of scorpion stings on hen behavior during attacks, and (4) hen survivorship after feeding on scorpions. Methods: We attracted hens with corn powder, offered them scorpions and then recorded the hen-scorpion interaction. To test the effects of the sting we manually removed the scorpions telson. Results: We found that some hens ate up to six scorpions within minutes. By means of an ethogram and drawings, we showed that they exhibited several aversive behaviors when capturing scorpions. Removal of the scorpion telson stopped the aversive reactions, which was not observed in the control group. Finally, hens did not exhibit atypical behaviors after 1, 7 and 30 days and were all alive after 30 days. Conclusion: This is the first empirical and video recorded study providing evidence that hens are clearly affected by scorpion venom but do not die. Therefore, they may have potential to be used in biological control of these arthropods.
ABSTRACT
Scorpionism is a worldwide problem that has already made thousands of victims, and multi-disciplinary approaches for controlling their populations are to be more successful. Hens are often mentioned as tools for controlling scorpions; however, systematic/experimental behavioral studies are not available. Moreover, there is no systematic information on the effect of scorpion venoms on hens. Using the venomous yellow scorpion Tityus serrulatus, the present study aimed to clarify the following aspects: (1) voracity of hens, (2) how hens react when stung, (3) the effect of scorpion stings on hen behavior during attacks, and (4) hen survivorship after feeding on scorpions. Methods: We attracted hens with corn powder, offered them scorpions and then recorded the hen-scorpion interaction. To test the effects of the sting we manually removed the scorpion's telson. Results: We found that some hens ate up to six scorpions within minutes. By means of an ethogram and drawings, we showed that they exhibited several aversive behaviors when capturing scorpions. Removal of the scorpion telson stopped the aversive reactions, which was not observed in the control group. Finally, hens did not exhibit atypical behaviors after 1, 7 and 30 days and were all alive after 30 days. Conclusion: This is the first empirical and video recorded study providing evidence that hens are clearly affected by scorpion venom but do not die. Therefore, they may have potential to be used in biological control of these arthropods.(AU)
Subject(s)
Animals , Scorpion Venoms/poisoning , Biological Products , Scorpion Stings , Scorpions , Chickens/metabolism , Zea maysABSTRACT
ABSTRACT In this work, the wasp Brachymeria podagrica is recorded for the first time for Colombia, a solitary parasitoid of larvae of the Peckia collusor fly. Third instar larvae of P. collusor were exposed to outdoor ambient conditions for 6 hours in the garden of the Tecnológico de Antioquia (Medellín, Colombia). 29 B. podagrica adults were obtained from the host pupae. Prevalence of parasitism was 14.5 %.
RESUMEN En este trabajo se reporta por primera vez a la avispa Brachymeria podagrica para Colombia y como parasitoide solitario de larvas de la mosca Peckia collusor. Los enemigos naturales fueron atraídos al exponer 200 larvas de P. collusor en tercer instar a condiciones ambientales naturales durante 6 horas el 16 de abril de 2015 en el jardín del Tecnológico de Antioquia (Medellín, Colombia). Como resultado, 29 adultos de B. Podagrica emergieron de las pupas. La prevalencia de parasitismo fue del 14,5 %.
ABSTRACT
Nitrogen is one of the most frequently used fertilizers in growth of Chinese medicinal plants(CMP). As in many other ecosystems, CMP ecosystem is also composed of plant-herbivore-natural enemy(tritrophic) interactions. Nitrogen fertilizer influences the growth and reproduction of CMP, and it is also able to heavily shape the ecosystem functions of CMP ecosystem through bottom-up forces. Understanding the specific effects of nitrogen fertilizer towards each trophic level will be beneficial to improve the resistance of CMP to herbivore and enhance the control efficiency of nature enemies to herbivore, and eventually, maximize the yield and quality of CMP. Most papers published on nitrogen use in plants focused mainly on the impact of nitrogen fertilization on CMP yield and quality. Influences of nitrogen application on CMP ecosystem get little attention at present. Therefore, this review summed up the potential effects of nitrogen fertilization on CMP ecosystem from perspectives of soil and tritrophic interactions. First of all, nitrogen fertilizer might decrease soil microbial biomass and altered the community structures of soil bacteria, fungi and protozoa. Negative effects of nitrogen fertilizer were found on biodiversity of soil bacteria and protozoa. Different fungi species respond differently to nitrogen fertili-zers. Nitrogen deposition can also decrease the soil pH. Decreases in soil microbial diversity and soil acidification can cause negative effects on CMP growth. In addition, nitrogen fertilizer could regulate the pest resistance of CMP including constitutive and inducible resistance. Both positive and negative effects of nitrogen application were found on pest resistance of CMP. Moreover, the development and predation of natural enemies were influenced by nitrogen deposition. Nitrogen influences natural enemies in many ways including plant volatiles, plant nutrient and structure and the supplementary food quality. Nectar and honeydew of plants and preys serve as important food source for natural enemies especially in early season when preys are still not available. Finally, the interactions between herbivores and their natural enemies were also shaped by nitrogen fertilizer in many aspects like increasing the nutritional content of prey and changing control efficiency of natural enemies. Some herbivores have evolved a strategy to sequester secondary metabolites which they absorbed from plant during their feeding. Studies showed that sequestration efficiency of secondary metabolites in prey could also be regulated by nitrogen. Parasitic, emergence, reproduction rate and longevity of parasites were found positively correlated with nitrogen deposition. Hopefully this study will shed light on practicable and economical application of nitrogen in cultivation of CMP.
Subject(s)
China , Ecosystem , Fertilizers , Nitrogen , Plants, Medicinal , SoilABSTRACT
In the present context of pest management in major crops, as the nature of pest pressure evolves, the requirement of new research-based tactics for pest control becomes a continuous process. Insecticide chemistry plays a major, if not dominant role in these developments. In this review, the toxicological aspects of new novel insecticides against crop pests and their selectivity to natural enemies have been discussed.The progress achieved in toxicological research has introduced new insecticides in crop protection during last two decades which are quite different over the existing groups in terms of chemistry and mode of action. It is evident from their mode of action that these chemicals target alternate physiological and biochemical effect. However, it is important to maintain the diversity in chemistry of insecticides for maximizing flexibility, precision and stability in pest management. In recent years, several new insecticide groups viz., neonicotinoids, butenolides, tetronic and tetramic acid derivatives, oxadiazines, diamides, ketoenols, phenylpyrazoles, pyridines, flonicamid, mitochondrial electron transport inhibitor (METI) acaricides, diafenthiuron, tetrazines, oxazolines, and insecticides from soil microorganisms such as avermectins, milbemycins, spinosyns, pyrrole insecticides and insect growth regulators (IGRs) have been discovered and commercialized for agricultural pest management. The ability of these new groups of insecticides to be effective at low rates or doses, high level of selectivity, greater specificity to target pests along with low toxicity to non-target organisms and the environment, replaced many conventional compounds. The conservation of beneficial organisms like natural enemies and pollinators is the fundamental principle of integrated pest management (IPM). Majority of new insecticide groups are safer and fit well into IPM. It is perceived that in the process of entry of new chemical insecticides in crop protection there is a gradual shift from traditional chemicals to selective novel groups which have minimal side-effects on natural enemies of the pests. These selective insecticides have less adverse impact on the conservation and multiplication of bio agents which can be used in a compatible manner with other tools of IPM. The new chemistries are emphasizing to account separately for possible non-target effects on predators, parasitoids, and pathogens. These factors are becoming increasingly important as the agricultural sector moves away from highly persistent broad-spectrum insecticides to more selective rapidly decaying products.
ABSTRACT
Abstract A new species of Diolcogaster (Hymenoptera: Braconidae) is described and illustrated. Additionally, its position within the recently published key to New World species of the xanthaspis species-group (to which the described Diolcogaster belongs) is provided. The gregarious larval parasitoid Diolcogaster choi sp. nov. was collected in Maringá, Paraná State, Brazil. This natural enemy was recovered from a caterpillar of Hypercompe cunigunda (Stoll, 1781) (Lepidoptera: Erebidae) that was feeding on plant of passionflower, Passiflora edulis Sims (Passifloraceae). The fauna of the xanthaspis group in the New World now includes five species, including the new species from Brazil described in this paper. Diolcogaster choi sp. nov. differs anatomically, and is morphologically diagnosed, from all other known member of the xanthaspis group of the genus Diolcogaster, to which it belongs. The species also differs in recorded host, and its DNA barcode appears to be distinctive among described Diolcogaster.
ABSTRACT
Ants (Hymenoptera, Formicidae) are an efficient group of insects as predators of various arthropods. Based on records of the predatory ant activity, a survey was carried out on the efficiency in predation of Anastrepha fraterculus (Diptera: Tephritidae) larvae, considering the percentage of removal of larvae using the variables of soil density and moisture content and their effect on the larvae burying. For this, A. fraterculus larvae were released to the soil and observed for 10 min while burying or removed by the ants in a peach (Prunus persica, Rosaceae) orchard. Eight ant species were recorded removing 32.70% of the larvae. Solenopsis saevissima was the most efficient species, with 42.86% of larvae removal. There were no significant correlations between the predation by ants with soil density and soil moisture content. Despite this, the study pointed out that ants belong to genera Pachycondyla, Pheidole, Pogonomyrmex and Solenopsis can be predators on A. fraterculus larvae, with emphasis on the S. saevissima. These ants can contribute as important agents of conservative biological control of the population of A. fraterculus in peach orchard and their conservation becomes interesting to use of combined control methods aiming to reduce insecticides and aggressive soil management methods.
Formigas (Hymenoptera, Formicidae) são eficientes como predadores de diversos artrópodes. Baseado nos registros de atividade predatória de formigas, um levantamento da eficiência na predação de larvas de Anastrepha fraterculus (Diptera: Tephritidae) considerando a porcentagem na remoção das larvas pelas formigas frente às variáveis de densidade e teor de umidade do solo e o seu efeito sobre o tempo de enterramento das larvas, foi realizado. Larvas de A. fraterculus foram liberadas ao solo e observadas por 10 min enquanto enterravam-se ou eram removidas pelas formigas em um pomar de pessegueiro (Prunus persica, Rosaceae). Oito espécies de formigas foram registradas removendo 32.7% das larvas oferecidas. Solenopsis saevissima foi a espécie mais eficiente com 42.9% da remoção de larvas. Não ocorreram correlações significativas entre os registros de predação por formigas com a densidade e o teor de umidade do solo. Apesar disso, o estudo apontou que as formigas pertencentes aos gêneros Pachycondyla, Pheidole, Pogonomyrmex e Solenopsis podem ser predadoras de larvas de A. fraterculus, com ênfase na espécie S. saevissima, podem contribuir como importantes agentes de controle biológico conservativo da população de A. fraterculus em pomar de pessegueiro e que sua conservação torna-se interessante frente ao uso de métodos de controle combinados visando a redução de inseticidas e de métodos agressivos de manejo do solo.
Subject(s)
Ants , Pest Control , DrosophilaABSTRACT
The incidence of lepidopteran defoliants is one of the environmental factors that regulate the productivity of cultivated forests. The parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae) has significant importance for its efficiency in the parasitism of pupae of these Lepidoptera. The objective of this study was to evaluate the development and reproduction of P. elaeisis in different densities of pupae of Spodoptera frugiperda (Lepidoptera: Noctuidae) at different ages. Pupae of 24, 48, 72 and 96 hours were exposed at densities of 1:1, 4:1, 10:1, 19:1, 31:1 and 46:1 parasitoids/host, respectively. The parasitoids remained in contact with the pupae for 72 hours in 500 mL plastic pots, conditioned in an air-conditioned room, with temperature of 25 ± 2°C, relative humidity of 70 ± 10% and photoperiod of 12 hours. It was concluded that the density of 10:1 presented great results of parasitism, and further increase of density was not needed. Pupae of 24 and 48 hours had a higher percentage of emergence. Biological variables were affected neither by parasitoid densities nor by host age.(AU)
A incidência de lepidópteros desfolhadores é um dos fatores ambientais que regulam a produtividade das florestas plantadas. O endoparasitoide Palmistichus elaeisis (Hymenoptera: Eulophidae) destaca-se pela eficiência no parasitismo e pode ser promissor no controle de Lepidoptera pragas em diversas culturas com importância econômica. Assim, avaliaram-se o desenvolvimento e a reprodução de P. elaeisis em pupas de Spodoptera frugiperda (Lepidoptera: Noctuidae) com idades distintas submetidas a diferentes densidades do parasitoide. Pupas de 24, 48, 72 e 96 horas foram expostas às densidades de 1:1, 4:1, 10:1, 19:1, 31:1 e 46:1 parasitoides/hospedeiro. Os parasitoides permaneceram em contato com as pupas por 72 horas em potes plásticos de 500 mL, acondicionados em sala climatizada com temperatura 25 ± 2°C, umidade relativa de 70 ± 10°C e fotoperíodo de 12 horas. A densidade 10:1 apresentou resultados adequados de parasitismo. Pupas de 24 e 48 horas de idade apresentaram maior porcentagem de emergência. O ciclo de vida, o número de indivíduos emergidos, a razão sexual, a longevidade das fêmeas e o comprimento da cápsula cefálica e da tíbia de P. elaeisis não foram afetados pelas densidades do parasitoide nem pela idade do hospedeiro.(AU)
Subject(s)
Forests , Hymenoptera/parasitology , Lepidoptera , Parasitic Diseases , Pest Control, Biological/methods , SpodopteraABSTRACT
ABSTRACT Coenosia attenuata Stein (1903) is a predatory fly that is commonly found in greenhouses and open fields preying on whiteflies, leafminers, psocopterans and other insects. The species is widespread in the Old World and its distribution has expanded in recent times to Neotropical countries including Chile, Colombia, Costa Rica, Ecuador and Peru. We report here for the first time the presence of C. attenuata in Brazil, occurring in different sites in the State of Ceará (Northeastern Brazil). Expansion of the distribution range of this muscid to the eastern parts of South America opens up the possibility of applying the beneficial predator as a biological control agent for protected crops of the region.
Subject(s)
Animals , Predatory Behavior/physiology , Muscidae/physiology , Pest Control, Biological , Crops, Agricultural/parasitology , Brazil , Introduced Species , Animal DistributionABSTRACT
The use of the parasitoid Neodusmetia sangwani to control the Rhodes grass mealybug Antonina graminis is one of the best examples of classical biological control in the world. The situation could not be different in Brazil, where the pest has also been introduced, and kept under control after the release of its natural enemy. In this review, it is united information with respect to the successful use of a natural enemy in this country. Notes about the description and biology of the insects involved and rearing and release procedures of the parasitoid for the Rhodes grass mealybug control in Brazil will also be presented.(AU)
O uso do parasitoide Neodusmetia sangwani para controlar a cochonilha-das-pastagens Antonina graminis é um dos melhores exemplos de controle biológico clássico no mundo. A situação não poderia ser diferente no Brasil, onde a praga foi introduzida e mantida sob controle após a liberação de seu inimigo natural. Nessa revisão são reunidas informações sobre o bem-sucedido uso de um inimigo natural nesse país. Serão apresentadas também notas sobre a descrição e biologia dos insetos envolvidos e procedimentos de multiplicação e liberação do parasitoide para o controle dessa cochonilha no Brasil.(AU)
Subject(s)
Pest Control, Biological , Hemiptera , Brazil , PastureABSTRACT
ABSTRACT In two independent bioassays, size and flight ability of parasitoids reared on eggs of Corcyra cephalonica for 19 generations and parasitoids reared on a natural host (Spodoptera frugiperda eggs) for 250 generations were compared as fast quality control procedures for insect rearing. The size of parasitoids was examined by morphometric analysis using a stereoscope. Length and width of the wings, right hind tibia, and the body of 20 individuals (males and females) were measured. In the analysis of flight ability, parasitoids were divided into three groups: individuals able to fly ("flyers"), individuals that did not fly but had no visible deformation ("walkers"), and individuals with visible deformation ("deformed"). We observed that parasitoids were larger when reared on the natural host than on the factitious host for all evaluated morphological characters. However, there was no significant difference between the treatments regarding the number of "flyers", "walkers" or "deformed" parasitoids. This indicates that even though the rearing of T. remus on a factitious host affects parasitoid size, it does not necessarily affect its flight ability and therefore suggests that C. cephalonica is suitable as a factitious host for mass rearing of T. remus. Other biological parameters still need to be evaluated, such as host finding ability, parasitism capacity, and parasitoid field efficacy in order to provide a more complete picture of the effects caused by a host change. However, because fast laboratory tests are needed in rearing facilities, the one used in this study might be useful to rapidly assess parasitoid quality.
ABSTRACT
La multiplicación sucesiva de parasitoides en hospederos alternativos, puede afectar las características biológicas y comprometer los sistemas de cría masiva de estos. El objetivo de este trabajo fue evaluar la multiplicación de Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) en pupas del hospedero alternativo Bombyx mori (Linnaeus, 1758) (Lepidoptera: Bombycidae), durante tres generaciones. Y si eso afecta su desempeño reproductivo, cuando se cría, posteriormente, en pupas del hospedero natural Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae). Las informaciones obtenidas en este estudio pueden mejorar y facilitar el control biológico de plagas, principalmente, con la utilización de parasitoides, debido a que T. howardi parasita y se desarrolla en pupas de B. mori. De forma general, la multiplicación de T. howardi durante tres generaciones en pupas del hospedero alternativo B. mori no compromete las características biológicas de este parasitoide cuando se multiplica en su hospedero natural D. saccharalis a los efectos de su utilización en programas de control biológico.
The successive multiplication of parasitoids in alternative hosts can affect the biological characteristics and compromise the systems for massive rearing. The aim of this study was to evaluate if the multiplication of Tetrastichus howardi (Olliff, 1893) (Hymenoptera: Eulophidae) in pupae of the alternative host Bombyx mori (Linnaeus, 1758) (Lepidoptera: Bombycidae) for three generations, affects its reproductive performance, when are reared, then in pupae of the natural host Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae). The information obtained in this study can improve and facilitate the biological control of pests, mainly with the use of parasitoids, due to the fact that T. howardi parasite and develops into pupae of B. mori. In general, the multiplication of T. howardi for three generations in the alternative host pupae of B. mori does not compromise the biological characteristics of this parasitoid when multiplied in its natural host D. saccharalis to the effects of their use in biological control programs.
ABSTRACT
Objetivou-se com este trabalho avaliar a seletividade de dezenove agrotóxicos utilizados na cultura do pessegueiro sobre ovos e pupas do predador Chrysoperla externa em condições laboratoriais (temperatura 25±1ºC, umidade relativa 70±10% e fotofase 14 horas). Os agrotóxicos foram pulverizados diretamente sobre ovos e pupas por meio de uma torre de Potter, utilizando a máxima dosagem recomendada para a cultura do pessegueiro. Foi avaliada a viabilidade de ovos e pupas, além da fecundidade e fertilidade de adultos emergidos de pupas tratadas. Os agrotóxicos foram classificados para ovos em função da redução na eclosão e, para pupas, em função do efeito total, conforme a escala de toxicidade proposta pela IOBC. A maioria dos agrotóxicos avaliados (8 inseticidas, 8 fungicidas e 2 herbicidas) se mostrou inócua (classe 1) a ovos e pupas, com redução na eclosão de larvas e efeito total em pupas inferiores a 30%. A exceção se deu para o inseticida óleo mineral, que reduziu a eclosão de larvas em 69,55% quando pulverizado em ovos e proporcionou efeito total em pupas de 36,22%, sendo classificado como levemente nocivo (classe 2) a ovos e pupas de C. externa .
This research aimed to evaluate the effect of nineteen pesticides used in peach orchards on eggs and pupae of the predator Chrysoperla externa in bioassays carried under laboratory conditions (temperature of 25±1ºC, relative humidity 70±10% and 14 hours photophase). The pesticides were directly sprayed on eggs and pupae trough a Potter tower using the maximum recommended dosage for peach orchards. It was evaluated eggs and pupae viability, in addition to fecundity and fertility of adults emerged from treated pupae. The pesticides were classified to eggs according to reduction in eggs hatch, and to pupae according to the total effect into IOBC toxicity categories. Most of pesticides evaluated (8 insecticides, 8 fungicides and 2 herbicides) were harmless (category 1) to eggs and pupae, with a reduction in eggs hatch and total effect to pupae lower than 30%, except for the insecticide mineral oil, which reduced eggs hatch in 69.55% and caused a total effect of 36.22% in pupae, being therefore classified as slightly harmful (category 2) to eggs and pupae of C. externa .
ABSTRACT
No impact of Bt soybean that express Cry1Ac protein on biological traits of Euschistus heros (Hemiptera, Pentatomidae) and its egg parasitoid Telenomus podisi (Hymenoptera, Platygastridae). Biological traits of the stink bug Euschistus heros and its main biological control agent Telenomus podisi were evaluated under controlled environmental conditions (25 ± 2ºC; 60 ± 10% RH; and 14/10 h photoperiod) by placing first instar nymphs into Petri dishes with pods originating from two soybean isolines (Bt-soybean MON 87701 × MON 89788, which expresses the Cry1Ac protein, and its near non-Bt isoline A5547) where they remained until the adult stage. Due to gregarious behavior exhibited by first instar nymphs, they were individualized only when at the second instar. Adults were separated by sex and weighed, and pronotum width of each individual was subsequently measured. They were placed into plastic boxes containing soybean grains of the same soybean isoline as food source. Egg viability and female fecundity were assessed in adult individuals. Adult females of T. podisi (up to 24h old) were placed with eggs of E. heros from mothers reared on both soybean isolines. Nymphal development time, insect weight, pronotum width, sex ratio, female fecundity, and egg viability (% emergence) of Euschistus heros did not differ between treatments. Eggto-adult development time, female longevity, sex ratio, and percentage of parasitized eggs were not impacted by the Bt-soybean (expressing Cry1Ac protein). Results indicate that the Bt-soybean, MON 87701 × MON 89788, has no direct significant impact on the two studied species.
ABSTRACT
Orius insidiosus é um percevejo predador associado à cultura do milho no Brasil. No entanto, poucos estudos relacionam sua biologia e comportamento sobre as pragas-alvo e o efeito indireto do milho Bt através de sua presa O objetivo desse trabalho foi avaliar aspectos biológicos de O. insidiosus alimentado com ovos de Spodoptera frugiperda e o efeito da alimentação dessa presa em milho Bt, expressando a proteína Cry1A(b), nos seus aspectos biológicos e comportamentais. Os ensaios foram conduzidos em câmara climatizada a 25 ± 1 ºC de temperatura, 12 horas de fotoperíodo e 60 ± 10% de umidade relativa. Ovos de O. insidiosus foram retirados da criação de pesquisa mantida em laboratório e ninfas de primeiro ínstar foram isoladas e mantidas de acordo com o tratamento. Para os ensaios com larvas de S. frugiperda que se alimentaram em milho Bt, utilizaram-se plantas nos estádios vegetativos entre V5 e V8. As variáveis avaliadas foram: a sobrevivência de ninfas, 48 h após a emergência e ninfas do 4º e 5º instares; o período de desenvolvimento das ninfas do 4º e 5º ínstares e a não preferência para alimentação entre lavas de S. frugiperda alimentadas em milho Bt e não Bt. O predador completou a fase ninfal em 11,94 dias apenas com alimentação de ovos de S. frugiperda. O primeiro ínstar apresentou sobrevivência menor do que aos demais avaliados. A alimentação de ninfas de O. insidiosus com larvas de S. frugiperda alimentadas em milho Bt e não Bt não afetou significativamente o desenvolvimento nem a sobrevivência do predador, que apresentou uma maior preferência para as larvas que se alimentaram em milho Bt, provavelmente devido ao tamanho reduzidos dessas larvas.
Orius insidiosus is a predator frequently associated with maize crop in Brazil. However there are few studies comparing its biology and behavior on the target pest as well as the Bt maize indirect effect by its pray. Thus, the present study was to evaluate the biological aspects of O. insidiosus feeding on eggs of Spodoptera frugiperda and the effect of the prey feeding on Bt maize expressing Cry1A(b) protein, on its predation ability and development. The experiments were conducted in a climatic chamber at 25 ± 1 oC and photophase of 12 h and 60 ± 10% RH. O. insidiosus eggs were obtained from a laboratory colony and the first instar nymphs were isolated and submitted to the experiment treatments. Larvae of S. frugiperda were fed on leaf of Bt maize on V5 to V8 vegetative growth stages. There were evaluated: nymphal survival after 48 h of hatching and nymphs at 4th and 5th instars. Also the nymphs development period at 4th and 5th instars and non-preference for feeding on S. frugiperda fed on Bt and Non-Bt maize were evaluated. The predator feeding only on eggs of S. frugiperda completed the nymphal stage in 11.94 days. The first instar had lower survival than the others. The development and survival of O. insidiosus nymphs were not affected when they were fed of FAW larvae fed on Bt and Non-Bt maize and the predator preferred to feed on larvae from Bt-maize, probably because they were smaller.
Subject(s)
Containment of Biohazards , Zea mays , Cimicidae , Hemiptera , BiologyABSTRACT
This study reports the occurrence of Pachycrepoideus vindemmiae (Rondani) (Hymenoptera: Pteromalidae) and Spalangia cameroni Perkins (Hymenoptera: Pteromalidae) as parasitoids of Ornidia obesa Fabricius (Diptera: Syrphidae) in poultry farms in Morrinhos, Goiás, state Brazil. Samples of chicken feces were collected at two weeks intervals and taken to the laboratory. The pupae were extracted by water flotation. Each pupa was placed in capsules of gelatin until the emergence of dipterous or their parasitoids. The parasitism percentage of P. vindemmiae and S. cameroni was 5.1 percent.
ABSTRACT
This study aimed to evaluate the effects of (g a.i. L-1) abamectin (0.02), carbaryl (1.73), sulphur (4.8), fenitrothion (0.75), methidathion (0.4), and trichlorfon (1.5) on the survival of larvae and pupae, on the oviposition of adults and hatching of eggs from treated Chrysoperla externa third-instar larvae from two different populations (Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil). Morphological changes caused by abamectin to eggs laid by C. externa from Vacaria population were evaluated by mean of ultrastructural analysis. The pesticides were applied on glass plates. Distilled water was used as control. For the evaluation of larvae mortality, a fully randomized experimental design in a 2 x 7 (two populations x seven treatments) factorial scheme was used, whereas for the effects of the compounds on oviposition capacity and egg viability, a 2 x 4 factorial scheme was used. Carbaryl, fenitrothion, and methidathion caused 100 percent mortality of larvae. Abamectin reduced the hatching of eggs from treated third-instar larvae of both populations; however, this pesticide presented highest toxicity on insects from Vacaria. The ultrastructural analysis showed that abamectin caused malformations in micropyle and in chorion external surface of C. externa eggs. Based in the total effect (E), carbaryl, fenitrothion, and methidathion are harmful to C. externa; trichlorfon is harmless to third-instar larvae, while abamectin and sulphur are harmless and slightly harmful to third-instar larvae from Bento Gonçalves and Vacaria, respectively.
Avaliaram-se os efeitos de (g i.a. L-1) abamectina (0,02), carbaril (1,73), enxofre (4,8) fenitrotiona (0,75), metidationa (0,4) e triclorfom (1,5) sobre a sobrevivência de larvas e pupas, na oviposição de adultos e viabilidade de ovos de Chrysoperla externa de duas populações (Bento Gonçalves e Vacaria, Rio Grande do Sul). Alterações morfológicas causadas por abamectina em ovos depositados por C. externa da população de Vacaria foram avaliadas por meio de análises ultra-estruturais. Os agrotóxicos foram aplicados sobre placas de vidro. Água destilada foi utilizada como testemunha. Para avaliação da mortalidade de larvas utilizou-se delineamento experimental inteiramente ao acaso, em esquema fatorial 2 x 7 (duas populações x sete tratamentos) e para avaliação dos efeitos dos compostos sobre a capacidade de oviposição e viabilidade de ovos utilizou-se esquema fatorial 2 x 4. Carbaril, fenitrotiona e metidationa causaram 100 por cento de mortalidade das larvas. Abamectina reduziu a viabilidade de ovos de C. externa, provenientes de larvas de terceiro ínstar de ambas as populações; entretanto, apresentou toxicidade mais elevada sobre insetos de Vacaria. Análises ultra-estruturais evidenciaram que abamectina causou deformações na micrópila e na superfície externa do córion de ovos de C. externa. Baseando-se no efeito total (E), carbaril, fenitrotiona e metidationa são prejudiciais a C. externa; triclorfom é inócuo, enquanto abamectina e enxofre são inócuos e levemente prejudiciais a larvas de terceiro ínstar oriundas de Bento Gonçalves e Vacaria, respectivamente.
ABSTRACT
Xanthozona melanopyga (Wiedmann, 1830) (Diptera: Tachinidae) is recorded here as a parasitoid of Brassolis astyra Godart, 1824 (Lepidoptera: Nymphalidae). Dipteran endoparasitoids have been recorded as pupal endoparasitoids of Brassolis sophorae (L.), due to the scientific and economic importance of these interespecific relationships, and aiming to increase the knowledge on natural and conservative biological control, I hereby record Xanthozona melanopyga (Wiedmann) as larval-pupal parasitoid of Brassolis astyra Godart for the State of Rio Grande do Sul, Brazil. For the first time.
Xanthozona melanopyga (Wiedmann, 1830) (Diptera: Tachinidae) é registrada como parasitóide de Brassolis astyra Godart, 1824 (Lepidoptera: Nymphalidae). Representantes de Diptera têm sido registrados como endoparasitóides de pupas de Brassolis sophorae (L.). Diante da importância científica e econômica desse tipo de relação interespecífica, visando à ampliação de conhecimentos relacionados ao controle biológico natural e conservativo, o presente registra no Estado do Rio Grande do Sul, a ocorrência de parasitismo por Xanthozona melanopyga (Wiedmann, 1830) como parasitóide larva-pupa em Brassolis astyra Godart, 1824. Pela primeira vez.
ABSTRACT
First report of parasitism on pupae of Opsiphanes invirae amplificatus Stichel (Lepidoptera, Nymphalidae) by Conura (Conura) maculata (Fabricius) (Hymenoptera, Chalcididae) in Rio Grande do Sul, Brazil. This scientific note records the parasitism on pupae of Opsiphanes invirae amplificatus Stichel (1904) by Conura (Conura) maculata (Fabricius). This is a report of this interaction in the subtropical region of South America and the first report of the occurrence of this parasitoid in the state of Rio Grande do Sul, Brazil.
Primeiro registro de parasitismo em pupas de Opsiphanes invirae amplificatus Stichel (Lepidoptera, Nymphalidae) por Conura (Conura) maculata (Fabricius) (Hymenoptera, Chalcididae) no Rio Grande do Sul, Brasil. Esta nota científica registra o parasitismo em pupas de Opsiphanes invirae amplificatus Stichel (1904) por Conura (Conura) maculata (Fabricius). Este é um registro desta interação na região subtropical da América do Sul e o primeiro relato de ocorrência deste parasitóide no estado do Rio Grande do Sul, Brasil.
ABSTRACT
The effects of the egg density of Diaphania hyalinata (L.) on several biological parameters of Trichogramma exiguum Pinto & Platner and T. pretiosum Riley were investigated. For that, 24h-old egg masses were isolated in glass tubes (15 replicates; 1 egg mass = 1 replicate), and offered to parasitization by a newly-emerged female of T. pretiosum or T. exiguum 24h at the proportion of one female to 5, 10, 15, 20, 25, 30, 35 and 40 eggs of D. hyalinata. The following parameters were evaluated: number of parasitized eggs, number of individuals per egg, viability and sex ratio. Trichogramma exiguum parasitized more eggs than T. pretiosum when more than 25 eggs were available per female. The percentage of emergence was satisfactory to T. pretiosum in densities up to 15 eggs/female and up to 20 eggs/female for T. exiguum. The number of individuals per egg was not statistically different in both species except in the density of 25 eggs/female. It can be concluded that T. exiguum performed better than T. pretiosum at larger clutch sizes, as T. exiguum parasitization capacity increased as a result of the size of the host clutch size.