Insecticidal potential of organic extracts of Calotropis procera to Spodoptera frugiperda

This study evaluated the toxic effects of organic extracts of Calotropis proceraleaves on the survival, development, and reproduction of Spodoptera frugiperda. Solutions of crude methanol extract and hexane and methanol fractions of C. proceraleaves were added at 1.15% and 2.14% concentrations to the artificial diet of S. frugiperda. The mortality and duration of larval and pupal phases, weights of female and male pupae, deformations of pupae and adults, the reduction of adults able to reproduce, pre-oviposition and oviposition periods, the number of postures per female, and the fecundity and fertility of S. frugiperdafemales were also evaluated. The extracts harmed the survival, development, and reproduction of S. frugiperda. The ingestion of extracts and fractions by caterpillars affected adults by decreasing the oviposition period, the number of postures, fecundity, and fertility. The crude MeOH extract at a2.14% concentration harmed the evaluated parameters of the insect, except for pupal mortality, female pupae weight, and pre-oviposition period. The MeOH fraction at 2.14% caused a 50.0% mortality of caterpillars and 16.0% deformation in pupae and 33.0% inadults, reducing by 72.0% the population able to reproduce. The MeOH fraction at the 2.14% concentration caused 25.0% and 38.0% of pupal mortality and deformation, respectively. Calotropis procerahas promising insecticidal properties for a biological insecticide, a convenient and sustainable strategy for protecting plants against S. frugiperda.

Anatomical and histochemical descriptions of the male reproductive system of Diachasmimorpha longicaudata (Ashmed) (Hymenoptera: Braconidae)

ABSTRACT The parasitoid Diachasmimorpha longicaudata is an important control agent for several species of fruit flies. Research on the characteristics of the reproductive system and reproductive biology of this parasitoid can be valuable for studies in taxonomy and phylogeny of insects of the order Hymenoptera. In this study we analyzed the histology and histochemistry of the male reproductive system of D. longicaudata. In this species the male reproductive system consists of a pair of testes, two accessory glands, and an ejaculatory duct. Each testicle consists of only one follicle. The testicular follicles are filled with cysts in different stages of spermatogenesis. Histochemical analyses detected proteins and carbohydrates in the cytoplasm of secretory cells and in the lumen of accessory glands. The morphology of the male reproductive system of D. longicaudata differs in some respects from other species of Hymenoptera.

Density of Diachasmimorpha longicaudata (Ashmead) and host Ceratitis capitata (Wied) larvae for the increase of parasitoid female production / Densidade de Diachasmimorpha longicaudata (Ashmead) e do hospedeiro Ceratitis capitata (Wied) no incremento da produção de fêmeas do parasitoide

The objective of the present study was to evaluate the ratio of Ceratitis capitata larvae/female of Diachasmimorpha longicaudata that results in the increase of parasitism and the production of females in the progeny. We used 8-day-old copulated D. longicaudata females with oviposition parasite experience and third instar larvae of C. capitata from rearing stock maintained at the Laboratory of Biological Control of Universidade Estadual de Montes Claros (Unimontes). Five densities of C. capitata larvae (10, 20, 30, 40, and 50) were offered to parasitoid females that were at five different densities (1, 2, 5, 10, and 15). The larvae were exposed to the parasitoid females by means of "parasitism units" in adapted cages for 1 hour. Sex ratio, percentage of parasitism, and pupal mortality were evaluated. Both host larval density and female parasite density influenced parasitism, female progeny production, and pupal mortality. Higher female production was observed in the progeny in ratios of 1:1 and 2:1 (larvae/females). Ratios above 1:2 reduced the sex ratio, and ratios below 1:1 caused high pupal mortality rates. The females had higher parasitism activity when they were in groups dividing the same space. Equal ratios of Ceratitis capitata larvae and parasitoid females resulted in improved efficiency in progeny females.(AU)

Objetivou se neste estudo avaliar a proporção de larvas de Ceratitis capitata e fêmeas de Diachasmimorpha longicaudata que resulta no incremento do parasitismo e da produção de fêmeas na progênie. Foram utilizadas fêmeas de Diachasmimorpha longicaudata copuladas, com experiência em parasitar e oito dias de idade, e larvas de terceiro instar de C. capitata, provenientes da criação mantida no Laboratório de Controle Biológico da Universidade Estadual de Montes Claros (UNIMONTES). Cinco densidades de larvas de C. capitata foram oferecidas (10, 20, 30, 40 e 50) às fêmeas do parasitoide, em cinco densidades diferentes (1, 2, 5, 10 e 15). As larvas foram expostas às fêmeas do parasitoide por meio de "unidades de parasitismo", em gaiolas adaptadas, pelo tempo determinado de uma hora. Foram avaliadas as variáveis: razão sexual, porcentagem de parasitismo e mortalidade pupal. Tanto a densidade de larvas de C. capitata quanto a densidade de fêmeas do parasitoide influenciaram no parasitismo, na produção de fêmeas na progênie e na mortalidade pupal. Foi observada nas proporções 1:1 e 1:2 (larvas/fêmeas) maior produção de fêmeas na progênie. Proporções acima de 1:2 reduziram a razão sexual, e valores abaixo de 1:1 causaram altas porcentagens de mortalidade pupal. As fêmeas apresentaram maior atividade de parasitismo quando estavam em grupos dividindo o mesmo espaço. Proporções iguais de larvas de C. capitata e fêmeas do parasitoide resultaram em melhor eficiência na produção de fêmeas na progênie.(AU)

Parasitism of Diachasmimorpha longicaudata (Ashmead) on two fruit fly species / Parasitismo de Diachasmimorpha longicaudata (Ashmead) em duas espécies de moscas-das-frutas

The aim of the present study was to investigate the parasitism of two fruit fly species by different Diachasmimorpha longicaudata strains. Females of two parasitoid strains were reared on Ceratitis capitata or Anastrepha fraterculus that were conditioned in adapted containers. Individual parasitoids were offered 20 larvae for 1 h, using no-choice (20 C. capitata or 20 A. fraterculus) or free-choice (10 of each species) assays. Parasitism was verified by counting scars, and the pupae were classified as non-parasitized (no scars), parasitized (one scar), or superparasitized (multiple scars). Parasitism intensity was compared by evaluating the proportions of non-parasitized, parasitized, and superparasitized larvae. Parasitism intensity and scar frequency were analyzed as functions of host species and parasitoid strain, using chi-square tests. In the non-choice tests, females of both parasitoid strains parasitized the larvae, regardless of host species. However, when the parasitoids had a choice, they preferred to superparasitize A. fraterculus larvae, which are larger than C. capitata larvae. In addition, the female parasitoids parasitized most of the host larvae, regardless of parasitoid strain or host species. However, the frequency of non-parasitized pupae was higher when the offered host species was different from the one in which the parasitoid was reared, and the frequency of superparasitized pupae was higher when the offered host species was the same as the one in which the parasitoid was reared.(AU)

O objetivo deste trabalho foi avaliar o parasitismo de larvas de Tephritidae por duas linhagens de Diachasmimorpha ­longicaudata em duas espécies de mosca-das-frutas. Foram utilizadas fêmeas do parasitoide criadas sobre Ceratitis capitata ou Anastrepha fraterculus acondicionadas em gaiolas adaptadas. Para cada fêmea foram oferecidas 20 larvas durante 1 hora, em ensaio com chance de escolha (20 C. capitata ou 20 A. fraterculus) e sem chance de escolha (10 larvas de cada espécie). Após o parasitismo, o número de cicatrizes foi verificado e os pupários classificados como: não parasitados (ausência de cicatrizes), parasitados (presença de uma cicatriz) e superparasitados (duas ou mais cicatrizes). A intensidade de parasitismo foi avaliada por meio da proporção de larvas não parasitadas, parasitadas ou superparasitadas. As variáveis intensidade de parasitismo e frequência de cicatrizes em virtude do hospedeiro e da linhagem do parasitoide foram analisadas quanto à distribuição de frequência utilizando-se o teste qui-quadrado. No teste sem escolha, independentemente da espécie hospedeira, as fêmeas das duas linhagens parasitaram as larvas oferecidas e, quando tiveram escolha, preferiram superparasitar larvas de A. fraterculus, que são maiores que as de C. capitata. A frequência de pupários sem cicatriz foi maior quando o hospedeiro oferecido foi diferente daquele em que a fêmea foi criada. Independentemente da linhagem do parasitoide, as fêmeas parasitam a maioria das larvas hospedeiras das duas espécies, mas discriminam o hospedeiro, preferindo superparasitar a espécie na qual foi criada o hospedeiro. A. fraterculus foi o preferido para postura de fêmeas.(AU)

Aqueous extract of pequi fruit to control Spodoptera frugiperda in corn / Extrato aquoso de fruto de pequizeiro para o controle de Spodoptera frugiperda em milho

Pequi fruit peels contain steroids, triterpenes, flavonoids, tannins, and saponins, compounds that are potentially useful for integrated pest management. As such, the aim of this study was to evaluate the insecticidal activity of aqueous extracts of pequi fruit peels on Spodoptera frugiperda. Field-grown corn plants of the cultivar 'Al Alvaré' were sprayed with extract concentrations of 0.8%, 2.5%, 5%, and 10% (v/v) 40 and 47 days after germination. The pequi peels were chopped, oven dried (65°C for 72 hours), and ground in a grinding mill. The resulting powder was used to prepare a base-line extract (10%), and the other concentrations evaluated were prepared by diluting this extract. The intensity of the damage caused by S. frugiperda caterpillars was evaluated 43, 46, 50, and 53 days after germination, using a visual scoring scale. Application of the extract decreased the amount of damage caused by the caterpillars. The 5% extract concentration was the most effective, while the 10% extract concentration showed evidence of phytotoxicity after the second spraying. These results suggest that the pequi extract is toxic to the S. frugiperda caterpillars and can be used for the management of this pest.(AU)

Nas cascas dos frutos de pequi já foram identificados esteroides, triterpenos, flavonoides, taninos e saponinas, substâncias promissoras no manejo integrado de pragas. Com base nesta informação, objetivou-se com este trabalho avaliar a ação inseticida de extratos aquosos das cascas dos frutos de pequi a Spodoptera frugiperda. O ensaio foi realizado em campo, utilizando sementes de milho do cultivar 'AL Alvaré' que aos 40 e 47 dias após a germinação foram pulverizadas com concentrações dos extratos de 0,8%, 2,5%, 5% e 10% (v/v). Os extratos foram preparados a partir de cascas dos frutos de pequi que, após picadas, foram secas em estufa (65°C, por 72 horas) e moídas em moinho de facas. Com o pó foi preparado um extrato padrão (10,0%). As demais concentrações foram obtidas a partir deste extrato. Foram avaliadas a intensidade das injúrias causadas pelas lagartas de S. frugiperda em plantas com 43, 46, 50 e 53 dias, utilizando uma escala visual de notas. As pulverizações dos extratos reduziram o número de injúrias provocadas pelas lagartas. A concentração de 5% foi a mais eficiente nesta redução e a de 10% causou fitotoxicidade após a segunda pulverização. O extrato pequi é tóxico às lagartas de S. frugiperda e pode ser utilizado no manejo desta praga.(AU)

Bioatividade dos extratos aquosos de plantas às larvas da mosca-das-frutas, Ceratitis capitata (Wied. ) / Bioactivity of aqueous extracts of plants to the fruit fly larvae, Ceratitis capitata (Wied. )

O objetivo deste trabalho foi avaliar a toxicidade dos extratos aquosos de plantas às larvas recém-eclodidas de Ceratitis capitata. Folhas de algodão-de-seda (Calotropis procera), citronela (Cymbopogon nardus), juazeiro (Ziziphus joazeiro), pinha (Annona squamosa),pinhão-manso (Jatropha curcas), noni (Morinda citrifolia) e tingui (Magoniapubescens) foram coletadas, secas e moídas em moinho de facas até a obtenção de um pó. Tais pós foram adiciona dos em água destilada para a preparação dos extratos aquosos (10%, p/v). As suspensões contendo os compostos hidrossolúveis foram filtradas, a fim de se conseguir os extratos que foram adicionados à dieta artificial das larvas da mosca. À dieta controle, adicionou-se somente água destilada. Os ensaios foram realizados em DIC, com quatro tratamentos e um controle. Todos os tratamentos foram constituídos por 10 repetições, cada uma com 10 larvas recém-eclodidas de C. capitata. Foram avaliadas a mortalidade larval e a eficiência de controle (E%) dos extratos aquosos às larvas. Os extratos de juazeiro, tingui e pinhão-manso são os mais tóxicos e eficientes no controle das larvas de C. capitata, causando elevadas mortalidades.(AU)

The objective of this study was to evaluate the toxicity of aqueous plant extracts to neonate larvae of Ceratitis capitata. Silk cotton (Calotropis procera), citronella grass (Cymbopogon nardus), joazeiro (Ziziphus joazeiro),sugar apple (Annona squamosa), jatropha (Jatropha curcas), noni (Morinda citrifolia) and tingui (Magonia pubescens) were collected, dried, and milled in a knife mill in order to obtain a powder. These powders were added in distilled water to prepare aqueous extracts (10%, w/v). The suspension containing the hydrosoluble compounds was filtered to get the extracts, which were added to the artificial diet of fruit fly larvae. Only distilled water was added in the control diet. Assays were carried out in DIC, with four treatments (aqueous extracts) and one control. All treatments consisted of 10 repetitions, each containing 10 newly hatched larvae ofC. capitata. Larval mortality and control efficiency (E%) of aqueous extracts to the larvae were evaluated. The joazeiro, tingui and jatropha extracts are the most toxic and effective in controlling larvae of C. capitata, causing high mortality.(AU)