Résumé
ABSTRACT Chrysoperla externa (Hagen) and Hippodamia convergens (Guérin-Meneville) are voracious generalist predators, and important aphid control agents. In an environment containing a complex of species, the occurrence of intraguild interactions can interfere in the predator behavior and consumption. The aim of this work was to know the number of nymphs of Rhodobium porosum (Sanderson) and Macrosiphum rosae (Linnaeus) consumed by larvae of C. externa and H. convergens, and the interaction between these predators when confined together. First, second and third instar nymphs of R. porosum and M. rosae were provided in Petri dishes containing rose leaflets and second instar larvae of the predators. Intraguild interaction was studied in Petri dishes containing first instar nymphs of both aphid species and a second instar larva of C. externa plus one of H. convergens. A third treatment consisted of dishes containing a second instar larva of both predators maintained in the absence of prey. The evaluations took place throughout the entire instar of the predators. C. externa consumed a greater number of R. porosum nymphs and H. convergens a greater number of M. rosae nymphs. For both species of prey, the highest consumption was verified on the last day of evaluation. There was a positive interaction when the predator's larvae were confined in the presence of aphid nymphs, with no mortality observed for any of them. In the absence of prey, there was 70% mortality of H. convergens larvae due to intraguild predation.
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Resumen Se presenta una revisión de los ejemplares de Coccinellini micofagos procedentes de varias provincias del departamento del Cusco, en el sur oriente de Perú. Este grupo presenta actualmente nueve especies en el país, dentro de los géneros Oxytella Weise 1902, y Psyllobora Chevrolat 1836. En el material examinado se reporta la ocurrencia de cinco de ellas: Oxytella longula Weise, Psyllobora marshalli Crotch, abancayana Almeida, P. constantini González, Perla & Almeida, y P. hybrida (Mulsant); además de otras tres especies, aún no identificadas, dentro del género Psyllobora. Para cada especie se presenta una diagnosis, fotografías y microfotografías de habito y estructuras genitales, e información sobre su distribución en Cusco.
Abstract In this work, we presented a review of the specimens of mycophagous Coccinellini from various provinces of the Cusco Department, south east of Peru. This group currently has nine species in the country, within the genera Oxytella Weise 1902, and Psyllobora Chevrolat 1836. In the material examined the occurrence of five of them is reported: Oxytella longula Weise, Psyllobora marshalli Crotch, P. abancayana Almeida, P. constantini González, Perla & Almeida, and P. hybrida (Mulsant); in addition to three other species, not yet identified, within the genus Psyllobora. For each species a diagnosis, photographs and photomicrographs of habit and genital structures, and information on their distribution in Cusco are presented.
Résumé
Plans for an agro-ecological system for agricultural production must consider vegetal diversification in agricultural properties because, among other advantages, it can help the biological control of pests when it focuses on such an end. Predator ladybeetles (Coleoptera: Coccinellidae) can be found in different environments; they play an important role in biological control. The aims of the present study were to feature ladybeetle populations through faunistic analysis and determine their fluctuations in an agro-ecological system comprising seven sub-systems subjected to different cultivation systems in Seropédica County, RJ. The experiment was conducted from December/2018 to December/2019 at Módulo de Cultivo Orgânico Intensivo de Hortaliças (MCOIH), which is located at Sistema Integrado de Produção Agroecológica (SIPA). In total, 1,231 adult ladybeetles were captured, distributed into 13 species, 3 genera and 2 tribes of Coccinellidae, which resulted in S (taxon richness) = 19, Shannon-Wiener diversity index (H') = 0.65 (at 0 to 1 scale) and Margalef diversity index (α) = 2.53 (values lower than 2.0 represent low diversity sites). Equitability was low (E = 0.22), since one of the ladybeetle species has prevailed: Cycloneda sanguinea (most frequent, dominating and constant) in MCOIH, as well as in each of the sub-systems. However, the simplest sub-systems installed for vegetable production (monoculture gardens) were not favorable for ladybeetle diversity, whereas sub-systems installed for polyculture of leafy vegetables recorded the greatest taxa diversity of ladybeetles, including species that predate in aphids that attack vegetables [Coleomegilla maculata, Coleomegilla quadrifasciata, Cycloneda sanguinea, Eriopis connexa, Harmonia axyridis, Hippodamia convergens and Hyperaspis (Hyperaspis) festiva]. The sub-system comprising gliricidia was used to produce fertilization biomass and favored the predominance of C. sanguinea in comparison to the other ladybeetle species in MCOIH. Spring was the season mostly favoring the occurrence of C. sanguinea and H. convergens adults; which were dominant species in ladybeetle assemblage in MCOIH; however, C. sanguinea was constant and H. convergens was accessory.
Sujets)
Coléoptères , Biodiversité , Agriculture Durable , Lutte biologique contre les nuisiblesRésumé
Resumen Se cita por primera vez el género Neoparasitylenchus Nickle, 1967 (Tylenchida, Allantonematidae), parásito de Harmonia axyridis (Pallas, 1773) (Coleoptera, Coccinellidae) para Argentina. Se describe la especie nueva Neoparasitylenchus platense sp. n. que se caracteriza por tener en las formas de vida libre la región labial rodeada de una estructura plana, estilete delgado, levemente curvado, apéndice caudal redondeado, hembras con cuerpo marrón claro, estilete no hundido en el cuerpo y no prominente, vulva y ano subterminal, apéndice caudal redondeado, con una proyección en forma de clavija, ovíparos. Los machos con un estilete y un esófago parcialmente degenerados, espículas filiformes con base ensanchada, gubernaculum corto, bursa leptodera.
Abstract Presence of the genus Neoparasitylenchus Nickle, 1967 (Tylenchida, Allantonematidae), parasitizing Harmonia axyridis (Pallas, 1773) (Coleoptera, Coccinellidae) in Argentina. We describe a new species Neoparasitylenchus platense sp. n., which is characterized by having the free living stages lip region flatly rounded, spear slender, faintly knobbed, tail rounded, females with light brown body, stylet not sunken into body, and not prominent, subterminal vulva and anus, obtusely rounded tail end, with a peg-like projection, oviparous, and the males with a little stylet and partially degenerate oesophagus, spicules filiform with widened base, short gubernaculum, leptodera bursa.
Résumé
Se cita y describe por primera vez para Argentina Parasitylenchus pseusobifurcatus sp.n. (Tylenchida, Allantonematidae), parásito de adultos de Harmonia axyridis (Pallas, 1773) (Coleopera, Coccinellidae). Esta nueva especie está muy cercana a P. bifurcatus Poinar Jr. y Steenberg, 2012, por la característica de tener todas las hembras vermiformes y los machos inmaduros la punta del apéndice caudal bifurcada, pero se diferencian entre otros por el tamaño del gubernáculo. Se describe su fórmula cariotípica.
Parasitylenchus pseusobifurcatus sp.n. (Tylenchida, Allantonematidae) is described for the first time for Argentina as a parasite of adults of Harmonia axyridis (Pallas, 1773) (Coleopera, Coccinellidae). The new species is closed to P. bifurcatus Poinar Jr. & Steenberg, 2012, by the characteristic of having the tail tip of all vermiform females and immature males bifurcated, but they differ by the size of the gubernaculum. Its karyotype formula is described.
Résumé
For the first time in Argentina, we report that in Harmonia axyridis Pallas, 1773, and Cycloneda sanguinea (Linnaeus, 1763) (Coleoptera, Coccinellidae) parasitizing by nematodes which belong to the family of Allantonematidae (Nematoda, Tylenchida). The genera are Metaparasitylenchus Wachek, 1955 (Nickle, 1967), Sulphuretylenchus Rühm, 1956 (Nickle, 1967) and Contortylenchus Rühm, 1956. They will be described and photographied afterwards.
Se cita por primera vez para la Argentina nemátodos parásitos de Harmonia axyridis Pallas, 1773, y Cycloneda sanguinea (Linnaeus, 1763) (Coleoptera, Coccinellidae), estos nemátodos pertenecen a la familia de Allantonematidae (Nematoda, Tylenchida). Los géneros hallados son Metaparasitylenchus Wachek, 1955 (Nickle, 1967), Sulphuretylenchus Rühm, 1956 (Nickle, 1967) y Contortylenchus Rühm, 1956. Se describen y fotografían.
Résumé
BACKGROUND: Changed temperature not only threaten agricultural production, but they also affect individual biological behavior, population and community of many insects, and consequently reduce the stability of our ecosystem. Insect's ability to respond to temperature stress evolved through a complex adaptive process, thus resulting in varied temperature tolerance among different insects. Both high and low extreme temperatures are detrimental to insect development since they constitute an important abiotic stress capable of inducing abnormal biological responses. Many studies on heat or cold tolerance of ladybirds have focused on measurements of physiological and biochemical indexes such as supercooling point, higher/lower lethal temperatures, survival rate, dry body weight, water content, and developmental duration. And studies of the molecular mechanisms of ladybird responses to heat or cold stress have focused on single genes, such as those encoding heat shock proteins, but has not been analyzed by transcriptome profiling. RESULTS: In this study, we report the use of Digital Gene Expression (DGE) tag profiling to gain insight into transcriptional events associated with heat- and cold-stress in C. montrouzieri. About 6 million tags (49 bp in length) were sequenced in a heat stress group, a cold stress group and a negative control group. We obtained 687 and 573 genes that showed significantly altered expression levels following heat and cold shock treatments, respectively. Analysis of the global gene expression pattern suggested that 42 enzyme-encoding genes mapped to many Gene Ontology terms are associated with insect's response to heat- and cold-stress. CONCLUSIONS: These results provide a global assessment of genes and molecular mechanisms involved in heat and cold tolerance.