Leonardo Rodrigues Barbosa

Eficiência de Chrysoperla externa (Hagen, 1861)(Neuroptera: Chrysopidae) no controle de Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae) em pimentão (Capsicum annum L.)

Avaliou-se a eficiencia de larvas de primeiro instar de Chrysoperla externa no controle Myzus persicae em pimentao, em experimentos realizados em câmara e sala climatizadas a 25 ± 1oC, UR de 70 ± 10% e fotofase de 12 horas. Larvas de C. externa recem-eclodidas foram liberadas em discos foliares, contendo 5; 10 ou 20 ninfas do afideo, acondicionados em placas de Petri. Em um segundo experimento, larvas do predador foram liberadas nas proporcoes 1:5, 1:10 e 1:20, em plantas inoculadas com 60; 100 e 140 ninfas do pulgao. O potencial predatorio de C. externa nos discos foliares foi influenciado pela densidade inicial do pulgao. A eficiencia do predador nas densidades de 5; 10 e 20 pulgoes foi de 100%; 96,7% e 79,3%, respectivamente. A eficiencia das larvas em eliminar as populacoes do pulgao nas plantas de pimentao variou em funcao do tempo. Na proporcao 1:5, a eliminacao das ninfas ocorreu entre um e dois dias apos a liberacao do predador, enquanto nas proporcoes 1:10 e 1:20 o periodo de quatro dias nao foi suficiente para que os pulgoes fossem eliminados. As larvas de C. externa quando liberadas nas tres proporcoes promoveram reducoes na populacao de M. persicae, se comparada a testemunha. No entanto, nas proporcoes 1:5 e 1:10 o predador se mostrou mais eficiente.

Meiotic chromosomes and nucleolar behavior in testicular cells of the grassland spittlebugs Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana (Hemiptera, Auchenorrhyncha)

Spittlebugs annually infest pastures and cause severe damage, representing a serious problem for the tropical American beef cattle industry. Spittlebugs are an important biotic constraint to forage production and there is a lack of cytogenetic data for this group of insects. For these reasons, we conducted this work, in which the spermatogenesis and nucleolar behavior of Deois flavopicta, Mahanarva fimbriolata and Notozulia entreriana were studied. The males possessed testes in the shape of a “bunch of grapes”; a variable number of testicular lobes per individual and polyploid nuclei composed of several heteropycnotic bodies. A heteropycnotic area was located in the periphery of the nucleus (prophase I); the chiasmata were terminal or interstitial; metaphases I were circular or linear and anaphase showed late migration of the sex chromosome. The chromosome complement had 2n = 19, except for N. entreriana (2n = 15); the spermatids were round with heteropycnotic material in the center and elongated with conspicuos chromatin. The analysis of testes after silver nitrate staining showed polyploid nuclei with three large and three smaller nucleolar bodies. Early prophase cells had an intensely stained nucleolar body located close to the chromatin and another less evident body located away from the chromatin. The nucleolar bodies disintegrated during diplotene. Silver staining occurred in two autosomes, in terminal and subterminal locations, the latter probably corresponding to the nucleolus organizer regions (NORs). The spermatids were round with a round nucleolar body and silver staining was observed in the medial and posterior region of the elongated part of the spermatid head.

Functional compartmentalisation of nutrients and phenolics in the tissues of galls induced by Leptocybe invasa (Hymenoptera: Eulophidae) on Eucalyptus camaldulensis (Myrtaceae)

Galling herbivores induce structural and chemical alterations in their host plants tissues. These insects have been the focus of little study in the case of Australian taxa. Leptocybe invasa, a native Australian galling hymenopteran associated with Eucalyptus species, causes economic damage to plantation eucalypts in many countries around the world. Leptocybe invasa oviposits in the midribs and petioles of expanding leaves thereby intercepting photosynthates and impairing normal expansion. We analysed the ultrastructural and chemical cellular changes in L. invasa galls on Eucalyptus camaldulensis (probably subspecies camaldulensis) to diagnose how the insect manipulates plant cells and tissues and the significance of these alterations for insect nutrition and protection. Galling stimuli induce the formation of two functionally compartmentalised types of tissue. Phenolic plant secondary metabolites and anthocyanins (plant pigments) accumulate in the outer compartment, while primary metabolites accumulate in the inner compartment. The nutritive cells (inner compartment) accumulate protein and lipids that provide food for the larvae. Total polyphenol concentrations did not differ significantly between outer and inner compartments. Nevertheless, the concentrations of quercetin and kaempferol derivatives were higher in the outer compartment than in the inner compartment. These differences could be related to the protection of plant tissues against ultraviolet rays and the maintenance of redox homeostasis. There were higher ratios of hexahydroxydiphenoyl‐containing hydrolysable tannins rather than galloyl‐containing hydrolysable tannins in the inner compartment. This shift in the oxidative capacity of the polyphenols in the inner compartment could represent a defensive plant response to the larvae.

Longevity of Cleruchoides noackae (Hymenoptera: Mymaridae), an egg parasitoid of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae), with various honey concentrations and at several temperatures

Abstract Thaumastocoris peregrinus Carpintero and Dellapé (Hemiptera: Thaumastocoridae), damages eucalyptus plants by sucking their sap. This pest can be controlled by releases of the egg parasitoid Cleruchoides noackae Lin and Huber (Hymenoptera: Mymaridae). Increasing the survival of this parasitoid is critically important for its mass rearing in order to release large numbers in integrated programs to manage T. peregrinus. The aim of this study was to evaluate the longevity of C. noackae adults fed various honey concentrations at 6 constant temperatures. The longevity of C. noackae was studied by keeping adults in a 1st experiment with 100, 50, or 10% honey solution, with distilled water, or without water and food in climate-controlled chambers at 25 ± 2 °C, 70 ± 10% RH, and a 12:12 h L:D photoperiod and—in a 2nd experiment—with 100% honey at constant temperatures of 15, 18, 21, 25, 28, or 31 °C in a climatic chamber at 70 ± 10% RH and a 12:12 h L:D photoperiod. Each adult parasitoid was held individually in a glass tube capped with plastic wrap under the conditions described, and the survival of adults was recorded daily. The longevity of C. noackae varied with food and temperature such that longevity was enhanced by all honey concentrations and temperatures of 25 °C and below. When fed honey, this parasitoid lived 2 to 3 fold longer when kept at 15, 18, 21, and 25 °C than at 28 and 31 °C. Thus, the parasitoid C. noackae should be mass reared with honey at temperatures from 15 to 25 °C for subsequent distribution of parasitoid adults in eucalyptus plantations for suppressing T. peregrinus.

Selitrichodes neseri (Hymenoptera: Eulophidae) Recovered from Leptocybe invasa (Hymenoptera: Eulophidae) Galls After Initial Release on Eucalyptus (Myrtaceae) in Brazil, and Data on Its Biology

Abstract Blue gum chalcid, Leptocybe invasa Fisher & La Salle (Hymenoptera: Eulophidae), causes galling damage to Eucalyptus species (Myrtaceae) in various regions of the world, but has been controlled effectively by its primary parasitoid, Selitrichodes neseri Kelly & La Salle (Hymenoptera: Eulophidae). The objectives of this study were to evaluate the recovery of S. neseri after its initial release on Eucalyptus plants in Brazil and to provide data on its biology. Selitrichodes neseri was imported from South Africa to Brazil for the biological control of L. invasa, in Mar 2015, and recovered from Aug 2015 to Dec 2016. Successful recovery of this parasitoid shows its potential to become established in the field. Seedlings of 2 hybrids obtained from crosses between rose gum Eucalyptus grandis W. Hill. ex Maiden and flooded gum Eucalyptus urophylla S. T. Blake and between Eucalyptus sp. and (river red gum Eucalyptus camaldulensis Dehnh. × E. grandis) showed potential as hosts for culture of S. neseri on L. invasa in the laboratory because up until the adult parasitoid emergence these seedlings did not wilt. When reared at 25.1 to 26.0 °C, the total number of parasitoids and the proportion of male parasitoids were highest, relative to hosts reared at 26.1 to 27.0 °C. Peak emergence of S. neseri occurred 28 d after parasitism.

Tabelas de esperança de vida e fertilidade de Myzus persicae sobre pimentão em laboratório e casa de vegetação

Estudos de tabelas de vida de insetos-praga em diferentes temperaturas auxiliam na compreensao da dinâmica populacional desses organismos. Objetivou-se calcular tabelas de esperanca de vida e de fertilidade de Myzus persicae criado em pimentao Capsicum annuum, em diferentes condicoes termicas. O estudo foi realizado em câmaras climatizadas, nas temperaturas de 15, 20, 25 e 30 oC, UR de 70±10% e fotofase de 12 horas, e em casa de vegetacao em temperaturas oscilantes, com media de 24,9 oC e UR de 68,1%. A longevidade maxima de adultos de M. persicae foi maior a 15 oC (45 dias) e diminuiu a 20 oC (39 dias), 25 oC (27 dias), 30 oC (24 dias) e, em casa de vegetacao a 24,9 oC foi de 29,5 dias. A esperanca de vida (ex) no primeiro dia de observacao foi de 43,76; 35,39; 21,44; 17,67 e 17,03 dias, para as ninfas mantidas a 15, 20, 25, 30 e 24,9 oC respectivamente, tendo a partir dai uma queda acentuada ate o fim das observacoes. Os parâmetros de tabelas de vida e de fertilidade evidenciaram que a temperatura de 25 oC proporcionou a melhor condicao termica para o crescimento populacional de M. persicae, com maior capacidade de aumentar em numero (rm = 0,31) e menor tempo necessario para a populacao duplicar (TD=2,22 dias). Em casa de vegetacao a oscilacao termica afetou o crescimento populacional, proporcionando menor valor de rm (0,28) e maior TD (2,47 dias), comparados aqueles mantidos a temperatura constante equivalente.

Biological aspects of the immature stages of Ceraeochrysa everes (Banks) (Neuroptera: Chrysopidae)

A knowledge of the behavior and biological aspects of natural enemies is extremely important for the establishment of biological control programs. Biological aspects of the larvae, pre-pupae and pupae of the predator Ceraeochrysa everes (Banks) were studied. Larvae of the adult F1 generation were reared in the laboratory (25 ± 2°C, 65 ± 10 % RH and 14h photophase) on eggs of the Angoumois grain moth Sitotroga cerealella (Olivier). The duration and viability of the embryonic period, development of the immature stages and egg-adult period were evaluated. The mean embryonic period was 5.0 days, while the mean durations of the first, second and third instars were: 5.1 ± 0.03; 4.3 ± 0.05 and 4.5 ± 0.05 days, respectively, with viability exceeding 90%. Duration of the larval, pre-pupal and pupal stages averaged 13.9 ± 0.07; 5.7 ± 0.07 and 9.6 ± 0.12 days, respectively. Duration of the biological cycle was 34 ± 0.11 days on average. S. cerealella eggs were not suitable for rearing C. everes under laboratory conditions because they affected predator development.

Eficiência de Beauveria bassiana Vuill. e Isaria sp. para o controle de Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae).

The search for information to control Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae) in Eucalyptus , focus on the use of biological control techniques, including the use of entomopathogenic fungi. The objective of this study was evaluated the pathogenicity of Beauveria bassiana and Isaria sp. on Thaumastocoris peregrinus, under laboratory conditions. To do so, we tested four isolates of Beauveria bassiana and one isolate of Isaria sp. concentration of 1.0 × 10 8 conidia mL -1 . The solution was applied on leaves of Eucalyptus camaldulensis , provided as food for the insect substrates, and maintained in glass bottles sealed with plastic film in a climatic chamber (26 ± 2 ° C, 14 h photoperiod and U.R. 70 ± 10%). Four replicates were performed (bottles) for isolated with 13 adult insects per bottle. Each bottle received 13 adult insects. Evaluations were performed until the fifth day after application. The dead insects were placed in humid chamber for confirmation of death by pathogen. All isolates were pathogenic to Thaumastocoris peregrinus . The confirmed mortality ranged between 37% and 80.1% for Beauveria bassiana , and was 87% for Isaria sp. after 10 days of application. The highest mean percentage of daily mortality (39.9%) occurred on the fourth day after contact with the substrate insect spray. The isolates of Beauveria bassiana and Isaria sp. evaluated presented potential to control Thaumastocoris peregrinus under laboratory conditions.

Essential oils cause detrimental effects on biological parameters of Trichogramma galloi immatures

Essential oils from botanical extracts used for insect pest control should be both effective and have low impact on natural enemies. The objective was to evaluate the effects of ten essential oils on the biological and reproductive parameters in two Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae) generations. The emergence F1 generation of T. galloi was reduced by more than 30% with Allium sativum, Carapa guianensis, Citrus sinensis, Neem and Syzygium aromaticum. Zingiber officinale reduced the T. galloi emergence of the F1 and F2 generations by between 30 and 99%. The longevity of the F1 generation was reduced by more than 50% with Z. officinale at the pre-pupae and pupae stages. All oils reduced the parasitism rate of the F1 generation in the egg-larva and pre-pupa stages. Allium sativum, C. guianensis and C. sinensis, Neem and Origanum vulgare reduced parasitism by between 30 and 79%. Zingiber officinale was slightly and moderately harmful to the F1 and F2 generations, respectively, for the T. galloi parasitism. The sex ratio of the two T. galloi generations was not affected by the essential oils. The low side effects of the oils on the F2 generation, except for Z. officinale (the most harmful oil), suggest that T. galloi developed some post-transgenerational tolerance/resistance mechanisms to these oils and/or their components. The A. sativum, C. guianensis, C. sinensis, Neem, O. vulgare, S. aromaticum and Z. officinale oils were not selective for T. galloi. Mentha piperita, Piper nigrum and Thymus vulgaris essential oils can be included in integrated pest management programs for this parasitoid.

Oviposition Behaviour of Cleruchoides noackae (Hymenoptera: Mymaridae) in the Laboratory

Thaumastocoris peregrinus has become a major pest in eucalyptus. The most promising control method is the use of the parasitoid, Cleruchoides noackae, but little is known about its biology. Thus, the aim of this study was to investigate the oviposition behaviour of C. noackae in T. peregrinus eggs laid on strips of paper towel in the laboratory. 12 copulated females were placed in a plastic petri dish containing five T. peregrinus eggs and their behaviour was observed for 30 min/female. Several behavioural events were performed: searching for the host, host evaluation, insertion of the ovipositor, internal recognition and oviposition. Time elapsed between the insertion of the ovipositor and its removal varied from two to ten minutes. Learning more about C. noackae biology is very important to understand the dynamics between the parasitoid and its host, aiming at its biological control.