Reproductive potential of Spodoptera eridania (Stoll) (Lepidoptera: Noctuidae) in the laboratory: effect of multiple couples and the size

Abstract This study aimed to evaluate the effect of keeping three couples in the same cage, and the size of adults emerged from small, medium-sized and large pupae (278.67 mg; 333.20 mg and 381.58 mg, respectively), on the reproductive potential of S. eridania (Stoll, 1782) adults, under controlled conditions (25 ± 1 °C, 70% RH and 14 hour photophase). We evaluated the survival, number of copulations, fecundity and fertility of the adult females. The survival of females from these different pupal sizes did not differ statistically, but the survival of males from large pupae was statistically shorter than from small pupae. Fecundity differed significantly and correlated positively with size. The number of effective copulations (espematophores) and fertility did not vary significantly with pupal size. Our results emphasize the importance of indicating the number of copulations and the size of the insects when reproductive parameters are compared.(AU)

Resumo Este estudo objetivou avaliar o efeito de confinar três casais em cada gaiola e o tamanho de adultos emergidos de pupas pequenas, medias e grandes (278,67 mg, 333,20 mg e 381,58 mg, respectivamente), sobre o potencial reprodutivo de S. eridania (Stoll, 1782), em condições controladas (25 ± 1 °C, 70% UR e 14 horas de fotofase). Avaliou-se a sobrevivência, o número de cópulas, fecundidade e fertilidade dos adultos. A sobrevivência não diferiu significativamente entre fêmeas provenientes de pupas de diferentes tamanhos, mas os machos oriundos de pupas grandes tiveram sobrevivência significativamente menor que os demais tamanhos. A fecundidade diferiu significativamente e correlacionou-se positivamente com o tamanho. O número de cópulas (espematóforos) e a fertilidade não variaram em função do peso pupal. Os resultados enfatizam a importância de indicar o número de cópulas e o tamanho dos insetos estudados para que comparações entre os parâmetros reprodutivos possam ser efetuadas.(AU)

Embryogenesis of Heliconius erato (Lepidoptera, Nymphalidae): a contribution to the anatomical development of an evo-devo model organism.

This study reports on the embryogenesis of Heliconius erato phyllis between blastoderm formation and the prehatching larval stage. Syncytial blastoderm formation occurred approximately 2 h after egg laying (AEL) and at about 4 h, the cellular blastoderm was formed. The germ band arose from the entire length of the blastoderm, and rapidly became compacted occupying approximately two-thirds of the egg length. At about 7 h AEL, protocephalon and protocorm differentiation occurred. Continued proliferation of the germ band was followed by penetration into the yolk mass, forming a C-shaped embryo at about 10 h. Approximately 12 h AEL, the gnathal, thoracic and abdominal segments became visible. The primordium of the mouthparts and thoracic legs formed as paired evaginations, while the prolegs formed as paired lobes. At about 30 h, the embryo reversed dorsoventrally. Approximately 32 h AEL, the protocephalon and gnathal segments fused, shifting the relative position of the rudimentary appendages in this region. At about 52 h, the embryo was U-shaped in lateral view and at approximately 56 h, the bristles began evagination from the larval cuticle. Larvae hatched at about 72 h. We found that H. erato phyllis followed an embryonic pattern consistent with long-germ embryogenesis. Thus, we believe that H. erato phyllis should be classified as a long-germ lepidopteran. The study of H. erato phyllis embryogenesis provided a structural glimpse into the morphogenetic events that occur in the Heliconius egg period. This study could help future molecular approaches to understanding the evolution of Heliconius development.

Intensidade de ataque a lagartas artificiais em diferentes formações vegetais do Cerrado / Intensity of attack on artificial caterpillars in different Cerrado vegetation types, Brazil

A complexidade estrutural do hábitat influencia os padrões de diversidade das espécies e também as interações ecológicas, como a predação. O objetivo deste trabalho foi avaliar a intensidade de ataque de um modelo de inseto herbívoro (lagartas artificiais) em formações vegetais de Cerrado com diferentes níveis de complexidade estrutural (campo sujo, campo cerrado, cerrado sensu stricto e mata estacional semidecídua). As unidades amostrais consistiram de 40 parcelas de 10 x 10m distribuídas entre as quatro formações vegetais citadas acima. Em cada parcela, foram fixadas sobre a vegetação, a cerca de 1m de altura, 30 lagartas artificiais feitas de massa de modelar não tóxica com tamanho, forma e coloração semelhantes. O número de lagartas com marcas de ataque foi mensurado após quatro dias de exposição. A diferença da intensidade de ataque entre as formações vegetais foi analisada através de uma Anova seguida do teste a posteriori de Tukey. A intensidade de ataque média foi significativamente maior no campo sujo (formação vegetal estruturalmente mais simples do estudo) do que nas demais formações vegetais (F3,36-7,85, p=0,0003). Em virtude de ficarem mais expostas tanto visual quanto quimicamente em ambientes estruturalmente mais simples (com menor riqueza e densidade de plantas lenhosas), as lagartas artificiais podem ser mais facilmente localizadas e atacadas por predadores e parasitoides.

The structural complexity of the habitat influences the patterns of species diversity and the ecological interactions, such as predation. The aim of this study was to evaluate the intensity of attackon a model of herbivore insect (artificial caterpillars) in the Cerrado vegetation types with different levels of structural complexity (campo sujo, campo cerrado, cerrado sensu stricto and semideciduous forest). The sample units consisted of 40 plots of 10x10m distributed among the four types of vegetation mentioned above. In each plot, 30 artificial caterpillars made of non-toxic clay with similar sizes, shapes and colors were placed on vegetation at about 1m high. The number of artificial caterpillars with attack marks was measured after four days of exposure. The difference in the intensity of attack among the types of vegetation was analyzed using Anova followed by Tukey's post-hoc test. The mean intensity of attack was significantly higher in the campo sujo (structurally simplest plant formation of the study) than in other types of vegetation (F336-7.85, p=0.0003). Due to being more exposed both visually and chemically in the structurally simpler habitat (less richness and density of woody plants) artificial caterpillars can be more easily located and attacked by predators and parasitoids.

Efeito da idade do parasitoide e do hospedeiro na reprodução de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) em ovos de Bonagota salubricola (Meyrick) (Lepidoptera: Tortricidae) / Effect of the parasitoid and host age on the reproduction of Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) in eggs of Bonagota salubricola (Meyrick) (Lepidoptera: Tortricidae)

Foram avaliadas características biológicas de fêmeas de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) linhagem bonagota com três idades sobre ovos deBonagota salubricola (Meyrick) (Lepidoptera: Tortricidae) com cinco períodos de desenvolvimento embrionário. Ovos de B. salubricola com 0-24, 24-48, 48-72, 72-96, 96-120 horas de desenvolvimento embrionário foram oferecidos ao parasitismo por fêmeas de T. pretiosum com 0-24, 24-48 e 48-72 horas de idade, por 24 horas à 25 ± 1º C, 70 ± 10% de umidade relativa e 14 horas de fotofase. Fêmeas do parasitoide com 0-24 horas de vida apresentaram melhores taxas de parasitismo em ovos do hospedeiro com 24-48 horas de desenvolvimento embrionário. Fêmeas com 24-48 e 48-72 horas de vida apresentaram preferência por ovos com 0-24 horas de desenvolvimento embrionário. O percentual de emergência variou entre 20,0 e 60,0%, a razão sexual entre 0,56 e 0,85 e o número de parasitoides/ovo foi superior a um, sem diferença significativa. O ideal para programas de controle biológico de B. salubricola é utilizar o parasitoide na idade de 0-24 horas.

Biological characteristics ofTrichogramma pretiosumRiley (Hymenoptera: Trichogrammatidae) strain bonagota with three ages on eggs of Bonagota salubricola (Meyrick) (Lepidoptera: Tortricidae) at five embryonic developmental stages was studied under laboratory conditions (25 ± 1º C, 70 ± 10% of relative humidity and 14 hours of photophase). B. salubricola eggs with 0­24, 24­48, 48­72, 72­96, 96­120 hours of embryonic developmental stages were offered to T. pretiosum during 24 hours using parasitoid females with 0­24, 24­48 and 48­72 life hours. Parasitoid females with age of 0­ 24 hours showed a higher parasitism rate in eggs of B. salubricola with 24­48 hours of embryonic development. Females with age of 24­48 and 48­72 hours, showed a preference for eggs with 0­ 24 hours of embryonic development. Adult emergence and sex ratio ranged from 20.0 to 60.0% and from 0.56 to 0.85 respectively. The number of parasitoids/egg was always more than one, ranging from 1.03 to 1.14. The ideal for a biological control program of B. salubricola using T. pretiosum strain bonagota is to use parasitoids with a maximum of 24 hours of age.

Descripción de la larva de último instar y de la pupa de Cryptophlebia cortesi Clarke (Lepidoptera: Tortricidae) / Description of the last instar larva and pupa of Cryptophlebia cortesi Clarke (Lepidoptera: Tortricidae)

Se presenta una descripción de la larva de último instar y de la pupa de Cryptophlebia cortesi Clarke, sobre la base de ejemplares colectados en el valle de Chaca, Primera Región, Chile, asociados a yaro, Acacia macracantha Bonpl & Humb ex Willd. (Fabaceae).

A description of the last instar larva and pupa of Cryptophlebia cortesi Clarke, based on specimens collected on yaro, Acacia macracantha Bonpl & Humb ex Willd. (Fabaceae), in the Chaca valley, Primera Región, Chile, is presented.

Mortality staging of dominant lethals induced in the F1 generation of the sugarcane borer; Diatraea saccharalis (f.).

Comparative egg maturation was observed between fertile eggs laid by unirradiated females, by unirradiated females mated with irradiated males, by irradiated females mated with normal males, and by virgin unirradiated females. Haploid eggs turn yellow and dry by the fifth day. Eggs from irradiated parents develop more slowly than normal eggs. Most embryos from parents irradiated as P generation adults at 16.8 kilorads for males and 12.0 kR for females die early in embryonic development. A description of egg development is included.