Interspecific insect relationships on Terminalia argentea (Myrtales: Combretaceae) trees in the Cerrado biome.

Terminalia argentea Mart. (Combretaceae), native to Brazil, is used in habitat restoration programs. Arthropods are bioindicators because their populations reflect changes in the environment. We evaluated the recovery of a degraded area by using ecological indices and analyzing arthropod interactions on T. argentea plants. The richness and diversity of sap-sucking Hemiptera and the abundance of tending ants and Sternorrhyncha predators increased with the number of T. argentea leaves. The correlation of the abundance of tending ants and Sternorrhyncha predators was positive with that of the sap-sucking Hemiptera, and the abundance of Sternorrhyncha predators was negative with that of tending ants and sap-sucking Hemiptera. The positive correlation between the abundance, richness, and diversity of insect groups and numbers of T. argentea leaves is an example of the bottom-up regulation mechanism, with the population dynamics of the lower trophic levels dictating those of higher trophic levels. The contribution of T. argentea, a host plant of many arthropods, to the recovery of ecological relationships between organisms in degraded ecosystems is important.

Morphology and Morphometry of the Reproductive Tract of the Cotton Boll Weevil after Prolonged Feeding on Alternative Diets.

Anthonomus grandis Boheman (Coleoptera: Curculionidae) survives on alternative diets; however, this induces reproductive diapause. The objective was to evaluate the morphology and morphometry of the reproductive tract of this weevil after feeding on alternative diets. The experimental design was completely randomized with 160 replications and treatments arranged in a factorial design 3 × 3, represented by A. grandis adults fed on 3 food types (fragments of banana (T1) or orange (T2) endocarp, or with cotton squares of cultivar BRS 286 (T3, control)) and three evaluation periods (30, 60, and 90 days) and after each of these periods they were fed with cotton squares for 10 days. The reproductive tract of 100% of A. grandis females fed banana endocarp, orange endocarp, and cotton squares for 30 and 60 days and then cotton squares were morphologically adequate for reproduction, and after 90 days, only 50% of those fed cotton squares were in this condition. The length of the ovarioles and the width of the mature oocyte were greater for A. grandis fed on cotton squares and smaller in those with banana and orange endocarps. Histological sections reveal that male testes even with strong degenerative signals are already producing spermatozoa. On the other hand, females displayed ovaries with nurse cells in the tropharium and some maturing oocytes in the vitellarium. The body length was longer and the testis area and diameter smaller in males fed on cotton squares than in those with banana and orange endocarp. Anthonomus grandis females fed for ≥90 days with alternative food sources do not recover the functionality of their reproductive tract, even after consuming, for 10 days, a diet that favors reproduction. On the other hand, the males remain with their reproductive organs functional with this condition.

Development, Survival and Reproduction of Spodoptera frugiperda (Lepidoptera: Noctuidae) Fed an Artificial Diet or on Cotton, Castor Bean and Corn Leaves.

The polyphagy of Spodoptera frugiperda (Lepidoptera: Noctuidae) renders its control difficult because variations in the phenology of host plants grown in different seasons of the year and near each other can facilitate the movement of this pest between crops. The objective of this work was to examine certain biological characteristics of S. frugiperda fed on an artificial diet or on cotton, castor bean, or corn leaves. The experimental design was in randomized blocks, with four treatments represented by S. frugiperda caterpillars fed an artificial diet (T1) or pieces of cotton (T2), castor bean (T3) or corn (T4) leaves with five replications (five caterpillars per replication). The duration and survival of the egg, larva, pre-pupa, pupa and egg-adult period and the reproductive characteristics of this insect were determined. The survival, development and reproduction data of S. frugiperda originated from individuals reared with cotton and castor bean leaves were lower than those fed on corn leaves or an artificial diet. The number of nonviable eggs laid by females originated from caterpillars fed on castor bean leaves was higher than those fed on cotton and corn leaves or an artificial diet. The very higher number of unviable S. frugiperda eggs resulting from castor leaves can reduce outbreaks of this pest in cotton and corn crops after the cultivation of that plant, or by intercropping with this plant, in the main producing regions of Brazil.

Influence of Mineral Particle Films and Biomaterials on Guava Fruits and Implications for the Oviposition of Anastrepha obliqua (Macquart) (Diptera: Tephritidae).

Anastrepha obliqua (Macquart, 1835) is an important pest of tropical fruits, especially Anacardiaceae and Myrtaceae, in the Americas. The objective of this study was to evaluate the influence of mineral films and biomaterials on the coloring of guava fruits (Psidium guajava L.) and implications for the oviposition of A. obliqua. Before the bioassays, color, firmness characteristics, total soluble solids, pH, and titratable acidity were determined to characterize the maturation stage of the fruits. Pieces of guava fruit covered in aluminum foil were immersed in suspensions of mineral particles (Surround® WP kaolin; kaolins 605, 607, 608, and 611; and talc) and biomaterials (chitosan, cassava and potato starch, and guar gum) and distilled water (control). After drying, the fruits were exposed to two A. obliqua pairs for 48 h in choice and non-choice tests, and the numbers of eggs per fruit were counted. Mineral films (Surround® WP kaolin, and kaolins 605, 607, 608, and 611) and biomaterials (cassava and potato starch) interfered with the color of guava (luminosity, chroma, and hue angle), inhibiting the oviposition of A. obliqua. Talc, chitosan, and guar gum did not influence the oviposition of A. obliqua in guava.

Biological aspects of Caligo teucer (Lepidoptera: Nymphalidae) with banana tree leaves

ABSTRACT Caligo teucer (Linnaeus, 1758) is widely distributed in Argentina, Bolivia, Brazil and Ecuador. The objective was to study biological aspects of Caligo teucer japetus Stichel, 1903 with banana leaves, Musa sapientium L. (Zingiberales: Musaceae), in the butterfly garden, under environmental conditions, and in the laboratory of biological control of insects at the Universidade Federal de Viçosa in Viçosa, Minas Gerais state, Brazil at 24 ± 2 oC, 68 ± 10% relative humidity and 12 hours photophase. The duration of the egg incubation, larvae, pupa and egg to adult periods of C. teucer japetus were, respectively, 11.8 ± 0.1; 53.9 ± 0.9; 17.9 ± 0.3 and 82.6 ± 1.0 days for females, and 11.8 ± 0.1; 50.3 ± 0.6; 18.4 ± 0.3 and 79.4 ± 0.6 days for males in cages in the laboratory. The longevity of C. teucer japetus adults was 26.0 ± 10.4 and 47.5 ± 8.7 for females and 24.7 ± 3.5 and 35.4 ± 15.7 for males in the butterfly garden and in laboratory cages, respectively. The high survival and the relatively short period of development of its immature stages confirm that banana leaves are an adequate food substrate for the development and survival of Caligo teucer japetus.

Spatial and temporal distribution of cotton squares and small cotton bolls fallen on ground after damage by boll weevil and the efficiency of the equipment used to collect them / Distribuição espacial e temporal dos botões florais e pequenas maçãs de algodão caídas ao solo danificadas pelo bicudo e eficiência de equipamento para coletá-los

ABSTRACT: In this study, we determined the spatial and temporal distribution of fallen cotton squares and small cotton bolls fallen damaged by boll weevil and the efficiency and time interval of the equipment used to collect cotton samples. Spatial and temporal distribution of cotton squares and small cotton bolls fallen on the soil damaged by boll weevil among cotton rows was determined in an experimental design of randomized blocks in a factorial arrangement of 4x3, represented by soil surface tracks located at 1-11cm, 12-22cm, 23-33cm, and 34-44cm away from the planting row of cotton plants 70, 85, and 100 days of age. Efficiency and collection time interval of the cotton samples fallen on the soil infested by boll weevil by plastic rakes that were straight or fan-shaped, big broom, collector instrument model CNPA and aspirator of leaves ‘Trapp’ were determined in randomized block design with five treatments, 10 repetitions for each. Results demonstrated that the collection of cotton samples must be performed with greater attention to soil strips located below the cotton top projection and aspirator ‘Trapp’ of leaves was more appropriate for the operation as it used less time of collection with similar efficiency to other available equipment.

RESUMO: Neste estudo, determinou-se a distribuição espacial e temporal dos botões florais e pequenas maçãs de algodoeiros caídas ao solo danificadas pelo bicudo e a eficiência de equipamentos para coletá-las. A distribuição espacial e temporal dos botões florais e pequenas maçãs de algodoeiros caídas ao solo danificadas pelo bicudo entre as fileiras de algodão foram determinadas em delineamento experimental de blocos ao acaso em arranjo fatorial 4x3, representado por faixas de superfície de solo localizadas entre 1-11cm; 12-22cm; 23-33cm e 34-44cm de distância da fileira de plantio em algodoeiros com 70, 85 e 100 dias de idade. A eficiência de coleta dos botões florais e pequenas maçãs caídas ao solo danificado pelo bicudo pelos rastelos plásticos em leque e reto, vassourão, catador modelo CNPA e aspirador de folhas “Trapp” foi determinado em delineamento de blocos ao acaso com cinco tratamentos e 10 repetições. Os resultados demonstraram que a coleta dos botões florais e pequenas maçãs caídas ao solo devem ser realizadas com maior atenção nas faixas de solo localizada abaixo da projeção da copa do algodoeiro e que o aspirador “Trapp” se mostrou mais adequado para essa operação porque gastou menos tempo para coletar essas estruturas vegetais, embora tenha apresentado eficiência semelhante aos demais equipamentos.

Development and survival of nymphs of Podisus nigrispinus (Heteroptera: Pentatomidae) fed with caterpillars of Chlosyne lacinia saundersii (Lepidoptera: Nymphalidae)

The development and survival of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) nymphs fed on larvae of Chlosyne lacinia saundersii Doubleday & Hewitson (Lepidoptera: Nymphalidae) was studied at 25 ± 1ºC, 68 ± 10 percent relative humidity and 12 h photo phase. P. nigrispinus developed until the adult stage when fed on C. lacinia saundersii caterpillars. However, the survival rate of P. nigrispinus during early instars allowed this predator to complement its diet with other preys and to maintain its populations in areas with the sunflower culture.

Predation rate of Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae with and without defense by Podisus nigrispinus (Heteroptera: Pentatomidae)

The effect of the defense of the prey Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) on predation rates of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) females was studied. P. nigrispinus preyed 1.0, 1.4, 1.2, 3.8 and 3.0 and 0.4, 0.8, 1.6, 2.8 and 3.2 third instars of S. frugiperda larvae with and without defense, respectively, with the densities of one, two, four, six and eight larvae. The attack rate and the manipulation time were, respectively, 0.67 ± 0.39-h and 6.72 ± 2.88 h for P. nigrispinus females fed with larvae with defense and 2.51 ± 0.16-h and 0.51 ± 0.77 h for those without defense. The functional response of the predator P. nigrispinus varies with the defense and the density of the prey S. frugiperda, with larger consumption of prey without defense at higher densities.

Objetivou-se determinar o efeito da defesa da presa Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) na taxa de predação por fêmeas de Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae). Podisus nigrispinus, predou 1,0; 1,4; 1,2; 3,8; 3,0 lagartas de terceiro estádio de S. frugiperda com defesa, respectivamente, nas densidades de uma, duas, quatro, seis e oito lagartas, enquanto esses valores foram de 0,4; 0,8; 1,6; 2,8; 3,2 lagartas sem defesa, respectivamente, nessas densidades. A taxa de ataque (a) e o tempo de manipulação (Th) foram, respectivamente, de 0,67 ± 0,39-h e 6,72 ± 2,88 horas para fêmeas de P. nigrispinus alimentadas com lagartas com defesa e de 2,51 ± 0,16-h e 0,51 ± 0,77 horas para aquelas sem defesa. A resposta funcional do predador P. nigrispinus varia com a defesa e a densidade da presa S. frugiperda, com maior consumo de presas sem defesa em altas densidades.

Efeitos da temperatura no desenvolvimento, fecundidade e longevidade de Gargaphia torresi Lima (Hemiptera, Tingidae) / Effects of temperature on the development, fecundity, and longevity of Gargaphia torresi Lima (Hemiptera, Tingidae)

O desenvolvimento de Gargaphia torresi Lima em folhas de algodão foi estudado em câmara climatizada a 20, 23, 25, 28 e 30ºC, umidade relativa de 70±10 por cento e fotofase de 12h. O período de incubação variou de 11 (20ºC) a 4 (30ºC) dias; o estágio ninfal de indivíduos que originaram fêmeas e machos variou de 20,8 (20ºC) a 8,3 (30ºC) dias e de 28,8 (20ºC) e 8,6 (30ºC) dias, respectivamente. O desenvolvimento dos estágios imaturos para indivíduos que originaram fêmeas e machos variou de 31,8 (20ºC) a 12,3 (30ºC) dias e de 31,5 (20ºC) a 12,6 (30ºC) dias, respectivamente. Os valores de longevidade e fecundidade foram inversamente proporcionais ao aumento da temperatura. As exigências térmicas (K) e temperaturas-base (Tb) foram estimadas para cada um dos estágios imaturos e de ovo à emergência de adultos (machos e fêmeas) de acordo com a Lei de Reamur e com o método de intercecção de X, respectivamente. Os estágios imaturos para indivíduos que originaram fêmeas e machos adultos requereram 209,4 e 220,3 graus-dia da oviposição à emergência do adulto, respectivamente, acima dos limites inferiores de 13,9 e 13,6ºC.