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Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Phytopathologie. Zoologie agricole. Protection des cultures et des forets, Phytopathology. Animal pests. Plant and forest protection, Protozoaires. Invertébrés, Protozoa. Invertebrates, Signalements, symptômes, dégâts, importance économique, surveillance des populations, Records, symptoms, damages, economic importance, population surveys, Angiospermae, Arthropoda, Coreidae, Dicotyledones, Déprédateur, Pest, Plaga, Heteroptera, Insecta, Invertebrata, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Relation animal végétal, Animal plant relation, Relación animal vegetal, Spermatophyta, Comportement alimentaire, Feeding behavior, Conducta alimenticia, Comportement déprédateur, Pest behavior, Conducta depredadora, Culture tropicale, Tropical crop, Cultivo tropical, Cycle développement, Life cycle, Ciclo desarrollo, Etude en laboratoire, Laboratory study, Estudio en laboratorio, Glycine max, Hôte substitution, Host substitution, Huesped sustitución, Plante hôte, Host plant, Planta huesped, Survie, Survival, Sobrevivencia, Vigna unguiculata, and Clavigralla tomentosicollis

Suitability of the pods of cowpea (Vigna unguiculata (L.) Walp) and soybean (Glycine max (L.) Merrill) as food for Clavigralla tomentosicollis was determined in the laboratory using development, food substitution and host switch experiments. On soybean pods, nymphs survived for 8 days and adults for 12 days; on cowpea, all nymphal instars developed into adults and lived for 80-100 days. Teneral adults that were switched from cowpea to soybean lost weight, while adults that were moved from soybean to cowpea gained weight with slight differences between the sexes. The shortest critical survival threshold (duration with at least 50% survival) of adults on cowpea was greater than the longest on soybean. The likelihood of C. tomentosicollis exploiting soybean as a trophic niche in areas of tropical Africa where production of this crop is on the increase and usually contiguous with cowpea production, is discussed.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Entomology, Entomologie, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Ecologie animale, vegetale et microbienne, Animal, plant and microbial ecology, Ecologie animale et végétale, Animal and plant ecology, Autoécologie, Autoecology, Végétaux et champignons, Plants and fungi, Phytopathologie. Zoologie agricole. Protection des cultures et des forets, Phytopathology. Animal pests. Plant and forest protection, Protozoaires. Invertébrés, Protozoa. Invertebrates, Signalements, symptômes, dégâts, importance économique, surveillance des populations, Records, symptoms, damages, economic importance, population surveys, Angiospermae, Arthropoda, Dicotyledones, Heteroptera, Insecta, Invertebrata, Leguminosae, Légumineuse grain, Grain legume, Leguminosa grano, Relation animal végétal, Animal plant relation, Relación animal vegetal, Spermatophyta, Coreidae, Dégât, Damage, Estrago, Déprédateur, Pest, Plaga, Gousse, Pod, Vaina, Histopathologie, Histopathology, Histopatología, Plante hôte, Host plant, Planta huesped, Tissu végétal, Plant tissue, Tejido vegetal, and Vigna unguiculata

Histological studies were conducted on cowpea pods fed upon by the coreoid pod-sucking bugs, Anoplocnemis curvipes (Fabricius), Clavigralla tomentosicollis Stal, C. shadabi Dolling, Riptortus dentipes (Fabricius) and Mirperus jaculus (Thunberg). Various degrees of tissue and cellular disruption were apparent, especially in the brachysclereids. They were manifested in terms of plasmolysis, cell enlargement and cell wall disintegration depending on the coreoid species involved. The feeding site and its periphery had all the cells of the brachysclereids plasmolysed, with the parenchyma having broken cell walls in the case of A. curvipes. Riptortus dentipes and M. jaculus showed similar patterns of feeding activity but less extensive levels of damage. The Clavigralla spp., however, caused cell enlargement in the brachysclereids, and broken cell walls in both the brachysclereids and the parenchyma. Damage symptoms were observed in cells far away from the feeding sites of the bugs, suggesting the possibility of sucrase activity which has been reported to cause osmotic pump feeding in the Coreidae.

Agronomy, agriculture, phytopathology, Agronomie, agriculture, phytopathologie, Ecology, Ecologie, Entomology, Entomologie, Environment, Environnement, Sciences biologiques et medicales, Biological and medical sciences, Sciences biologiques fondamentales et appliquees. Psychologie, Fundamental and applied biological sciences. Psychology, Phytopathologie. Zoologie agricole. Protection des cultures et des forets, Phytopathology. Animal pests. Plant and forest protection, Protozoaires. Invertébrés, Protozoa. Invertebrates, Lutte, Control, Lutte biologique, Biological control, Angiospermae, Arthropoda, Dicotyledones, Entomophage, Entomophagous, Entomófago, Heteroptera, Hymenoptera, Insecta, Invertebrata, Leguminosae, Relation hôte parasite, Host parasite relation, Relación huesped parásito, Spermatophyta, Animal auxiliaire, Beneficial animal, Animal benéfico, Coreidae, Densité population, Population density, Densidad población, Déprédateur, Pest, Plaga, Efficacité parasitaire, Parasitic efficiency, Eficacia parasitaria, Hôte, Host, Huesped, Lutte biologique, Biological control, Lucha biológica, Légumineuse grain, Grain legume, Leguminosa grano, Oophage, Oophagous, Oófago, Parasitoïde, Parasitoid, Parasitoide, Scelionidae, Taux parasitisme, Parasitism rate, Tasa parasitismo, Variation saisonnière, Seasonal variation, Variación estacional, Vigna unguiculata, Clavigralla tomentosicollis, Gryon fulviventris, and Nigeria du Nord

Field surveys were conducted on cowpea and pigeon pea in 1995 and 1996 to assess the effect of indigenous egg parasitoids on populations of Clavigralla tomentosicollis Stål in northern Nigeria. From the egg masses of C. tomentosicollis, three species of Hymenoptera belonging to three families, namel Anastatus sp. (Eupelmidae), Ooencyrtus utetheisae (Risbec) (Encyrtidae), and Gryon fulviventris (Crawford) (Scelionidae), were recorded. Among them, G. fulviventris was found to be the most abundant parasitoid. Of a total of 3,502 egg masses collected on cowpea from four geographical locations, 2,587 (73.9%) were found to contain at least one egg parasitized by G fulviventris. From 56,072 eggs discovered, it parasitized 38,935 (69.4%). Overall, 74,724 eggs were collected from the four different locations and of these 52% were parasitized by G. fulviventris. However, parasitism rates varied with time and location. At one of the study sites (Minjibir, Kano) where weekly samples were collected throughout the growing season, the discovery efficiency, exploitation efficiency, and overall percentage parasitism increased significantly from July to November. Also, the proportion of eggs parasitized was found to be inversely related to the size of the egg mass. These findings are discussed in relation to the potential contribution of biological control in the integrated pest management of this economically important pest.