José Ricardo Cure

Tritrophic analysis of the coffee (Coffea arabica) - coffee berry borer [Hypothenemus hampei (Ferrari)] - parasitoid system

An age-mass structured multi-year tritrophic simulation model of the coffee (Coffea arabica var. mundo novo) - coffee berry borer [Hypothenemus hampei (Ferrari)], borer - three parasitoid system was developed. Three years of extensive plant drymatter data and one year of field data on borer dynamics were collected at Londrina, PR, Brazil. The allometric relationships and parameter for plant drymatter allocation were estimated from the field data, but the parameters for borer and its three parasitoids were summarized from the literature. Initial levels of soil factors (e.g., nitrogen and water) and observed weather data were used to drive the model. The model is largely independent of the field data, yet it simulated the dynamics of plant branching, fruiting and drymatter growth of plant subunits. Simulation results suggest that of the three parasitoids commonly introduced to control the borer, only the eulophid adult endo-parasitoid (Phymastichus coffea La Salle) has the demographic characteristics to potentially regulate borer populations. The effects of harvesting, cleanup of abscised berries, inundative releases of parasitoids and pesticides with various toxicity and persistence characteristics on borer dynamics were evaluated. The model is very flexible, and may provide a sound foundation for incorporating new findings, new varieties, and the biology of new natural enemies worldwide

Fenologia e dinâmica populacional da broca do café Hypothenemus hampei (Ferr.) relacionadas às fases de desenvolvimento do fruto

A dinâmica populacional da broca do cafe, Hypothenemus hampei Ferrari foi estudada em Paula Cândido, MG, Brasil (20o S; 660 m altitude, 1391 mm precipitacao anual media, 18o C temperatura media anual). Semanalmente, de novembro de 1992 a maio de 1993, acompanhou-se: os estadios de desenvolvimento fenologico dos frutos de cafe (chumbinho, verde, inicio de maturacao, cereja e seco); os numeros de frutos brocados em cada estadio fenologico; e o numero de individuos da broca em cada estadio de desenvolvimento, presentes nos frutos brocados. Verificou-se que existem no minimo tres geracoes completas da broca desenvolvendo-se durante o periodo de formacao dos frutos. A preferencia da broca para atacar frutos em diferentes estagios de maturacao e descrita por uma equacao logistica em funcao da idade dos frutos. Depois de infestarem o fruto as femeas aguardam ate o inicio da maturacao dos frutos para iniciar a oviposicao. Os resultados indicam que medidas de controle devem ser dirigidas ao periodo compreendido entre o final da safra e o inicio da maturacao dos frutos na safra seguinte, atingindo os adultos antes do inicio da oviposicao.

Atividade predadora e parasítica de Diglyphus begini (Ashm.) (Hymenoptera: Eulophidae) sobre Liriomyza huidobrensis (Blanch.) (Diptera: Agromyzidae) em cultivos de Gypsophila paniculata L.

Diglyphus begini (Ashm.), a biological control agent of the leaf miner Liriomyza huidobrensis (Blanch.), has a two-fold effect on pest control: host-feeding and parasitism. The proportional effect of the two actions was studied in a commercial greenhouse facility with Gypsophila paniculata L. plants, export quality. Effects of host feeding were observed before the parasitism effects. By the end of the vegetative cycle of the crop, both mortality factors had a combined effect of 70% control of the leaf miner. After flowering, this control may reach 90% without the need of insecticides. It is emphasized that the predation effect is usually neglected in evaluations of monitoring and that the parasitoid actions is frequently underestimed.

Gyne and Drone Production in Bombus Atratus (Hymenoptera: Apidae)

Abstract For over a decade, our research group has studied the biology of the native bumblebee, Bombus atratus, to investigate the feasibility of using it to pollinate crops such as tomato, strawberry, blackberry and peppers. Traditionally, captive breeding has depended on the use of captured wild queens to initiate the colonies. The goal of the current work is to investigate conditions required to produce new queens and drones in captivity. In this study, 31 colonies were evaluated under either greenhouse or open field conditions over a 15 month period. A total of 1492 drones (D) and 737 gynes (G, i.e., virgin queens) were produced by all colonies, with 16 colonies producing both drones and gynes (D&G), 11 producing only drones (D) and 4 producing neither. Some of the D&G colonies had more than one sexual phase, but no colonies produced exclusively gynes. More drones and fewer gynes were produced per colony under greenhouse conditions with the highest number of drones produced by D&G colonies. The numbers of immature stages per cell declined in colonies as increasingly more resources were allocated to the production of gynes and the maintenance of increased nest temperature.

Padronização da criação de Tetranychus urticae Koch (Acari: Tetranychidae) em feijoeiro (Phaseolus vulgaris): idade da planta e tempo de colheita

A rearing technique was standardized to produce Tetranychus urticae Koch on Phaseolus vulgaris (ICA Cerinza variety) as a prey of the predatory mite Phytoseiulus persimilis Athias-Henriot. Two assays were conducted to assess the following variables: 1. the most suitable plant age for mite infestation, 2. the best time to harvest the mites and reinfest the plants. In the first experiment, four-, five-, six-, and seven-week-old plants of P. vulgaris were infested with six T. urticae per foliole. The lower plant stratum exhibited the largest number of mites regardless of plant age. However, four-week-old plants had the larger average number of individuals. In the second experiment four-week-old plants were infested with 0.5 female mite/cm(2) of leaf. The number of individuals per instar of T. urticae was recorded weekly. The highest mite production occurred between four and five weeks after infestation, indicating this to be the most suitable for mite harvesting and for plant reinfestation.

A Simulation Model of the Mass Rearing of Tetranychus urticae Koch (Acari: Tetranychidae) on Beans

The supply of predatory mites as natural enemies is a key component to guarantee the success of biological pest control programs as alternatives to chemical control in commercial crops. To meet the demand for a supply of biologicals, the mass rearing of natural enemies is an option, and the first step must be to develop a standardized system that maximizes the production of prey. One choice for this first step is to use simulation models that can evaluate scenarios that are difficult or complex to address experimentally. In this work, a model was developed to evaluate the current management conditions for the mass rearing of the pest mite Tetranychus urticae Koch. Our aim was to identify alternative scenarios to maximize mite production through mass rearing that could be evaluated in real systems. We assumed that populations of T. urticae were regulated by the conditions of supply-demand theory and modeled the age structure, temperature effects, and individual phenology of T. urticae. The supply-demand theory of resources was used to regulate populations, which involved structured ages and temperature effects for the different stages in the development of individuals. We used the functional response and the paradigm of metabolic pool models to describe resource acquisition and allocation. We demonstrated that 7- to 14-day-old plants infested with 45 or 62 T. urticae/plant could reach 25,000 individuals/plant, being 50% of these preys at the preferred stages by the predator Phytoseiulus persimilis Athias-Henriot. Our theoretical model requires validation in experimental/real systems of mass rearing to better verify the validity of all of the parameters and predictions before commercial implementation.

Two new species of Caenohalictus Cameron, 1903 (Hymenoptera: Halictidae) from Colombia

This paper describes and illustrates females and males of two species of Caenohalictus Cameron, 1903: C. sabanaensis n.sp. and C. alexandrei n.sp. Both species are commonly collected in the Savanna of Bogotá, a high plateau in the central region of the Eastern Andes of Colombia. Notes on morphological variations within and among the species, as well as comments on some biological aspects and images of diagnostic structures are provided.