Abstract: Anastrepha fraterculus (Wiedemann) is dominant in the main guava’s crops. Guavas are an important host of A. fraterculus for providing a good performance for the immature and high reproductive capacity. We evaluated the performance of A. fraterculus in two guava varieties related to the fruit physicochemical composition under laboratory conditions. Mature-green guavas of "Tailandesa" (red pulp) and "Kumagai" (white pulp) varieties were exposed to forced infestation by A. fraterculus in laboratory. An additional sample of each variety was submitted to physicochemical analysis. Similar quantities of pupae per fruit (128.5 - 156.0) and pupal viability (85.9% and 87.5%) were obtained per variety, but "Kumagai" produced significantly more pupae of A. fraterculus per fruit mass (1000.6 pupae/kg). Pupal weight was higher in "Tailandesa" (115.3 mg/10 pupae) than "Kumagai" (82.6 mg/10 pupae). Significant positive correlations were obtained between pupae per fruit or kg versus adults per kg for both varieties. A positive correlation was observed between pupae per fruit and pupae per kg of "Kumagai" guavas. Peel and pulp firmness were inversely correlated with pupae per fruit and pupae per kg. Weight of 10 pupae of A. fraterculus was correlated with fruit weight of "Tailandesa" guavas. The multivariate analysis PCA showed a relationship between pupae per kg and peel firmness, pulp firmness, Ratio, soluble solids, and titratable acidity in "Kumagai" guava. This explains the higher infestation index pupae per kg and better reproductive performance of A. fraterculus in "Kumagai" guava.

Resumen: Anastrepha fraterculus (Wiedemann) es dominante en los principales cultivos de guayaba. Las guayabas son un hospedador importante de A. fraterculus por brindar un buen desempeño a los inmaduros y con alta capacidad reproductiva. Evaluamos el comportamiento de A. fraterculus en dos variedades de guayaba relacionados con la composición fisicoquímica del fruto en condiciones de laboratorio. Las guayabas maduras de color verde de los cultivares "Tailandesa" (pulpa roja) y "Kumagai" (pulpa blanca) fueron expuestas a la infestación forzada por A. fraterculus en el laboratorio. Una muestra adicional de cada variedad se sometió a análisis fisicoquímico. Se obtuvieron cantidades similares de pupas por fruto (128,5 - 156,0) y viabilidad de pupas (85,9% y 87,5%) por cultivar, pero "Kumagai" produjo significativamente más pupas de A. fraterculus por masa de fruto (1000,6 pupas / kg). El peso de las pupas fue mayor en "Tailandesa" (115,3 mg / 10 pupas) que en "Kumagai" (82,6 mg / 10 pupas). Se obtuvieron correlaciones positivas significativas entre pupas por fruto o kg versus adultos por kg para ambos cultivares. Se observo una correlación positiva entre pupas por fruto y pupas por kg de guayabas "Kumagai". La firmeza de la cascara y la pulpa se correlacionó inversamente con las pupas por fruto y las pupas por kg. El peso de 10 pupas de A. fraterculus se correlacionó con el peso del fruto de las guayabas "Tailandesa". El análisis multivariado PCA mostró una relación entre pupas por kg y firmeza de la cascara, firmeza de la pulpa, relación sólidos solubles y acidez titulable en la guayaba "Kumagai". Esto explica el mayor índice de infestación de pupas por kg y el mejor desempeño reproductivo de A. fraterculus en la guayaba 'Kumagai'.

RESUMO: Algumas espécies de Lonchaeidae (Diptera) são consideradas pragas frugívoras e polífagas, com ampla distribuição geográfica em regiões neotropicais. A relação mosca/planta hospedeira é de grande valor para estudos de comportamento e distribuição de moscas frugívoras. O objetivo deste trabalho foi identificar as espécies de Lonchaeidae e suas plantas hospedeiras no bioma Cerrado, especificamente no estado do Piauí, Brasil. Oitenta e um adultos (33 ♀ e 48 ♂) do gênero Neosilba McAlpine (Lonchaeidae), pertencentes às espécies Neosilba inesperata Strikis & Prado, Neosilba pendula Bezzi e Neosilba zadolicha McAlpine, foram coletados de amostras de frutas, sendo a laranja [Citrus sinensis (L.) Osbeck] e a goiaba (Psidium guajava L.) as de maiores frequências de infestação. Uma espécie de Neosilba foi considerada um invasor primário em laranjas. Esses resultados são os primeiros relatos de espécies de Lonchaeidae e suas plantas hospedeiras no estado do Piauí.

ABSTRACT: Some species of Lonchaeidae (Diptera) are considered frugivorous and polyphagous pests, and are widely distributed in Neotropical regions. The relationship between a fly and its host plant is important for studies on behavior and distribution of frugivorous flies. The objective of this work was to identify the Lonchaeidae fly species and their host plants in the Cerrado biome, specifically in the state of Piauí, Brazil. Eighty-one adults (33 ♀ and 48 ♂) from the genus Neosilba McAlpine (Lonchaeidae), represented by the species Neosilba inesperata Strikis & Prado, Neosilba pendula Bezzi, and Neosilba zadolicha McAlpine, were collected from fruit samples. Oranges [Citrus sinensis (L.) Osbeck] and guava (Psidium guajava L.) had the highest frequencies of infestation. A Neosilba species was considered a primary invader in orange. These results are the first ones reported of Lonchaeidae species and their host plants in the state of Piauí.