Lonchaeidae (Diptera) species and their host plants in the Cerrado biome in the state of Piauí, Brazil

Arq. Inst. Biol., v.86, 1-5, e0242018, 2019 RESUMO: Algumas espécies de Lonchaeidae (Diptera) são consi‐ deradas pragas frugívoras e polífagas, com ampla distribuição geo‐ gráfica 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 espé‐ cies 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), per‐ tencentes 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 infes‐ tação. Uma espécie de Neosilba foi considerada um invasor primá‐ rio em laranjas. Esses resultados são os primeiros relatos de espé‐ cies de Lonchaeidae e suas plantas hospedeiras no estado do Piauí.


PALAVRAS-CHAVE:
The first studies on Lonchaeidae described its species as secondary pests due to their attack on already infested fruits by Tephritidae (STRIKIS; PRADO, 2005). However, new studies characterize some of these species as primary, polyphagous, and economically important pests for fruit crops (UCHÔA-FERNANDES et al., 2002;RAGA et al., 2015;RIQUELME et al., 2015).
Studies Some species of Lonchaeidae are frugivorous and polyphagous pests and are widely distributed throughout Brazil. Information on the relationship between flies and their host plants is important to study spatial distribution of frugivorous flies and their use of host plants. These studies allow us to know the behavior of these insect pests in Brazil's atypical environments, such as the Cerrado biome, in the state of Piauí, and the Lonchaeidae's potential to be a primary invader of fruits in these environments.
Therefore, our goals were to identify the Lonchaeidae fly species and their host plants in the state of Piauí, located in the Cerrado biome, and to assess if these insects are primary invaders of fruits in this region.
Fruit samples were collected in the municipality of Corrente based on the availability in rural and urban areas and were separated by species. Then, they were counted, weighed, and placed in plastic trays (36 × 27 × 12 cm) containing sterilized sand. Thereafter, they were labeled and covered with cotton cloth fixed with rubber band. The pupae were sieved and separated every seven days and were placed in 500-mL-glass pots containing moistened sand, which were sealed with cotton cloth fixed with rubber band. The adults were killed by freezing at -11°C, and then transferred to labeled vials with alcohol 70%. The infestation index and infestation frequency were evaluated to establish the status of the host plant in relation to its susceptibility to attack by frugivorous Lonchaeidae.
The infestation index used was the number of pupae divided by the number of fruit and the number of pupae divided by the fruit's weight (kg). The infestation frequency used was the number of infested fruit samples divided by the total of samples of each species multiplied by 100 and the number of flies of a species divided by the total number of flies multiplied by 100 (SOUZA FILHO et al., 2000;ARAÚJO et al., 2005).
Neosilba species were collected from 10 fruit species from seven botanical families in the Cerrado biome of Piauí. Neosilba flies were related to native fruit species and fruit species that were introduced to the Cerrado biome, infesting 22 of them (UCHÔA-FERNANDES et al., 2002); and in the Semi-Arid region, infesting eight of these species (ARAÚJO; .
The low number of hosts found in the Semi-Arid region by these authors, and in the Cerrado biome of Piauí in the present work, is possibly due to the low availability of fleshy fruits, which are potential hosts of frugivorous flies (ARAÚJO; . Oranges had the largest number of adult Lonchaeidae (Table 1). Several fruit flies use oranges as hosts, such as the Anastrepha Schiner, Ceratitis capitata (Wiedemann, 1824) and Neosilba spp. (SOUZA et al., 2008). Moreover, N. zadolicha collected in orange samples was the only fruit fly considered a primary invader of oranges in the Cerrado biome of Piauí.
Neosilba zadolicha was the most common and polyphagous fly species. It was found in six species of five plant families.
This fly species has the widest geographical distribution and host diversity in Brazil and is considered an important fruit pest grown in the Northeast and Southeast regions of the country (LOPES et al., 2007;RAGA et al., 2015).
However, N. inesperata and N. pendula did not show signs of polyphagia in the Cerrado biome, specifically in the state of Piauí. These species were considered polyphagous in the state of São Paulo, with infestations of 37 (N. inesperata) and 21 (N. pendula) botanical species (RAGA et al., 2015). Moreover, N. pendula was considered an important primary invader of barbados cherry in the Semi-Arid region (ARAÚJO; . Although the Semi-Arid region and the Cerrado biome in the state of Piauí present similar environmental conditions, N. pendula was not considered a primary invader of the fruit species in Piauí.
Fly species of the Lonchaeidae family infests native fruit species and fruit species that were introduced to the Cerrado biome in the state of Piauí, especially typical fruit species that are commonly found in this region, such as those from the genus Spondias.
Orange is an economic important fruit and the most produced in Brazil. This fruit is not cultivated commercially in the southern Piauí. However, the occurrence of infestation by N. zadolicha, considered a primary invader of this fruit in this region, is an important factor for the commercial production of oranges.