Pollinators provide an essential service to natural ecosystems and agriculture. In tomatoes flowers, anthers are poricidal, pollen may drop from their pore when flowers are shaken by the wind. However, bees that vibrate these anthers increase pollen load on the stigma and in fruit production. The present study aimed to identify the pollinator richness of tomato flowers and investigate their morphological and functional traits related to the plant-pollinator interaction in plantations of Central Brazil. The time of anthesis, flower duration, and the number and viability of pollen grains and ovules were recorded. Floral visitors were observed and collected. Flower buds opened around 6h30 and closed around 18h00. They reopened on the following day at the same time in the morning, lasting on average 48 hours. The highest pollen availability occurred during the first hours of anthesis. Afterwards, the number of pollen grains declined, especially between 10h00 to 12h00, which is consistent with the pollinator visitation pattern. Forty bee species were found in the tomato fields, 30 of which were considered pollinators. We found that during the flowering period, plants offered an enormous amount of pollen to their visitors. These may explain the high richness and amount of bees that visit the tomato flowers in the study areas. The period of pollen availability and depletion throughout the day overlapped with the bees foraging period, suggesting that bees are highly effective in removing pollen grains from anthers. Many of these grains probably land on the stigma of the same flower, leading to self-pollination and subsequent fruit development. Native bees (Exomalopsis spp.) are effective pollinators of tomato flowers and are likely to contribute to increasing crop productivity. On the other hand, here tomato flowers offer large amounts of pollen resource to a high richness and amount of bees, showing a strong plant-pollinator interaction in the study agroecosystem.Keywords: agroecosystem, buzz pollination, Exomalopsis, poricidal anther, Solanum lycopersicum L. Alta riqueza de espécies de polinizadores nativos em plantações Brasileiras de tomateiro ResumoPolinizadores fornecer um serviço essencial para os ecossistemas naturais e para agricultura.

In the present paper we investigated the insect gall distribution along savanna and forest sites in the Floresta

The tomato plant has a specific relationship with native pollinators because the form of its flowers is adapted to buzz pollination carried out by some pollen-gatherer bees that vibrate their indirect flight muscles to obtain that floral resource. The absence and the low density of these bees in tomato fields can lead to pollination deficits for crop. The aim of this study is to demonstrate that open tomato flowers, probably visited by native pollinator, have greater pollen load on their stigma than unvisited flowers. Another objective is to show that this great pollen load increases fruit production. We selected crops of the Italian tomato cultivar in areas of the State of Goiás, Brazil. Thirty seven plants of three crops each had one inflorescence bagged in the field. Bagged and non-bagged flowers had their stigmas collected and the amount of pollen on their surfaces was quantified. For the comparison of fruit production, we monitored bagged and not-bagged inflorescences and after 40 days, their fruits were counted, weighed, measured and had their seeds counted. The amount of pollen grains on the stigma of flowers available to pollinators was higher than that on the stigma of bagged flowers. On average, fruit production was larger in not-bagged inflorescences than in bagged inflorescences. In addition, not-bagged flowers produced heavier fruits than did bagged flowers. There was a significant difference in the number of seeds between treatments, with significantly more seeds in the non-bagged fruit. Our results show that native bees buzz-pollinate tomato flowers, increasing the pollen load on their stigma and consequently fruit production and quality.

ABSTRACT. We investigated the insect gall distribution along savanna (xeric) and forest (mesic) vegetation in the Floresta Nacional de Silvânia, Goiás, Brazil. We tested if the insect gall diversity is higher in the xeric vegetation than in the mesic vegetation, as predicted by the hygrothermal stress hypothesis. The insect gall fauna was surveyed between December 2009 and June 2010 in two transects established each vegetation type. In total we found 186 insect gall morphotypes, distributed on 35 botanical families and 61 plant species. Cecidomyiidae (Diptera) induced the most insect galls (34.1%), and the plant family Fabaceae had the greatest richness of insect gall morphotypes (18). We recorded 99 insect gall morphotypes in the forest and 87 morphotypes in the savanna vegetation, being that none insect gall morphotype occurred in both habitats. We found that the insect gall richness and abundance did not diff er between forest and savanna transects. On the other hand, the estimated insect gall richness was higher in the forest than in the savanna. Our fi ndings contrary the hygrothermal stress hypothesis possibly because forest habitats have higher plant architecture complexity and occurrence of super-host taxa than the savanna habitats.KEYWORDS. Cecidomyiidae, Cerrado, Fabaceae, plant-insect interaction.RESUMO. Distribuição de galhas de insetos em habitats xéricos e mésicos da Floresta Nacional de Silvânia, Brasil. Foi inventariada a distribuição de galhas de insetos ao longo de vegetações savânicas (xéricas) e fl orestais (mésicas) na Floresta Nacional de Silvânia, Goiás, Brasil. O estudo testou se a diversidade de insetos galhadores é maior na vegetação xérica do que na vegetação mésica, como predito pela hipótese do estresse higrotermal. A fauna de galhadores foi amostrada entre dezembro de 2009 e junho de 2010 em dois transectos estabelecidos em cada tipo de vegetação. No total foram encontrados 186 morfotipos de galhas de insetos, distribuídos em 35 famílias e 61 espécies de plantas. Cecidomyiidae (Diptera) induziu a maioria das galhas de insetos (34,1%) e a família Fabaceae teve a maior riqueza de morfotipos de galhas (18). Foram registrados 99 morfotipos de galhas de insetos na fl oresta e 87 morfotipos no cerrado, sendo que nenhum morfotipo de galha ocorreu em ambos os habitats. A riqueza e a abundância de galhas de insetos não diferiram entre os transectos de fl oresta e cerrado. Por outro lado, a riqueza estimada de galhas de insetos foi maior na fl oresta do que no cerrado. Esses resultados contrariam a hipótese do estresse higrotermal possivelmente devido aos habitats fl orestais apresentarem maior complexidade arquitetônica das plantas e ocorrência de táxons super-hospedeiros do que os hábitats savânicos.PALAVRAS-CHAVE. Cecidomyiidae, Cerrado, Fabaceae, interação inseto-planta.