Luis Sánchez Ch. and Ingrid Aguilar M.

1. Conservation of native trees and the indigenous bees in Costa Rica: nest tree selectivity and melliferous plants Luis Sánchez Ch. and Ingrid Aguilar M.

2. Introduction √ Stingless bees inhabitants of tropical regions

3. Introduction STINGLESS BEES DIVERSITY (APIDAE: MELIPONINI) Around 400 species in the world √ In Costa Rica: 60 species, 15%

4. Introduction STINGLESS BEES DIVERSITY (APIDAE: MELIPONINI) √ 12 genera Trigona, one genus Melipona

5. Introduction √ Live permanent colonies

6. Introduction √ Generalist in the use of food sources The species specific characteristics (bee size, colony size, communication, etc.) play a role in the distention of the trophic niche for every species.

7. Introduction √ Important pollinators of many flowering plants According Roubik: “ SB the most important insect groups, in pollination of native flora: GREAT DIVERSITY & HIGH ABUNDANCE Melipona beecheii

8. Main objective The aims of this study was to increase our knowledge about the principal plants species that are used as pollen resources by the stingless bee species and nest site selection in a tropical dry area of Costa Rica.

9. Aspects studied • January to April 1997, pollen loads were collected bi-weekly from returning foragers of Tetragonisca angustula. While, pollen from flowering plants was taken to create a reference collection of the pollen types. • Inventory of all trees (trunk diameter at breast height (dbh) ≥ 20 cm (forest plot 1ha; farm plot 5.8h). • Pozo Azul de Abangares, Guanacaste Province.

10. Results:Pollen spectrum • T. angustula collected a total number of 32 pollen types • Asteraceae, Fabaceae and Sapindaceae were the dominant families in three colonies of T. angustula. • Simpson’s index was 0.52 (intermediate record of diversity) • Guazuma ulmifolia, Sapindus saponaria and Trema micrantha dominated in several weeks

11. Results:Pollen spectrum Sapindus saponariaL. Trema micrantha(L) Blume Guazuma ulmifoliaLam.

13. Blooming syndromes. Plant species used by T. angustula • ++ Massive Blossom 12 • + Moderable Blossom 7 • - Solitary flowers 6 Cordia alliodora Andira inermis Cochlospermum vitifolium

14. Blooming syndromes. Plant species used by T. angustula • ++ Massive Blossom syndrome CONSIDERATIONS Way of nectar “Despite feed resources are plenty to the bees. They are moving between the massive blossom trees, checking the sudden changes on nectar concentration…..More # of visits to flower of different individuals……MORE CROSS-POLLINATION” (Frankie & Haber, 1983). Dioicium Before 70ts tress> self-compatibles…. Hyper-dispersion Self-incompatibility are prevalent dioics are frequent CROSS-POLLINATION services

15. Tree speciesBee species • Anacardiun excelsumScaptotrigona pectoralis • Bravaisia integerrimaScaptotrigona pectoralis • Clarisia bifloraScaptotrigona pectoralis, Oxytrigona mellicolor, Tetragonisca angustula • Cordia alliodora Tetragona dorsalis ziegleri,Tetragonisca angustula,Nannotrigona testaceircornis perilampoides • Diphysa americana Tetragonisca angustula • Ficus sp. Scaptotrigona pectoralis, Melipona beecheii • Ficus trachelosyceTetragonisca angustula • Gliricidia sepiumTetragonisca angustula • Lonchocarpus lasiotropis Nannotrigona testaceircornis perilampoides • Myrospermum frutescensCephalotrigona capitata zexmeniae • Tabebuia ochraceaCephalotrigona capitata zexmeniae

16. Table 2. Tree species/ nest site selection reported (Apidae,Meliponini) Tree species # bee species Country Reported use ________________________________________________________ Pithecellobium saman* 4 Venezuela N, 1, 2,3 Spondias mombin* 1 Venezuela P, N, 1,2 Albizia caribensis* 3 Venezuela - Lonchocarpus pictus* 2 Venezuela P, N, 1, 2 Anarcadium excelsum ** 1 Costa Rica N, 1, 3 Ficus sp**+*** 2 Costa Rica P,2 Lonchocarpus lasiotropis ** 1 Costa Rica - Ficus trachelosyce ** 1 Costa Rica P, 2 Bravaisia integerrima ** 1 Costa Rica N, P, 2 Clarisia biflora ** 3 Costa Rica - Tabebuia ochracea** 1 Costa Rica N, 1, 3 Diiphysa americana** 1 Costa Rica 3 Cordia alliodora** 3 Costa Rica P, N, 1, 2, 3 Myrospermum frutescens** 2 Costa Rica N,1, 3 Bursera simaruba** 1 Costa Rica P, 1, 2, 3 Gliricidia sepium**+*** 1 Costa Rica P,N, 1, 2, 3 -------------------------------------------------------------------------------------------------- *: Moreno and Cardozo, 1997 **: Aguilar and Berrocal, 1997 ***: Sánchez, 1999. Data not publ. N: nectar, P: pollen 1: honey bees, 2:Stingless bees, 3: other functions

17. Conclusions • Fabaceae, Asteraceae and Sapindaceae are important families in the pollen diet of the bees • Inga vera, Cordia alliodora and Triplaris melaenodendrum all important nectar sources, honey bees also collect pollen of these plants species in larger quantities • Pollen, collected from mass flowering plants, during a short period of time

18. The spatial distribution of resources influence diversity of pollen collected by Trigona species. • Deforestation have an effect on population structure (e.g. abundance). • Nest selection and available food sources may limit colony reproduction in several stingless bee species.

19. Thank you !