New host records of Aglaomelissa duckei and a compilation of host associations of Ericrocidini bees ( Hymenoptera : Apidae )

For the first time, confirmed host records are reported for the monotypic Ericrocidini genus Aglaomelissa Snelling & Brooks, 1985. Aglaomelissa duckei (Friese, 1906) emerged from trap-nests of Centris (Heterocentris) analis (Fabricius, 1804) and C. (Heterocentris) terminata Smith, 1874 from two sites in the Brazilian Amazonian region. The parasitism ratio caused by A. duckei was high, varying from 80 to 100% of the brood cells in a single trap-nest. Also, a compilation of the known host records for the species of Ericrocidini is presented and host-parasite associations are discussed. Host associations are known for seven of the 11 genera and about 17 of the 42 species of the tribe, involving a total of 34 confirmed or putative host species of Centridini bees. All species of the tribe are known to attack only nests of Centris Fabricius, 1804, except Mesoplia rufipes (Perty, 1833) that also parasitizes nests of Epicharis Klug, 1807. Although the phylogenetic relationships within Ericrocidini and among the subgenera of Centris are not well resolved, the current knowledge of the host-parasite associations points to a relatively high degree of specificity and possible coevolution between them.

. Its biology is unknown, but ROZEN (1991) collected a female of Aglaomelissa duckei (Friese, 1906), together with several females of Mesoplia rufipes (Perty, 1833), in a nesting site of Centris (Trachina) carrikeri Cockerell, 1919 in Trinidad.This author also described a first-stage larva from a host cell, and identified it as A. duckei based on the presence of an adult female flying over the nesting aggregation and on anatomical differences between it and the first instars of M. rufipes, which were found in brood cells of Epicharis albofasciata Smith, 1874 (ROZEN 1991: 33).However, this putative host record for A. duckei is questionable, because this species is considerably more slender and smaller than C. carrikeri, whose body size is more similar to that of M. rufipes, its undoubted cleptoparasite (ROZEN 1969: 24).Also, variation in size, morphology and in anatomy of bee larvae is still unclear and further studies about this is needed to help on the identification of the species (J.G.Rozen -American Museum of Natural History, pers. comm.).
Here we report confirmed parasitism by A. duckei in nests of Centris (Heterocentris) analis (Fabricius, 1804) and C. (Heterocentris) terminata Smith, 1874 from two sites in the Brazilian Amazonian region.Also, a compilation of the known host records for species of Ericrocidini is presented and hostparasite associations are discussed.

MATERIAL AND METHODS
Adults of A. duckei emerged from nests of Centris analis constructed in trap nests made of wood blocks with tunnels drilled in them and tubes made of black cardboard with diameters of 4.8 and 9.7 mm, respectively (see Tab. I).The trap nests were placed in understory sites in the forest reserves of Catuaba and Humaitá (maintained by the Universidade Federal do Acre -UFAC), located near Rio Branco, Acre, Brazil, in 1997-1998.Information on the nests of Centris terminata from Manaus, Amazonas, can be found in MORATO et al. (1999).Voucher specimens are deposited in the entomological collections of the UFAC, Universidade Federal de Viçosa (UFV), and Universidade Federal do Paraná (DZUP).
Data on host associations for other species of Ericrocidini were compiled from literature records and, in a few cases, from personal information provided by colleagues.The names of both hosts and parasites were updated according to current usage (see MOURE et al. 2007, MOURE & MELO 2007).Available evidence on parasitism was classified in four categories: A) confirmed host-parasite association, when the parasite was reared from host cells; B) probable association, when the cleptoparasitic female was observed entering the host nest; C) presumed association, when the cleptoparasitic female was collected at the nest site of host species; D) suspected association, when based only on indirect evidence (e.g., cleptoparasite and suspected host having concomitant flight activity).

RESULTS
A summary of the data on nests of C. analis and C. terminata parasitized by A. duckei is presented in table I.The parasitism ratio caused by A. duckei was high, varying from 80 to 100% of the brood cells in a single trap-nest of C. analis and 50% of the cells in nests of C. terminata.In Humaitá Reserve, four males of A. duckei and one male of C. analis emerged from a nest that was composed of five cells (nest 27, see table I).Two nests of C. analis, both from Catuaba Reserve, were completely parasitized by A. duckei.One of them had three cells and three cleptoparasitic females emerged from these cells, while in the second nest, a male of A. duckei emerged from the single cell (Tab.I).The parasitic behavior of females of A. duckei in the host nests was not studied and remains unknown.
As regards C. terminata, MORATO et al. (1999) reported an unidentified species of Mesoplia Lepeletier, 1841 that emerged from nests of this species.However, restudy of the voucher specimens deposited at UFV by GARM revealed that, in reality, they belong to A. duckei.The nests of C. terminata were also parasitized by Mesocheira bicolor Fabricius, 1804 (Tab.I).
Information on known host associations of Ericrocidini is presented in table II.Data are available for seven of the 11 genera and about 17 of the 42 species of Ericrocidini, involving a total of 34 confirmed or putative host species of Centridini bees.

DISCUSSION
All species of the tribe Ericrocidini are known to attack only nests of Centris (SNELLING & BROOKS 1985, MICHENER 2000), except Mesoplia rufipes that also parasitizes nests of Epicharis (ROZEN 1969, HILLER & WITTMANN 1994, GAGLIANONE 2005, ROCHA-FILHO et al. 2008).No information is available for the genera Ctenioschelus Romand, 1840, Cyphomelissa Schrottky, 1902, Eurytis Smith, 1854, and Hopliphora Lepeletier, 1841.Their putative host associations, however, are discussed below.Although the available information is still fragmentary, there seems to be a non-random association between the genera of Ericrocidini and the subgenera of Centris that they parasitize.Ericrocis Cresson, 1887, a genus restricted to northern Mexico and southern USA and recovered as sister-group to the remaining genera of the tribe by SNELLING & BROOKS (1985), parasitizes species of the soil-nesting subgenus Centris (Paracentris) Cameron, 1903(ROZEN & BUCHMANN 1990, ROZEN 1991).
Mesonychium Lepeletier & Serville, 1825 and Epiclopus Spinola, 1851 are closely related (SNELLING & BROOKS 1985).The first genus is widespread, ranging from Venezuela and Brazil, in the north, to central Chile and Argentina, whereas the latter is restricted to Chile and western Argentina (MICHENER 2000, MOURE & MELO 2007) Acanthopus Klug, 1807 and its allies (Cyphomelissa, Eurytis, and Hopliphora) contain the largest species of Ericrocidini bees (MICHENER 2000).Host records are known only for Acanthopus and all of them are species of Centris (Ptilotopus) Klug, 1810, whose nests are excavated in arboreal and/or epigeous mud termite nests (DUCKE 1903, SILVESTRI 1903, PICKEL 1928, ROZEN 1969, GAGLIANONE 2001).Judged by their relatively large body size and geographic distribution, the remaining three genera in this group are likely to be associated with the subgenera Centris (Aphemisia) Ayala, 2002, C. (Melacentris) Moure, 1996, andperhaps C. (Trachina) Klug, 1807.Mesoplia is the richest genus within Ericrocidini, with at least 21 species (ROCHA-FILHO & MELO, unpub.data).Moreover, it exhibits the largest range among the tribe's genera, its distribution extending from southern United States (Arizona) to northern Argentina, including the Antilles (SNELLING & BROOKS 1985).Regarding its host association, there are more known records for Mesoplia than for any other Ericrocidini genus (see references in table II).Mesoplia attacks mostly species of C. (Centris), with three known exceptions, two of them involving species of C. (Paracentris).The third exception involves attacks to nests of Epicharis by Mesoplia rufipes, an association confirmed by several studies (ROZEN 1969, HILLER & WITTMANN 1994, GAGLIANONE 2005, ROCHA-FILHO et al. 2008) and involving at least three subgenera and five species of Epicharis.Use of Epicharis as hosts by M. rufipes is undoubtedly a derived feature within Ericrocidini.
According to SNELLING & BROOKS (1985), Mesocheira Lepeletier & Serville, 1825, Ctenioschelus, and Aglaomelissa form a clade supported by several unique synapomorphies.Except A Confirmed host-parasite association: when the parasite was reared from host cells; B probable association: when the cleptoparasitic female was observed entering the host nest; C presumed association: when the cleptoparasitic female was collected at the nest site of host species; D suspected association: when based only on indirect evidence (e.g., parasite and suspected host having concomitant flight activity).
for the two species of Ctenioschelus, the other two genera contain each a single species.Mesocheira bicolor is known to parasitize only species of Centris (Hemisiella) Moure, 1945  Many aspects of the biology of Ericrocidini bees remain unclear and have been poorly studied.Detailed studies of the behavior of females and first instar larvae are still lacking.Although the phylogenetic relationships within Ericrocidini and among the subgenera of Centris are not well resolved, the current knowledge on host-parasite associations points to a relatively high degree of specificity and possible coevolution between them.
. The available host records indicate that these two genera are mainly associated with C. (Paracentris) and C. (Wagenknechtia) Moure, 1950, with Mesonychium also attacking C. (Centris).The records of females of M. asteria Smith, 1854 flying over nests of Epicharis nigrita (Friese, 1900) (GAGLIANONE 2005) and of Epicharis bicolor Smith, 1854 (ROCHA-FILHO et al. 2008) constitute only indirect evidence, and cannot be taken as confirming the association with Epicharis.
Mesoplia rufipes(Perty, 1833)that also parasitizes nests of Epicharis Klug, 1807.Although the phylogenetic relationships within Ericrocidini and among the subgenera of Centris are not well resolved, the current knowledge of the host-parasite associations points to a relatively high degree of specificity and possible coevo- Snelling & Brooks, 1985gia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de SãoPaulo.14040-901RibeirãoPreto,SãoPaulo,Brasil.o de Ciências da Natureza, Universidade Federal doAcre.Campus, 69915-900 Rio Branco, Acre, Brasil.rio de Biologia Comparada de Hymenoptera, Departamento de Zoologia, Universidade Federal doParaná.Caixa Postal 19020, 81531-980 Curitiba, Paraná, Brasil.esponding author.E-mail: garmelo@ufpr.brABSTRACT.For the first time, confirmed host records are reported for the monotypic Ericrocidini genus AglaomelissaSnelling & Brooks, 1985.Aglaomelissa duckei (Friese, 1906)emerged from trap-nests of Centris (Heterocentris) analis (Fabricius, 1804) and C. (Heterocentris) terminata Smith, 1874 from two sites in the Brazilian Amazonian region.The parasitism ratio caused by A. duckei was high, varying from 80 to 100% of the brood cells in a single trap-nest.Also, a compilation of the known host records for the species of Ericrocidini is presented and host-parasite associations are discussed.Host associations are known for seven of the 11 genera and about 17 of the 42 species of the tribe, involving a total of 34 confirmed or putative host species of Centridini bees.All species of the tribe are known to attack only nests of Centris Fabricius, 1804, except

Table I .
Characteristics and data from the nests of C. analis collected at Catuaba and Humaitá reserves, in Acre, and of C. terminata at two forest reserves, in Manaus, Brazil.The nests are indicated by their field identification codes.

Table II .
Known host associations for cleptoparasitic bees of the tribe Ericrocidini.

Table II .
Continued.