Population Traits and a Female Perspective for Aglae and Exaerete, Tropical Bee Parasites (Hymenoptera, Apinae: Euglossini)

Abstract

Size variation of both males and females leads to taxonomic confusion regarding wholly parasitic euglossines. The six most widespread species, Exaerete frontalis, E. smaragdina, E. dentata, E. trochanterica, E. lepeletieri, and Aglae caerulea, ranged from 12.5 to 28 mm in length (n = 522; 50 females; 472 males), and within species, some were 40-80% larger than others. The size of E. lepeletieri matches E. smaragdina and E. dentata, but not E. frontalis, which it was said to resemble. Female E. lepeletieri, here described from Amazonian Ecuador, has a range shown to also include French Guiana and Suriname. Female Aglae and Exaerete were larger than males. Statistically, female Exaerete tended toward larger individuals more than did males. Each species should parasitize Eulaema and Eufriesea that have comparable size and provisions; thus multiple hosts may cause parasite size variation. Unknown factors may promote host resource partitioning between sympatric parasites, which include up to six in Yasuní Biosphere Reserve, Ecuador, the richest known euglossine community. Scutellum and metafemur punctation, sculpture and the frontal knob of both sexes, and male mesotibial tuft and metafemur permit easy identification of the six common species and E. azteca. Existence of E. kimseyae in Panama is questionable, while E. dentata there is certainly rare. The female tibial scoop, a structure in both Aglae and Exaerete, with a proposed function in material transport, is discussed. No new phylogenetic interpretation is presented.

First Case of Gynandromorphism in the Orchid-Bee Eulaema meriana (Olivier) (Hymenoptera: Apidae)

“…This is due to the notable lack of knowledge of the Ecuadorian bee fauna. Although, in recent years, euglossines have been the relatively most studied group of this fauna, to the point that they are the only group that currently has a species checklist and several recent revisions (Botsch et al, 2017;Padrón et al, 2018;López, 2018;Yanouch et al, 2018;Suárez-Torres, 2019;Roubik, 2019).…”

Bees, Ecological Roles Bees: Ecological Roles

“…In addition, a significant minority of bee species (about 8-20% in a given biome) are nest and brood provision-parasites of their own or other species and function to depress bee populations. ▶ Orchid bees, for example, include two wholly parasitic genera, Exaerete and Aglae [10]. Evidently unlike the ▶ bumble bees, which in the genus Bombus have a parasitic subgenus ▶ Psithyrus, euglossines of the genus Euglossa often eat the eggs of competing females within nests, but have not evolved obligate parasitism or even castes, thus are not at the primitively ▶ eusocial level of the bumble bees.…”