Hidden biodiversity in entomological collections: The overlooked co-occurrence of dipteran and hymenopteran ant parasitoids in stored biological material

Abstract

Biological collections around the world are the repository of biodiversity on Earth; they also hold a large quantity of unsorted, unidentified, or misidentified material and can house behavioral information on species that are difficult to access or no longer available to science. Among the unsorted, alcohol-preserved material stored in the Formicidae Collection of the ‘El Colegio de la Frontera Sur’ Research Center (Chetumal, Mexico), we found nine colonies of the ponerine ant Neoponera villosa, that had been collected in bromeliads at Calakmul (Campeche, Mexico) in 1999. Ants and their brood were revised for the presence of any sign of parasitism. Cocoons were dissected and their content examined under a stereomicroscope. Six N. villosa prepupae had been attacked by the ectoparasitoid syrphid fly Hypselosyrphus trigonus Hull (Syrphidae: Microdontinae), to date the only known dipteran species of the Microdontinae with a parasitoid lifestyle. In addition, six male pupae from three colonies contained gregarious endoparasitoid wasps. These were specialized in parasitizing this specific host caste as no gyne or worker pupae displayed signs of having been attacked. Only immature stages (larvae and pupae) of the wasp could be obtained. Due to the long storage period, DNA amplification failed; however, based on biological and morphological data, pupae were placed in the Encyrtidae family. This is the first record of an encyrtid wasp parasitizing N. villosa, and the second example of an encyrtid as a primary parasitoid of ants. Furthermore, it is also the first record of co-occurrence of a dipteran ectoparasitoid and a hymenopteran endoparasitoid living in sympatry within the same population of host ants. Our findings highlight the importance of biological collections as reservoirs of hidden biodiversity, not only at the taxonomic level, but also at the behavioral level, revealing complex living networks. They also highlight the need for funding in order to carry out biodiversity inventories and manage existing collections.

Nest Site Selection during Colony Relocation in Yucatan Peninsula Populations of the Ponerine Ants Neoponera villosa (Hymenoptera: Formicidae)

“…Due to their morphological similarity, N. villosa has been confused in the past with two other species with a wide distribution, N. inversa (Smith) and N. curvinodis (Forel). Until now, however, only N. villosa has been reported in the Yucatan Peninsula [58]. Nevertheless, in order to confirm ant identity and further support our comparisons, five workers nesting in bromeliads and five workers nesting in live trees were DNA extracted and barcoded as part of an independent study (Lachaud and Pérez-Lachaud, unpubl.).…”

Context dependent life-history shift in Macrodinychus sellnicki mites attacking a native ant host in Colombia

“…As in other very specific ant parasitoids such as encyrtid and eucharitid wasps or phorid and syrphid flies 38–41 , prevalence of parasitism by M . sellnicki upon Ectatomma sp.…”

“…These behavioral traits may favor spread of the mites among nests. However, as with many other associations involving very tiny organisms, especially those hidden within a cocoon 41,47 , it is also possible that these symbiotic associations had been quite simply overlooked. More data are needed about the specificity of the Macrodinychus / Ectatomma association, the temporal distribution of mites in Ectatomma nests, and the behavioral interactions with their host ants (if any).…”

A case of silent invasion: Citizen science confirms the presence of Harmonia axyridis (Coleoptera, Coccinellidae) in Central America

“…Natural history collections harbor billions of specimens of which many are associated with taxonomic, geographic, and temporal data. These collections are an important asset in the study of the world’s past and current biodiversity, to understand changing parasite–host dynamics, reconstruct evolutionary history of infectious agents, provide data on phenological changes of organisms in response to climate change, identify unknown specimens and discover undescribed species, determine when pests, pathogens, or vectors are introduced, etcetera [49,50,51,52,53]. All too often, natural history collections are only accessible by researchers of the institutions where they are housed [54], resulting in significantly understudied collections [55] and an estimated average “shelf life”–the time between discovery and description of a new species–of 21 years [56].…”