DOI: 10.3897/contrib.entomol.76.e189240

Authors: Marco Chan, Matthew T. Hamer, Benoit Guénard

Abstract: Orthonotomyrmex Ashmead, 1906 is one of the most morphologically distinct subgenera in the genus Camponotus Mayr, 1861 with a marginated propodeum, nodiform petiole and punctate sculpturing covering most of the body. Here, we propose a new species complex native to Southeast Asia, the Camponotus selene–complex. We also propose the elevation of Camponotus obtusatus (Emery, 1895) as a valid species, the synonymisation of C. lasiselene syn. nov. with C. obtusatus and describe a new species, Camponotus orthogonius sp. nov. from Hong Kong SAR. The type series was collected within multiple neighbouring twigs from a singular fallen tree suggesting a polydomic colony structure. Keys to the known species of the selene–complex are provided for both minor and major workers. We also provide new distribution data for Camponotus obtusatus stat. nov. and Camponotus siamensis Jaitrong & Jeenthong, 2022 from Fujan Province, China and Laos, respectively. The proposal of the new selene–complex serves to facilitate future revisions Orthonotomyrmex when more Afrotropical specimens are available to better diagnose the subgenus. The discovery of C. orthogonius sp. nov., alongside newly–reported range extensions, reinforces the potential of further arboreal ant species discoveries in Southeast Asia.

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DOI: 10.3897/contrib.entomol.75.e144856

Authors: D. Christian Furness, Elaine Tan, John T. Longino

Abstract: Temperate zone ants overwinter using a variety of mechanisms. The genus Formica overwinters entirely as adults. In at least one species it has been demonstrated that winter workers are more corpulent than summer foragers, storing resources in their bodies and mobilizing them for early brood production in spring. Here we examine overwintering by the common western thatch ant, F. obscuripes. Excavation of a winter nest revealed only workers, distributed in multiple chambers in a roughly spherical region from 0.5 to 1.05 m deep. Worker size, as measured by head width, was weakly bimodal, with fewer workers in the small vs. large size class. We measured dry weights of workers from the winter nest and workers collected the previous summer from the surfaces of multiple nests in the vicinity, including our excavated nest. Controlling for size, there was no evidence of bimodality in winter worker weight, and winter workers were 59.7% heavier than summer foragers. These results suggest that F. obscuripes workers are at their maximum corpulence going into their first winter, expend their stored fat during spring, and mostly die before overwintering a second time. It remains uncertain whether workers can regain corpulence.

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DOI: 10.3897/contrib.entomol.75.e142567

Authors: Javier Arcos, Elías Amorós, Ángel Rosado, Paco Alarcón

Abstract: The little fire ant (Wasmannia auropunctata), notable for its minute size and painful sting, has emerged as a significant threat in Mediterranean Europe. This widespread exotic species is well-known because of its invasive nature, impacting biodiversity, public health, and economic activities. Noted for the first time in Málaga (S Spain) in 2018, it has since expanded to other locations in the same province. Here we report the presence of W. auropunctata in La Marina (Alacant province, SE Spain), representing the fifth recorded population on the Iberian Peninsula and the first occurrence outside Málaga province. The species was found infesting a coastal area of approximately 5.1 hectares, with workers being observed in foraging trails across multiple surfaces and living in dense concentrations both indoors and outdoors. Exclusion of native ant species within the occupied area and direct engagement in combat with other species was observed. The population was discovered in September 2024; however, based on infestation density, spatial extent, and comparison with data of other Mediterranean exotic populations, the species likely established in the region prior to 2019. For the first time in Iberia, W. auropunctata was also detected in the coastal dunes adjacent to the infested urbanised area, highlighting its potential adaptability to dry Mediterranean habitats. The resilience of W. auropunctata, combined with its aggressive invasive traits and propensity to sting, underscores the urgent need for integrated management strategies to limit further expansion of the species in Iberia.

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