Indoor Occurrence of the Ghost Ant Tapinoma melanocephalum (Hymenoptera: Formicidae) in Urban Homes in Korea

The ghost ant Tapinoma melanocephalum is a common household pest worldwide. The present study examined the occurrence of the species in urban homes in Korea. During the period of September 2014 to January 2016, T. melanocephalum workers were collected from 58 homes at 29 different localities using bait traps with 10% sugar solution. The species was widely distributed throughout urban homes at 29 different localities, and the indoor occurrence of T. melanocephalum was highest in Seoul (32.7%) and metropolitan areas of Gyeonggi-do (Province) (29.3%). The indoor incidence rate of T. melanocephalum peaked in September (22.8%), remained moderate from October through April, and peaked again in May (15.7%). In contrast, a low incidence was observed from June to August (7.0%). The present study provides evidence that native ants, such as T. melanocephalum, are potential indoor pests of homes in Korea throughout the year.

Urban ants and transportation of nosocomial bacteria

Many ant species displaying synanthropic behavior that have successfully dispersed in urban areas can cause problems in hospitals by acting as bacterial vectors. In this study, we encountered bacteria on ants collected at the Universidade Federal de Uberlândia hospital, in the campus and at households nearby. The ants were identified as Tapinoma melanocephalum (Fabricius) and Camponotus vittatus (Forel) (Hymenoptera: Formicidae) and the bacterial strains found here belong to the group of the coagulase-positive staphylococcus, coagulase-negative staphylococcus and gram negative bacilli, including antimicrobial drug-resistant strains. An investigation of the bacteria found in the ants and in the environment revealed that some ants carried non-isolated bacteria from the same environment and with high levels of resistance, evidencing the transmission potential of these insects.

Muitas espécies de formigas de comportamento sinantrópico que tiveram sucesso na dispersão em áreas urbanas podem causar problemas em hospitais ao atuarem como vetoras, transportando bactérias. Neste estudo, foram encontradas bactérias em formigas coletadas no Hospital de Clínicas da Universidade Federal de Uberlândia, no campus e em residências próximas. As formigas coletadas foram identificadas como Tapinoma melanocephalum (Fabricius) e Camponotus vittatus (Forel) (Hymenoptera: Formicidae) e as cepas bacterianas encontradas pertenciam ao grupo dos estafilococos coagulase positivos, estafilococos coagulase negativos e bacilos gram negativos, tendo sido encontradas cepas resistentes a antimicrobianos. O estudo de bactérias encontradas nas formigas e no ambiente mostrou que algumas formigas carreavam bactérias não isoladas do mesmo ambiente e com níveis de resistência mais elevados, evidenciando o potencial transmissor desses insetos.

Efectos de Tapinoma melanocephalum (Hymenoptera: Formicidae) sobre huevos de Aedes aegypti (Diptera: Culicidae) en insectario / Effects of Tapinoma melanocephalum (Hymenoptera: Formicidae) on Aedes aegypti (Díptera: Culicidae) eggs in an insectarium

Se evaluó por primera vez en Cuba la acción de Tapinoma melanocephalum, una especie de hormiga causante de daños en cultivos agrícolas, en un insectario de Entomología Médica sobre las puestas de huevos de Aedes (Stegomyia) aegypti en las colonias de crías y en el lugar de almacenamiento. La colonia de hormigas procedía de una población natural estudiada que se estableció en el insectario. Los huevos respondían a 2 épocas de oviposición distintas (recién puestos entre las 24 h y almacenados durante 8 meses). Los resultados obtenidos mostraron una mayor depredación de T. melanocephalum sobre los huevos de Aedes aegypti recién puestos (Z= 9,1; p< 0,0001) .La acción depredadora de Tapinoma melanocephalum sobre las puestas de huevos de Aedes aegypti, se debe tener en cuenta en la colonización de este mosquito.

The action of Tapinoma melanocephalum, an ant species causing damages to agriculture, on Aedes (Stegomyia) aegypti eggs was evaluated for the first time in Cuba at an insectarium of Medical Entomology in the breeding colonies and the storage place. The ants colony came from a studied natural population established inside the insectarium. Eggs belonged to two different oviposition times: (a) laid within the previous 24 h. and (b) stored in the lab for 8 months. The results obtained showed a higher predation of T. melanocephalum over the newly laid Aedes aegypti eggs (Z=9.1; p <0.0001). The predating action of Tapinoma melanocephalum on Aedes aegypti eggs should be considered in the colonization of this mosquito.