Arthropods Daily – Issue No. 224

The grass-carrying wasp Isodontia mexicana (Saussure) exhibits interesting behaviors related to sex allocation, nest construction, and prey selection. Females of this species exhibit facultative sex allocation, meaning they can adjust the sex ratio of their offspring depending on certain factors. The wasps construct nests from grass stems, lining them with glandular secretions for protection against pathogens. They also provision their nests with paralyzed insects as food for their developing offspring. The effects of brood parasitism on Isodontia mexicana have been studied, revealing that it can have sublethal effects on the wasps' reproduction and survival. In some regions, the species has been introduced adventitiously, like in Piedmont, Italy.