Beedrill #015
Face of a southern yellowjacket (Vespula squamosa)
Opo Terser (CC BY 2.0)
The order Hymenoptera comprises ants, bees, and wasps.
An evolutionary strategy known as parasitoidism evolved once in Hymenoptera (Zhang et al. 2020). Parasitoids use an ovipositor, a needle-like organ, to inject eggs into live or paralyzed hosts where the larvae will develop as parasites.
The stinger evolved as a modified ovipositor (Shing and Erickson 1982) to inject venom into a target. Wasps are able to pierce the victim multiple times. When the nest of a eusocial species is under attack, they may swarm, delivering an increasing dose of neurotoxins and other chemicals with each successive sting. Eusociality is defined by a colony with castes, or a division of labor. There is a queen, drones, soldiers, and workers. Most wasps are solitary.
Potter wasp building a mud nest
Ian Alexander (CC BY-SA 4.0)
Cooperative brood care in honeybees
Tenan (CC BY-SA 3.0)
Eusociality is determined by a system of genetics and reproduction. In a haplodiploidy system, females have two sets of chromosomes while males have just one. Haplodiploidy applies to all Hymenoptera and results in female hive workers that are highly genetically related, providing a strong incentive for cooperation. Unfertilized eggs develop into males, or drones.
Shing, H.; Erickson, E. H. (1982). "Some ultrastructure of the honeybee (Apis mellifera L.) sting". Apidologie. 13 (3): 203–213.
Zhang, Qi; Kopylov, Dmitry S.; Rasnitsyn, Alexandr P.; Zheng, Yan; Zhang, Haichun (November 2020). Smith, Andrew (ed.). "Burmorussidae, a new family of parasitic wasps (Insecta, Hymenoptera) from mid-Cretaceous Burmese amber". Papers in Palaeontology. 6 (4): 593–603.