Nesting habits of two spider wasps:Anoplius infuscatusandEpisyronsp. (Hymenoptera: Pompilidae), with a review of the literature

Abstract

Abstract. Many behavioural aspects of Anoplius infuscatus (Vander Linden) and Episyron sp. Schioedte were examined in detail, both on a qualitative and, when possible, on a quantitative level, during a long-term fi eld study in Northern Italy. Both wasps dig unicellular nests on bare soil, which are fi lled with a single spider to feed the brood. The main differences regard the way to hunt their prey, that of burrowing, that of transporting and introducing the spider into the nest, the habit of amputating spider legs and the abdominal movements during nest closing. On the whole, starting from prey capture to nest closure, A. infuscatus is signifi cantly slower than Episyron. The observed ethological differences are well fi tted to the exploitation of the different preys consisting in wolf spiders (Lycosidae) and orb weaving spiders (Araneidae), respectively. Some fl exibility in the observed behaviour is described. A critical re-examination of the literature shows that, even if most results agree with those of previous authors, two controversial points remain open regarding Episyron species: the position of the egg (on the prey or on the cell wall) and the way to grasp the spider during tranport and introdution into the nest. Les deux pompiles creuvent des nids unicellulaires sur le sol nu, avec une seule araignée pour nourrir le couvain. Les principales différences concernent la manière dont ils chassent, dont ils creusent, dont ils transportent et introduisent la proie dans le nid, dont ils amputent les pattes de l'araignée ainsi que les mouvements abdominaux lors de la fermeture du nid. Dans l'ensemble, en partant de la capture jusqu'à la fermeture du nid, A. infuscatus est signifi cativement plus lent qu'Episyron. Les différences éthologiques observées sont bien adaptées à l'exploitation des différentes proies, des lycoses (Lycosidae) et les Araneïdes (Araneidae), respectivement. On observe une certaine fl exibilité dans les comportements observés. Un réexamen critique de la littérature montre que, même si la plupart des résultats sont conformes à ceux des auteurs précédents, deux controverses subsistent à propos des espèces d'Episyron : la position de l'oeuf (sur la proie ou sur la paroide la cellule), et la manière d'agripper la proie pendant son transport et son dépôt dans le nid.

Nest Characteristic Features and Prey Selection of Mud Dauber Wasp Sceliphron madraspatanum “Fabricius, 1781”

“…Similar results were observed by the previous studies in Anoplius infuscatus and Episyron sp. [18]. Camillo [7] also studied Sceliphron fistularium nest characteristics and notice the cells numbers in each nest ranging from 1 to 54, their length ranging from 20.8 to 29.7 mm, and their diameter ranging from 7.6 to 11.7 mm.…”

The benefits of grouping as a main driver of social evolution in a halictine bee

“…Many solitary wasps (with RA) have a similar lifestyle with halictid bees (making a nest with several brood chambers to which collected preys are stuffed with an egg). However, most of them leave the nest before the emergence of adult offspring although they are multivoltine ( 37 , 38 ). This habit deprives a daughter of the chance to choose to coreproduce with her mother.…”