Spatio-temporal variation of predatory hoverflies (Diptera: Syrphidae) and their relationship with aphids in organic horticultural crops in La Plata, Buenos Aires

Population variations of predatory hoverflies in agroecosystems depend mainly on the resources that crops and wild vegetation provides them as well as death caused by natural enemies. We identified I) aphidophagous hoverfly species in lettuce and broccoli crops in Buenos Aires, II) the seasonal variations of the immature stages and their larval parasitism, and III) the wild plants, surrounding the crops, visited by adults. Fortnightly, 30 leaves were randomly selected in both crops during 2018-2019 and immature stages of syrphids and aphids per leaf were recorded. Adults were manually collected in patches of the wild plants (during 10 min of direct observations), and plants visited by adults were determined. The hoverflies were Allograpta exotica Wiedemann and Toxomerus duplicatus Wiedemann. Only A. exotica was recorded in crops. The dominant aphids were Myzus persicae (Sulzer) in lettuce and Brevycorine brassicae (L.) in broccoli. Parasitism rates ranged between 8 and 100% and the species were Diplazon laetatorius (Fabricius), in both crops, and Pachyneuron aff. nelsoni only in broccoli. Galinsoga parviflora Cav. and Matricaria chamomilla L. were the wild plants most often visited by hoverflies. This work provides basic information for the control of aphids by hoverflies in the framework of conservation biological control

New species and records of Ichneumonidae (Hymenoptera)

Temelucha xana sp. n. is described from Spain. First records of Campoletis crassicornis (Tschek, 1871) from Algeria and Western Sahara, Campoletis katalinarum Vas, 2019 from Syria, Campoletis vimmeri (Gregor, 1938) from Albania, Dusona leptogaster (Holmgren, 1860) from Hungary, Meloboris collector (Thunberg, 1822) from Morocco and Rwanda, Nemeritis macrocentra (Gravenhorst, 1829) from Montenegro, Nepiesta tibialis Horstmann, 1977 from Greece, Temelucha annulata (Szépligeti, 1899) from North Macedonia, Temelucha caudata (Szépligeti, 1899) from Armenia and North Macedonia, Temelucha cylindrator Narolsky, 1987 from Greece, Temelucha decorata (Gravenhorst, 1829) from Armenia, Temelucha genalis (Szépligeti, 1899) from North Macedonia, Temelucha lucida (Szépligeti, 1899) and Temelucha minuta (Morley, 1912) from Spain, Temelucha variipes (Szépligeti, 1899) from North Macedonia, Diplazon laetatorius (Fabricius, 1781) from Western Sahara, Homotropus elegans (Gravenhorst, 1829) from Morocco and Western Sahara, Enicospilus glabratus (Say, 1835) from Martinique, and Thyreodon rufothorax Cameron, 1886 from French Guiana are reported. With one figure.

Parasitoids of Heterogynis Rambur (Lepidoptera: Zygaenoidea, Heterogynidae)

Nine parasitoids of the moth genus Heterogynis are presented: six species of Hymenoptera from the families Chalcididae, Eulophidae and Ichneumonidae (Agrothereutes hospes (Tschek), Baryscapus endemus (Walker), Brachymeria inermis (Fonscolombe), Diplazon laetatorius (F.), Itoplectis maculator (F.) and Trichomalopsis heterogynidis Graham), and three Diptera, family Tachinidae (Compsilura concinnata (Meigen), Exorista segregata (Rondani) and Phryxe hirta (Bigot)). Two of these species, Trichomalopsis heterogynidis and Phryxe hirta, are oligophagous parasitoids specialized on the genus Heterogynis. We also identified two newly recorded parasitoids of Heterogynis: Brachymeria inermis (Chalcididae) and Diplazon laetatorius (Ichneumonidae).