Ormyrus diffinis (Fonscolombe, 1832)

Gomez, Jose F., Nieves, Maria Hernandez, Gayubo, Severiano F. & Nieves-Aldrey, Jose Luis, 2017, Terminal-instar larval systematics and biology of west European species of Ormyridae associated with insect galls (Hymenoptera, Chalcidoidea), ZooKeys 644, pp. 51-88 : 59

Ormyrus diffinis (Fonscolombe, 1832)

Material examined.

ex gall Liposthenes kerneri (Wachtl) on Nepeta hispanica Spain, Madrid: Casa Eulogio, 01.VI.03, J. L. Nieves leg (n = 8); Madrid: Rivas-Vaciamadrid, 01.VI.03, J. L. Nieves leg (n = 5); Madrid: Rivas-Vaciamadrid, 13.VI.03, J. L. Nieves leg (n = 1); Madrid: Rivas-Vaciamadrid, 17.V.03, J. L. Nieves leg (n = 22)

Description.

n = 36; Body length: 1.56 ± 0.34 mm (min-max: 1.00-2.40 mm), width: 0.83 ± 0.12 mm (min-max: 0.60-1.00 mm). Body fusiform, not tapering abruptly towards anal segment (Figs 3C, 5C) (Table 2); adp present from second thoracic to fifth abdominal segment protruding beyond the dorsal margin of body in lateral view (Fig. 5C); integument smooth; thoracic setae relatively long, abdominal setae shorter. Head 1.12 times wider than high (Fig. 7C); integument of genal area with blister-like sculpture; vam more separated than distance SA; am situated slightly above antennae (Table 2).

On clypeus lcs situated at the same level of cs; lateral lobes of labrum strongly remarked and incompletely fused with the medial lobe; posterior margin of medial piece of labrum convex (Fig. 9C); mandible unidentate with the apex slightly visible under lb; tooth acute (Fig. 11B).

Biology.

The species is a common parasitoid reared from cynipid galls of Liposthenes kerneri (Wachtl) on fruits of Nepeta ssp. ( Lamiaceae ; Fig. 12I) ( Askew et al. 2006). Full-growth larva of Ormyrus diffinis occupied the entire primary cell of a parasitized gall after the host larvae was devoured (Fig. 12J and K). We observed that larvae of Ormyrus diffinis inside galls apparently entered prolonged periods of diapause, without causing normal pupation and adult emergence after the winter diapause period. Moreover, live terminal-instar larvae of Ormyrus diffinis were found in galls dissected two years after collection. The data indicate that Ormyrus diffinis is an idiobiont ectoparasitoid with a univoltine life cycle that is synchronized with the emergence and growth of their host galls on species of Nepeta . The insects emerge in the second year when the new galls are available again on the host plant. This species has also been reared from galls of Neaylax salviae and Neaylax nemorosae on different species of Salvia ( Lamiaceae ) and from those of Rhodus cyprius on Salvia triloba ( Lamiaceae ) ( Askew et al. 2006).