Cerroneuroterus lanuginosus ( Giraud, 1859 ), 2018

Shachar, Einat, Melika, George, Inbar, Moshe & Dorchin, Netta, 2018, The oak gall wasps of Israel (Hymenoptera, Cynipidae, Cynipini) - diversity, distribution and life history, Zootaxa 4521 (4), pp. 451-498 : 471-472

Cerroneuroterus lanuginosus ( Giraud, 1859)

Cerroneuroterus cerrifloralis (Müllner) , new synonym.

Host plants. Israel: Q. ithaburensis . Elsewhere: several oak species from section Cerris.

Life history. The sexual and asexual generations of this species are associated with each other for the first time in the present study. The sexual generation induces inconspicuous, spherical catkin galls, 1.5–2 mm in diameter, green when young, turning brown when mature, covered by white hairs ( Fig. 54 ). The galls are single-chambered and the chamber fills the entire volume of the gall. The asexual generation induces flat, circular leaf galls, up to 7 mm in diameter and 5 mm thick, densely covered by long, white to golden hairs with a black center of shorter hairs ( Figs 60–61 ). These are probably the most abundant cynipid galls in Israel, which often cover the entire leaf surface; a single tree can bear tens of thousands of galls, although gall density may vary dramatically between years and trees.

Phenology. Galls of the sexual generation appear in early February and adults emerge from them in late February. Galls of the asexual generation begin to develop in August, drop from the leaf or together with the leaves in fall, and the wasps overwinter in them as pupae or adults. Adults emerge in January.

Distribution. Israel: Very common and widespread throughout the distribution range of Q. ithaburensis . Elsewhere: A common species from South-central Europe to Transcaucasia and Iran.

Comments. The sexual generation is known from Austria and Hungary, and although adults in Europe and in Israel are slightly different morphologically, we consider them to belong to the same species. Sternlicht (1968b) attributed the galls of this species to the sexual generation of Neuroterus aprilinus Giraud (currently a synonym of Neuroterus politus Hartig (Pujade-Villar & Ros-Farré 2001)) . However, the galls of C. lanuginosus are covered by white hairs and are thin walled, whereas those of N. politus are smooth with a fleshy wall when young, turning thick when mature.

Galls of the asexual generation are similar to galls induced by an unidentified cecidomyiid species on the same host plant but the cecidomyiid galls are brownish-white and are evident as rigid tubercles on the upper side of the leaf, whereas the galls of C. lanuginosus are usually white and are evident only on the underside of the leaf.

Galls of the sexual generation of this species have been attributed so far to C. cerrifloralis but molecular work shows that they actually belong to C. lanuginosus (Shachar, unpublished data), therefore we synonymize C. cerrifloralis under C. lanuginosus and the species is now known from both generations.

Figures

FIGURES 53–58. Galls on Quercus ithaburensis. 53. Pseudoneuroterus sp. 2, sexual generation; 54. Cerroneuroterus lanuginosus, sexual generation; 55. Pseudoneuroterus macropterus, sexual generation; 56. Pseudoneuroterus sp. 1, sexual generation; 57. Pseudoneuroterus saliens, sexual generation; 58. Pseudoneuroterus saliens, asexual generation.

FIGURES 59–64. Galls on Quercus ithaburensis. 59. Chilaspis israeli, asexual generation; 60–61. Cerroneuroterus lanuginosus, asexual generation; 62. Cerroneuroterus gyulaigaraiae, asexual generation; 63. Andricus sp. nr. istvani, sexual generation; 64. Dryocosmus mikoi, sexual generation.