Andricus caputmedusae ( Hartig, 1843 )

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 : 459-460

Andricus caputmedusae ( Hartig, 1843)

Host plants. Israel: Q. boissieri . Europe: common on Q. petraea and Q. pubescens , occasionally on Q. robur and Q. frainetto , Q. dalechampii and Q. hartwissiana . Greece, Turkey and Iran: Q. infectoria .

Life history. Known only from the bud galls of the asexual generation. Molecular data suggest that the sexual generation of this species develops in cryptic bud galls currently attributed to the A. burgundus complex or to A. atkinsonae Melika, Stone, Sadeghi & Zargaran, 2008 (as in Fig. 52 ) ( Stone et al. 2008; Tavakoli et al. 2008). The gall of the asexual generation occupies the acorn and acorn cup, covering the entire surface of the acorn. Young galls consist of a circle of petal-like spines radiating from a young acorn cup. The fully developed spines in a mature gall originate as small bumps within this circle, gradually developing into long, twisted spines that are often branched, and reach 30 mm in length. Individual galls may reach 6 cm in diameter and are single-chambered, but aggregations of several galls may form a multi-chambered mass reaching 10 cm in diameter. Young galls are bright pink and coated by sticky resin ( Fig. 7 ), whereas mature galls are light brown and not sticky ( Fig. 8 ). Some of the galls drop from the tree in fall and mature on the ground, whereas others remain on the tree after adult emergence and become black.

Phenology. Galls become apparent in July and mature in the fall. Some adults emerge in late September-early October, while others emerge in February and March. A few enter diapause and emerge in the following year.

Distribution. Israel: Mt. Hermon, 1500 and 1780 m.a.s.l., Mt. Kahal. Elsewhere: Widespread from Northern Europe to Iran.

Comments. The galls of this species resemble galls of the asexual generation of A. cecconii on the same oak host ( Fig. 6 ) (previously known as A. megalucidus Melika, Stone, Sadeghi & Pujade-Villar , synonymized in the present paper) but differ from them in the branching, irregular, harder and more pointed spines, and in containing a single larval chamber, whereas galls of A. cecconii are multi-chambered.

Figures

FIGURES 47–52. Sexual generation galls on Quercus ithaburensis. 47. Andricus cecconii; 48. Same, old gall; 49. Andricus grossulariae, young galls; 50. Andricus grossulariae, old galls (arrow); 51. Andricus vindobonensis; 52. Andricus coriarius.

FIGURES 5–10. Galls on Quercus boissieri. 5. Andricus lucidus, asexual generation (arrow) and Andricus moreae, asexual generation (bottom); 6. Andricus cecconii, asexual generation; 7. Andricus caputmedusae, asexual generation, young gall; 8. Andricus caputmedusae, asexual generation, mature gall; 9. Andricus grossulariae, asexual generation; 10. Andricus hystrix, asexual generation.