124 



Pachyneuron coccorum, L,, is widespread in. Europe and probably 

 has been introduced into America with European scales In Italy 

 it occurs wherever the scales harbouring its victims are found. It 

 parasitises the Dipteron, Leucopis sp., infesting Filippia oleae, 

 and also parasitises the following Chalcids : Blastothrix sericea and 

 Aphycus punctipes, infesting Eulecanium coryli ; Microterys lunatus, 

 Mayr, and Phaenodiscus aeneus, infesting S. prunastri ; and Microterys 

 niasii, Silv., infesting Filippia oleae. It hibernates in the larval 

 stage, and may perhaps also do so as an adult. Pupation occurs in 

 April and the adult appears in May. The adult feeds on sugary 

 substances and begins ovipositing 2 or 3 days after emergence. The 

 complete life-cycle took 27 days in May for individuals bred from 

 Aphycus punctipes, 20 days in June from Leucopis sp., and 21 days in 

 September from Phaenodiscus aeneus. Females of S. prunastri 

 yield from 1 to 5 of these hyper-parasites and those of Eulecanium 

 coryli from 1 to 10. Pachyneuron coccorum has at least 5 generations 

 from May to September. In a case observed in 1918 about two-thirds 

 of the primary parasites in Eulecanium coryli were destroyed. This 

 was an isolated instance, and in 1919 the parasitism of Phaenodiscus 

 aeneus infesting S. prunastri only amounted to 3 per cent. 



Perrisopterus zebra, Kurdj., has been obtained by the author only 

 from S. prunastri on Prunus spinosa. It is a ectoparasite of Phaeno- 

 discus aeneus infesting S. prunastri, of which it therefore is a secondary 

 or tertiary parasite. The larva of this hyper- para.site appears at 

 Portici in the first fortnight of September, in less than 2 days after 

 oviposition. Five days afterwards pupation takes place, and the 

 entire life-cycle from egg to adult requires 12 days. Microterys lunatus, 

 Dalm., probably occurs throughout Europe. The adults were seen 

 emerging from S. prunastri in June. 



SiLVESTRi (F.). Contribuzioni alia Conoscenza degli Insetti dannosi e 

 dei loro Simbionti. V. La Cocciniglia del Nocciuolo (Eulecanium, 

 coryli, L). [Contributions to the Knowledge of Injurious 

 Insects and of their Associates, v. The Hazel-Nut Scale, 

 E. coryli.]^Boll. Lab. Zool. Gen. Agrar. R. Scuola Sup. Aqric, 

 Portici, xiii, 1919, pp. 127-192, 34 figs. [Received 17th Januarv 

 1920.] 



A fuU description and synonymy are given of Eulecanium coryli, L., 

 which is widely distributed in Europe, and according to King, also 

 occurs in North America. E. capreae, L., is included among the 

 synonyms. In Italy the author has found it on Corylus avellana, 

 pear, apple, Prunus domestica, P. spinosa, Acer campestris, JJlmus 

 campestris, Crataegus oxyacantha, C. azarolus, Salix vitellina, and 

 Carpinus betulus. Many other food-plants have been recorded, 

 including Rosa sp., Cydonia vidgaris, Prunus armeniaca, Crataegus 

 pyracantha, C. coccinea, Quercus suber, Acer pseudoplatanus, Acer 

 platanoides, Cornus sanguinea, Tilia sp., Juglans regia, Aesculus 

 hippocastanum, Popuhis virginiana, Cotoneaster sp., Prunus lauro- 

 c^rasns, P. cerasus, Euonymus sp., Vaccinium myrtillus, Rubus sp., 

 and Myrica gale. 



At Portici o\'iposition begins at the end of March ; at higher altitudes 

 such as 3,300 feet, it is delayed about 2 months. As many as 4,905 



