AXD CONTROL 



MEANS OF PREVENTION AND CONTROL 1 22 1 



The following particulars of yields were also obtained : 



Weight of 100 ears 

 \'arieties of Wheat Number of ears Weight — 



— — — gr. 



" Fulcaster " 37i 334 90.30 



" Fultz " 439 324 73-8o 



Indigenous contiul 367 273 74-38 



According to the analyses hitherto carried out, a relation between the 

 degree of immunity and the ash content appears to be outlined : 



% of ash % of ash 



Varieties of Wheat iu young plants in straw 



"Fultz" 15-146 5-14/ 



"Fulcastu" 15-379 4598 



Indigenous 14.796 4-751 



The degree of infestation in the three varieties appears to var}^ in 

 direct proportion to the ash content. 



948 - Aspidiot/phag-us ciirinus, Endo parasite on Chrysomphalus die- means 



tyospermi in Italy. — :Malenotti Ettore in L'Agncoltum ttaliana, Ilud Year O F prevention: 

 (Vth series), pp. 73-75. risa, May-Jtuie 1916. , 



While collecting Coccidae on plants cultivated under glass at Florence, 

 the writer observed a case of parasitism of Aspidiotiphagus citrinus (Craw.) 

 How. on Chrysomphalus dictyospermi (Morg.) lyCon. 



This endoparasite, which often hatches from Aspidiotus hederae, A. 

 behdae and man}- other species of diaspids, had only been reported previously 

 as a parasite of C. dictyospermi in one single case, namely by H. E. HODG- 

 KISS, at Cromwell, Connecticut, on hot-house palms. 



The degree of parasitism of Chrysomphalus by A. citrinus was ver>' 

 great. Of 121 females observed on two leaves, there were 21 which had 

 died naturalh', 97 parasitised, and 3 free. On other leaves of the same plant 

 the coccids were likewise parasitised in large proportions. 



The observations made now allow of establishing clearly the differences 

 between the behaviour of A . citrinus as compared with A . lounsburyi Berl. 

 and Paoli on the same host. These differences are due in part to the dimen- 

 sions of the adults of the two parasites which are markedly smaller in the case 

 of A . lounsburyi, and in part again by the different pathological action they 

 exercise on their -victims. 



Chrysomphalus dictyospermi, .so strongl}- attacked by A. citrinus, 

 was gathered by the Author on leaves of Sansevieria arborescens imported 

 from the Natural History Museum of Paris. The species originates from 

 tropical Africa and the East Indies. 



The writer was unable to ascertain whether C. dictyospermi, which, 

 according to the supervising staff, has always been seen on Sansevieria, 

 brought its parasite with it, or whether the latter arises from the Italian 

 form which adapted itself to the imported coccid. In the hot houses of 

 Florence examined by the writer Chrysomphcdus is not found on citrus 



