1722 INSECT PESTS. - MEANS OF PREVENTION AND CONTROL 



160 apliids. The time occupied by the pupal stage varies according to 

 the season ; in March it lasts from 14 to 23 days, the average time being 

 16 daj^s, and in November the limits are the same but the average is 20. 



This species of Chrvsopa has six generations annually ; the first 

 from February 15 to ]\Iarch 15, and the others following on at intervals 

 of 40 to 45 days until late into the autumn. 



This insect is common and widel}' distributed in the States bordering 

 on the Pacific, Texas, Arizona, New-Mexico, Nevada, southern California, 

 and possibly in Utah. Among its natural enemies the chief are the western 

 wood peewee [Coniopiis richardsonii) and the nighthawk {Chordeiles virgi- 

 nianiis). 



i2^S -Signiphora merceti n. sp., a Natural Enemy of the Cochineal Insect 

 Chrysomphalus dictyospermi in Spain (i). —malenotti, e., in Redia, 



\'o\. XII, >7o. I, pp. 181-182. Florence, September 21, 1916. 



A s^'stematic description of a new Chalcid, Signiphora merceti, obtain 

 ed b}' breeding specimens of Chrysomphalus dictyospermi from Spain. 



Three females of this Chalcid have beene xamined, but the male is still 

 unknown. The new species is named after merckt the entomologist. 



1246 -Observations upon Icerya purchasi and its Natural Enemy Novius 



CSLfdinRlis in Sicily (2). — DeGregorio, A.,in // KatuvaUsta Siciliano, Vol. XXIII, 

 X. xS., Xos. 1-6, pp. 5-17, PI. I-IV. Palermo, 1916. 



Icerya purchasi Mask, has recently been found at Villabate (Palermo) 

 and the writer has been able to follow out the various stages in its develop- 

 ment. 



The larvae are able to move with great force and rapidity-, and more- 

 over the}- can be kept alive for several days without food. 



The writer confirms the statement that Novius cardinalis Muls. is 

 very useful in keeping down the numbers of Icerya. He introduced speci- 

 mens of Novius at Villabate which had been received from the Zoologi- 

 cal Laboratory at Portici (Naples). Other specimens had previously been 

 introduced at Bagheria (Palermo), and the writer believes that they had 

 multiplied with great rapidity and had helped on the destruction of the 

 cochineal insects at Villabate. He also thinks it probable that another of 

 the Coleoptera, Chilocorus hipustulatus L., is useful in the same way and 

 has also helped to stamp out Icerya at Villabate. The development of No- 

 vius is described in this paper. The statement that the adults feed upon 

 the eggs and young larv^ae of Icerya is contradicted. 



The writer has shown that the young larv^ae of Icerya are quickly 

 killed by spraj'ing the under surfaces of the leaves of the plant host with 

 soap-suds. 



1247 -Prevention of the Hessian Fly {Cecidomyia destructor — Mayetiola 

 destructor) in Kansas by Choice of the Season for Wheat Sowing. — See 



No. 11/9 of this Bulletin. 



(i) See also B. October 1916, No. 1140. (Ed.). 



(2) See also B. May 191 3, N" 621. [Ed.]. 



