ECONOMIC ZOOLOGY ENTOMOLOGY. 747 



the Importance of immediately sacking up tlie seed, preferably in sacks of 

 lieavy ,cloth such as canvas, free from holes, so that moths can not get to the 

 seed to start another infestation. 



The insects mentioned as belonging to the second class include tli£ conchuela 

 {Pentatoma ligata) and grasshoppers. The conchuela, an account of which by 

 Morrill has been previously noted (E. S. R., 23, p. 461), has become a pest in 

 the area in which the sorghum midge is scarce or absent on account of insufli- 

 cient moisture. Its sucking of the sap from either the stem or seed head results 

 in a rapid wilting or burning of the infested plants and their heads. As yet 

 large areas of Sudan grass have not been grown in the localities where the 

 conchuela is at present abundant. Where grasshoppers appear in sufficient 

 numbers to cause injury, the weed patches should be sprayed with a sweetened 

 arsenical, care being taken to keep all stock from grazing on these patches until 

 after several hard rains. 



The insect enemies of the fig, F. Picard {Prog. Agr. et Vit. {Ed. I'Est- 

 Centre), 35 {1914), KTo. S6, pp. 279-286, pi. 1; abs. in Rev. Appl. Ent., 3 {1915), 

 Ser. A, No. 1, pp. 10, 11). — A general account of eight of the more important 

 enemies of the fig illustrated by a colored plate. 



Notes on the development of Bacillus pestis in bugs (Cimex lectularius) 

 and their power to convey infection, A. W. Bacot {Jour. Hyg. [Camhridge'i 

 Plague Sup. 4 {1915), pp. 1177-792, pis. 2, fig. 1). — ^The author's conclusions are 

 "that for a percentage of bugs {C. lectularius) and probably all newly hatched 

 ones a meal of septicemic blood from a mouse dying of plague is fatal. Bugs 

 which are not killed by the infecting meal are capable of carrying B. pestis 

 and reinfecting mice after a period of 48 days' starvation. The development of 

 B. pestis within the crop of bugs differs generally from that which takes place 

 in the stomach of the flea in respect of its slower and looser growth, this limi- 

 tation of activity being accompanied by and possibly due to the preservation 

 of the structural character of the blood for many days after its ingestion into 

 the crop. 



" The absence of any definite valve between the pump and the crop, together 

 with the looser nature of the growth within the bug, preclude the idea of such 

 mechanical blockage as causes regurgitation and mouth infection by fleas. It 

 may be surmised, however, that mouth infection, when not caused by accidental 

 or other injury to the bug while feeding, may be due to interruption followed 

 by a second attempt." 



Natural enemies of the sugar beet leafhoppers in California, W. J. Hartung 

 and H. H. P. Severin {Mo. Bui. Com. Hort. Cal., 4 {1915), No. 5-6, pp. 277^ 

 279). — In order to determine the percentage of parasitized leafhoppers {Eutettix 

 tenella) 500 specimens, collected at King City on September 2, 1913, by sweep- 

 ing with an insect net beet leaves showing a severe condition of " curly top," 

 were placed in breeding jars and vials containing beet leaves and stems which 

 served as food material. During the following three weeks twelve puparia of 

 dipterous parasites which represent two new species described by F. Knab as 

 Pipunculus industrius and P. vagabundus were found at the bottom of the 

 breeding jars and vials, together with twelve dead leafhoppers; four jassids 

 were parasitized by a dryinid. 



At least 3.2 per cent of the leafhoppers were parasitized during the season 

 of 1913 by dryinids, which have been determined by Rohrer as Gonatopus con- 

 tortulus and Labeo n. sp. Data relating to the parasitism of leafhoppers during 

 1914 are presented in tabular form. It appears that 33.6 per cent of leafhoppers 

 were parasitized and in addition a fungus disease was observed. 



A bibliography of seven titles relating to the subject is included. 



