137 



Maskew (F.). Quarantine Division. Report for the Month of May 



1917.— Mthhj. Bull. Cal. State Commiss. Hortic, Sacramento, vi, 

 no. 8, August 1917, pp. 347-348. [Received 24th January 1918.} 



The follo^ng pests were intercepted : — From Australia : Venturm 

 pyrina on pwFrs ; Rhizoctonia and Phthomnaea oj)erculdla on potatoes. 

 From China : Calandra oryzae in rice ; Lepidopterous larvae in dry- 

 herbs ; Coccids on plants ; Hemichionaspis sp. on lichi trees. From 

 Hawaii : Diaspis hromeliae and Psendococcus bronieliae on pineapples ; 

 Chnjsomphalus sp., Parhtoria sp., Pseudococcus sp. and cicada eggs on 

 palm ; larvae of Dacus cucnrbifae in cucumbers. From Japan : Mites 

 in bulbs, weevil larvae in chestnuts and sweet potatoes ; Pulvinana sp., 

 Hemichionaspis aspidistrae and Lepidosaphes sp. on citrus cuttings ; 

 Poliaspis pini on a pine tree. From Mexico : Calandra sp. in seeds ; 

 Lepidopterous larvae in seeds ; Lepidosaphes beckii on limes ; 

 Heliothis {Chloridea) obsolefa in tomatoes ; weevils in tamarinds. 

 From New Jersey : Diaspis boisduvali and Isoso)na catthyae on orchids. 

 From Panama : Lepidopterous pupae on orchids. From Papeete : 

 Morganelki mashelli and Lepidosaphes beckii on oranges. From 

 Pennsylvania : Dialeurodes citri and Coccus hesperidum on citrus trees ; 

 Saissetia hemisphaerica on gardenias. From Illinois : Aspidiotus 

 lataniae and Saissetia oleae on ornamental plants. From New York : 

 A borer (? Lixus concavus) in rhubarb roots. From Ohio : Pseudococcus 

 sp. and Orthezia sp. on ornamental plants. 



CoLLixs (G. N.). Breeding Sweet Corn Resistant to the Corn Earworm, 

 — Jl. Agric. Research, Washington, D.C., xi, no. 11, 10th December 

 1917, pp. 549-572. 



Sweet maize is grown very little in the southern L^nited States or iu 

 the tropics generally, the chief reason probably being the ravages of 

 the corn earworm, Heliothis {Chloridea) obsoleta, F., which generally 

 destroys almost the entire crop, whilst the native field varieties suffer 

 but little injury and are consequently largely used as a substitute. 

 The most obvious difference between the sweet and field varieties that 

 might be expected to afiect the activities of this caterpillar is the 

 extent to which the ears are protected by husks. The husks in sweet 

 varieties are generally poorly developed, perhaps because in the maize- 

 growing belt one of the most desired characteristics is an early season, 

 and early varieties generally produce few leaves and few husks. 

 Crosses were therefore made between commercial varieties of sweet 

 maize and southern field varieties in order to combine the well- 

 protected ears of southern varieties with the eating qualities of 

 sweet varieties, hoping to raise a strain of sweet maize with some 

 degree of immunity. These hybrids were found to possess distinctly 

 greater immunity than the commercial sweet varieties, while the 

 constitution of the plant was also found to be an important 

 factor in immunity. A small percentage of damage was found 

 to be correlated with a number of morphological characters, of 

 which prolongation, or the extent to which the husks exceed the ear, 

 was apparently the most important. The thickness of the covering 

 provided to the ear by the husks was also found to be associated with 

 low damage, but since only 5 per cent, of the larvae that reach the ear 

 (C458) Wt.P2/137. 1,500. 4.18. B.&F.Ltd. Gp.11/3, A 



