559 



can liai'dly be considered as possessing anv great possibilities as a 

 means of artificial control of white-grubs, its action in producing death 

 being slow ; whether it ever produces mortahty of grubs on a large 

 scale in the open in Porto Rico during periods of heavy rainfall, as it 

 is said to do in some parts of the United States, is a question that 

 requires further investigation. L. vandinei has been previously 

 recorded under the name Lachnosierna grandis [see this Review. .Ser. A, 

 iv, p. 3G5]. 



Lachnosierna (PhijUopJiaga) porloricensis (common white grub), 

 being formerly considered as a variety of L. vandinei, has also been 

 previously recorded as L. grandis [he. cit.]. It has a life-history very 

 similar to that of L. vandinei, the feeding habits and food-plants being 

 almost identical. The latter include banana, coconut, breadfruit, 

 Banibusa v^ulgaris (bamboo), Theohroma cacao (cacao), and Mangifera. 

 indica (mango). Grasses other than sugar-cane are not as a rule 

 attacked and the cane appears only to be damaged when more 

 palatable foliage is not available. The beetle's life above ground is 

 believed to occupy between two and three months under normal 

 conditions, the egg-laying period covering about one month. The 

 insect parasites of this species are identical with those of P. vandinei, 

 the Tachinid, Crgjjfomeigenia aurifacies, Walt., being the most useful 

 enemy of the adults, and the wdreworm, Pgrophoriis hiininosus. 111., the 

 most efficient in destroying the larvae. These two ])arasites have 

 doubtless prevented the white- grub injury on the north and east 

 coasts of the Island from becoming anything like as serious as it has 

 been in some districts where these checks do not occur. The Tachinid, 

 Evirixoicles jonesi, Walt., and the Scoliid, Elis xanthonotus, may 

 prove to be j)arasitic on this species of Lachnosterna. About 8% of 

 the number of L. portoricensis reared in confinement were attacked 

 by the green muscardine fungus, but there is no indication that many 

 deaths result from this disease under normal outdoor conditions. 



Other species of Lachnosterna that are minor pests of sugar-cane, 

 and of which the life-histories and habits greatly resemble the more 

 important species dealt with, are given in tables and described in 

 detail, including L. gnanicana, formerly recorded under the name 

 L. media \loc. ciY.], which prefers dry, upland soil and has not yet 

 appeared in the cane-fields to any extent. The favourite food-plants 

 of this species are Psidium guayava (guava), Cordia cijlindrosteichys 

 (black sage), Lantana camara, and tamarind. L. citri, formerly recorded 

 asX. media, [he. cit.], feeds abundantly upon grape-fruit, orange, guava, 

 and many host-plants common to other species, and the larvae 

 frequently cause considerable injury to young citrus trees. Phytalus 

 ins^daris, formerly recorded as L. pequena [he. cit], has been found 

 feeding upon Aniaranthus sp. (pig-weed), and various grasses. In 

 experimental cages the adults fed upon maize foliage ; no examples 

 Avere observed feeding upon cane, though they occur j)lentifully in the 

 cane-fields and doubtless the grubs attack the cane roots. 



Cotton (R. T.). The Egg-plant Lace-bug in Porto Rico : Cqrythaica 

 monacha, Stal. — JL Dept. Agric., Porto Rieo^T, no. 3, Julv 1917, 

 pp. 170-173. [Received 18th October 1917.] 



The Tingitid, Corythaica motmcJia,, Stal, is the most serious of the 

 many pests of the egg-plant, Sohnum tnehngemi. It is found 



