171 



for by the fact that some varieties of this fruit are much more sus- 

 ceptible to fruit-fly attack than others. While the infestation of host- 

 fruits in general was as great as in 1917, the parasitism of the larvae 

 developing in the majority of the abundant fruits infested, such as 

 Indian almond {Terminalia catajrpa), coffee {Cqffea arabica), strawberry 

 guava {Psidium cnftleyawum), and French cherry {Eugenia unijlora), 

 was higher than in previous years. The most important of the abundant 

 fruits producing a low percentage of parasitism are the mango, kamani 

 {Calophyllum inophyllum), Chinese orange {Citrus sp.) and guava 

 ■{Psidium guayava). The low parasitism of the larvae developing in 

 these, especially in guava, wliich is cultivated in large areas in all 

 parts of the Islands, indicates that these fruits are the source of supply 

 of the large number of fruit-fhes that cause the continual high infestation 

 of favoured food-plants. 



_Previous records [R.A.E., A, iii, 412 ; iv, 289 ; vi, 167 & 185 ; 

 vii, 43] show the consistent ascendancy of the parasite Diachasma 

 iryoni over Opius humilis during the warmer months of the year and 

 the predominance of 0. hmnilis in the cooler months. This is due to 

 the ability of D. tryoni to destroy 0. humilis when both occur in the 

 same host-larva, and the increased activity of the former durino- the 

 cooler months. While in 1916 and 1917 0. humilis gained^ this 

 predominance for 5 and 3 months respectively, during 1918 the period 

 was two months only. This yearly decrease in the effectiveness of 

 O, humilis is due to the increasing abundance of D. tryoni. The average 

 parasitism by the latter has increased from 13-3 larvae to each frmt 

 m 1916 to 20-3 m 1917 and to 34-6 m 1918. Although the parasitism 

 by both D.fuUawayi and T. giffardianus was less in 1918 than in 1917, 

 the total percentage of parasjtism for the last year, on account of the 

 increased effectiveness of D. tryoni, had increased by 8*3, making the 

 total parasitism for 1918, 55-8 per cent, of all the fnut-fly larvae under 

 observation. Thus the value of the parasites of C". capitata has 

 consistently increased each year since their introduction, conferring 

 benefit upon the people of Hawaii by greatly decreasing the infestation 

 of those fruits wliich are less susceptible to frmt-fly attack and which 

 include the majority of fruits of commercial value, and upon the fruit- 

 growers of the United States by greatly decreasing the danger of 

 introducing fruit-flies into that country. 



Beeson (C. F. C). Insects attacking YemanL— Indian Forester, 

 Allahabad, xlvi, no. 2, February 1920, pp. 85-86. 



As it has been recorded that plantations of yemane {Gmelina arborea) 

 are not materially damaged by insects, the author points out that the 

 tree is by no means immune from insect attack. The Cassidid, 

 Calopepla /-m?/ana,Latr., regularly defoliates the trees durmg the rains; 

 a weevil which may be Alcides ludificator, Fst. (known as the pith borer 

 of teak in Burma) bores the shoots ; the Longi corns, Haplohammus 

 cervinus, Hope (teak canker grub) and Glenea galathea, Thorns, (also 

 a breeder in teak), bore the stem near the ground-level ; and the 

 Hepiahd, Phnssus sigmfer, Wlk. (ghost moth), an important borer 

 of sapling teak, makes beeholes when in the larval stage. 



In view of the proposal to estabhsh pure blocks of^emane in con- 

 junction with pure blocks of teak, it is thought probable that the 



(673) ^2 



