Vol. XVIII. No. 453. 



THE AGEICULTURAL NEWS. 



283 



occurring in Cuba, Porto Rico, and Guadeloupe. It was known 

 to science as long ago as 1787, but it appears that nothing 

 was known previously with legard to its various stages, 

 seasonal history, habits, etc. It has been known in Florida 

 since 1866, but it is only within the past three or four 

 years that it has been recognized as a pest of casuarina. 



The adult beetle is a small insect of a metallic greenish- 

 bronze, colour. The female measures from 13-5 to i / mm., 

 and the male 12-5 to 1-4 mm. in length. Both sexes are 

 fond of bright sunlight and are commonly found flying from 

 10 a.m. to 3 p m. They feed on the tender, succulent bark 

 of trees they infest. 



The eggs are inserted under the thin outer layer of dry 

 bark of the mangrove. When the eggs hatch the larvae bore 

 into the soft bark to tlie wood where they remain feeding on 

 the cambium until nearly full grown ; at this stage the 

 larva bores into the wood and excavates the pupal cell and 

 provides a tunnel by means of which the insect will make its 

 way to the outer world as a beetle. 



One year is required for the development of the man- 

 grove borer from egg to adult. Su far as is known, this 

 insect attacks only living red mangrove and the casuarinas. 

 It is not a 1 orer in dead wood. 



In Florida both these trees have been killed by this 

 borer, and the killing out of the tops or the main stem 

 and forcing growth into the branches producing a stag-head 

 effect appears to be a characteristic form of injury. 



The pfst may he controlled in casuarina by scraping the 

 bark and digging out the grubs, and by spraying the stems 

 with a poisoned oil emulsion, made according to the 

 following formula : — 



Standard miscible oil 1 pint 



Water 5 gallons 



Sodiam arsenate J-B). 



Dissolve the arsenate in water, stir, then add 1 pint 

 of miscible oil. Casuarina trees in infested localities should 

 not be pruned from April to August, as the flow of sap 

 will attract the flying beetles to the trees. 



NEW PLANTS AT THE DOMINICA 

 GARDENS. 



The following notes appear in Mr. Joseph Jones'.s Annual 

 Report on the Dominica Agricultural Department for 1918-19, 

 which is just being issued. 



The Mexican apple {Casimiroa ediiUs), introduced seven 

 years ago, fruited early in 1919. This species doe.s not do 

 well in the Gardens, but it grows with considerable vigour 

 in the stiff soil at Morne Bruce. The two specimens were 

 blown over in 1916, though not uprooted. Vigorous sucker 

 growth followed, and fruit wa.s produced as stated. Owing 

 to the exceptional drought experienced at this time, only a 

 few fruits matured. These were found lo possess an agree 

 able taste. The seeds are said to be poisonous. 



A couple f'f plants of the Rambutam (Nepke/iiim lap- 

 pactum) were raised from seed received from the Botanic 

 Gardens, Buitenzorg, Java, one of which is growing vigor- 

 ously. Seeds of Nepheliiim mutahih-, received from the 

 same place, failed to germinate. 



The Gardens now possess four healthy young trees of 

 Toutaria suavis native to Uruguay, which is said to yield 

 an agreeable fruit. Several plants have been distributed lo 

 planters for trial. 



The two specimens of the .laboticiba (Myrciana 

 (auliflord), a fruit tree of Brazil, are not so promising as 



when in their early stages. It would appear that the climate 

 of this island is not altogether suitable for them. 



All attempts to establish the Brazil nut {Bertholetia 

 exci'/sa), which have extended over a number of years and 

 under varying conditions, have resulted in failure. A few 

 plants of Lecythis Za/'i/ui/n, the Sapitcaia nut, grown by the 

 Department, make poor growth and are apparently not well 

 suited to our climatic conditions. On the other hand, the 

 Suvvarri nut {Caryocar iiiiriferum) grows extremely well, 

 and fruits at an early age. This fine tree should be largely 

 grown in Dominica, both on account of its appearance and for 

 the well flavoured nut which it bears. 



In the progress report for 191516, mention is made of 

 the receipt from British Honduras, of seeds of a species of 

 Achras, said to yield the Chicle gum of commerce. A few 

 plants placed out in the Gardens have made fair progress, 

 but some years may elapse before they reach an age to be 

 tapped. Now that communications with the various 

 Colonies are becoming normal again, it is hoped to obtain 

 from British Honduras further supplies of seeds from trees 

 which are known to yield the best quality gum. 



SHE.V BUTTER TREE. 



Mention is made in the Annual Report for 1913-14 of 

 the fruiting of the Shea Butter tree which had been received 

 from Kew fourteen years previously. The low rate of germi- 

 nation of these seeds, and the very slow growth of the seed- 

 lings were commented upon. 



In the report for 1916-17, reference was made to the 

 receipt of twenty-five seeds of this tree from the Agricultural 

 Department, Northern Nigeria, the native country of this 

 spectes. The seeds proved to be considerably larger than 

 those borne by the solitary specimen in the Botanic Gardens, 

 and it was thought desirable to forward a sample of the 

 seeds grown in Dominica to the Imperial Institute for com- 

 pari.=on with the African product, and for examination 

 and report. The information requested was kindly furnished 

 by the Director, and is reproduced in the report. 



It is necessary to point out that the Shea Butter tree in 

 Dominica is growing under very different conditions from 

 those of its habitat, which has a very dry climate The 

 rainfall of the Botanic Gardens, Dominica, is twice as heavy 

 as those parts of Noilhern Nigeria in which the Shea Butter 

 tree thrives. 



The seven seedlings which are growing in the Experi- 

 ment Station are healthy and promising, but in size they 

 are very small for their age. 



Considerations of the causes and conditions of heat 

 production in plants are referred to in Physiological Abstracts 

 for July 1919. The conclusion is arrived at that heat pro- 

 duction is not dependent on any regulatory power of the 

 plant, nor is it dependent oo external conditions, but on an 

 interplay between external conditions and specific protoplas- 

 mic properties. 



From reports in the Louisiana Planter it appears 

 that the work of the central factories in Cubi thi.s year has 

 been interfered with by the weather. Nor is the weather 

 satisfactory from the sCindpoint of the cane grower, for m 

 many parts of the island the heavy rains, while they have 

 helped part of the present crop, have been too much for the 

 younger cine- The unusual amount of rain received m 

 July prevented to a great extent the cleaning of the fields 

 necessary for the best growth of cane. 



