78 



THE AOKICULTUEAL NEWS. 



Maik H 1, 1913. 



FUNGUS NOTES. 



MISCELLANEOUS ENTOMOGENOUS 



FUNGI. 



In the Kev liullttiti. No. 8, 191'2, p. 3-58 appears an 

 account by Massee of a new species of Isaria, found by 

 Mr. W. H. Patterson, on the Gold Coast, as a parasite of the 

 green plant bug {Xe.ara vividula). This new species has been 

 named /. Pnttersonii. In the paragraph following the techni- 

 cal description, Massee writes as follows: 'As a rule the 

 insect is completely covered with a downy or minutely velvety 

 nap, from which spring numerous, more or less erect, 

 variously divided branches, bearing the very minute conidia 

 at their fiml)riate tips. The interior of the scale (i.e. of the 

 green plant bug) is completely filled with a white .stroma 

 formed of densely compacted hyphae. From analogy, this 

 fungus must be considered as the conidial condition of 

 a species of Cordyceps.' 



In October 1912, specimens of the same insect were 

 forwarded from Grenada by Mr. Auchinleck, Superin- 

 tendent of Agriculture, and these were i)arasitized by 

 a whitish fungus. Pure cultures of this organism were 

 obtained on nutrient agar plates, and on cylinders of steamed 

 sweet potato on which it grows with considerable vigour. 

 At the same time a culture in a tu'ie of nutrient agar was sent 

 to the Koyal Botanic Gardens, Kew, and there identified by 

 AVakefield as being the .same fungus as that found on the 

 Gold Coast, namely Isaria Pattenoiiii. Pure cultures on 

 steamed sweet potato cylinders have been sent to Grenada 

 for the purpose of conducting inoculation experiments, and 

 if these are successful, it is hoped that some use may be 

 made of it on a large scale in controlling the green plant 

 bug, as this was reported to be doing serious injury to 

 certain crops in the island during the e.xceptionally dry 

 season experienced last year. In this connexion it is interest- 

 ing to note that Mr. Sands, the Agricultural Superintendent, 

 St. Vincent, reports the existence of a parasitic fungus on 

 the green plant bug in the neighbourhood of the Experiment 

 Station in that island, but the identity of this organism is 

 not known, as no specimens have as yet been examined. 



Asrliers'iiiia turhhuita, to which reference was made in 

 the A'n-irultural Neirs:, Vol. XI, p. 270 is of fairly common 

 occurrence on the soft green scale insects, especially the 

 mango shield scale, and with it is sometimes found another 

 species A. cuUnsis. \et a third species, A. takitmnis has 

 been reported from certain localities in the West Indies, 

 among them from Jamaica. It is peculiar, however, that the 

 species parasitic on white Hy, two of which have I>een found 

 so useful in Florida, do not appear to occur naturally in the 

 West Indies, as none have jet been brought to the notice of 

 this Department. Afr/icrscn/a ai yrodis is reported to occur 

 on white fly in Cuba, but it was probably imported from 

 Florida, where it is one of the two common species. 



Some interesting work on the fungus parasites of insects 

 attacking the sugar-cane has recently been conducted by 

 A. T. Speare in Hawaii, and an account of it is published in 

 Bulletin No. 12 of the Pathological and Physiological Series 

 of the Hawaiian Sugar Planters' Association. Two new 

 species of fungi are described as parasites of the jtink mealy- 

 bug (Pscucloroccus calcf'lariae) found commonly in the West 

 Indies as well as in Hawaii on the nodes of sugar-cane when 

 these are protected by dd leaf sheaths. The first of these 

 fungi is Eiitoiii(,pliili(i)(i jis' mloi-occi, a species which, even 

 when fruiting, is only with great ditHculty distinguishable 

 from the waxy covering of the insects unle.'is the observer is 



acquainted with it This fungus changes the characteristic 

 pink colour of the healthy insects, to a chalky white appear- 

 ance when the host is in the last stages of the disease. The 

 body wall of the insect, usually quite flexible, is rendered so 

 brittle that when it is touched with a pair of forceps 

 a rupture occurs. Inoculation experiments showed clearly 

 that the fungus is a true parasite, as might be expected from 

 its systematic position. At times, this, with that about to be 

 described, acts as a most efficient control of the mealybugs. 

 Nothing is known of the existence of any fungus of this 

 genus on the pink mealy-bug in the West Indies, though it 

 is quite possible that it does occur, but has been overlooked, 

 since it was only accidentally observed in Hawaii owing 

 to its inconspicuous habit. 



The second parasite on this insect is a species of Asper- 

 gillus, thought by Speare to be .so far undescribed and named 

 by him A. jiaradticus. The spores of this fungus are bright 

 green in colour and impart a bright-green mealy appearance 

 to the bodies of the insects attacked. Inoculation experi- 

 ments showed that it was a true parasite independent in its 

 action of the Entomophthora, and that it was more virulent 

 on the young than on the older insects. It is of considerable 

 interest to note that an Aspergillus of much the same colour 

 and appearance, possibly even identical, is of very common 

 occurrence on the pink mealy-bug in the Lesser Antilles and 

 has also been found in Porto Itico. No experiments have 

 been conducted as yet to test the parasitism of the local 

 species, but the work done in Hawaii renders it at least 

 probable that the West Indian form is a parasite, in which 

 case it must be regarded as a control on the insects capable of 

 producing a fairly definite effect. 



A third entomogenous fungus recorded on sugar-cane 

 in.sects from Hawaii, is the green Muscardine {Mfarrhizium 

 aniso2)line) best known in the West Indies in connexion with 

 the frog-hopper in Trinidad It was found in Hawaii on the 

 weevil borer {RliaMocvemis [SphenophorusJ ohsmra,) and on 

 the '.Japanese beetle' a hard back (Adorelin umhrosus): 

 also more recently on a cane root-grub of the genus Anomala! 

 As has been pointed out elsewhere, this fungus is of very 

 wide geographical distribution, and occurs on a variety of 

 insects. It does not seem to have been recently imported into 

 Hawaii, but with the exception of Trinidad, has not been 

 recorded naturally from the West Indian islands. E.vperiments 

 have been planned to test its parasitism on two species of .May 

 bug, l.achnostiriiajiatruelis in St. Kitts, and Lacltnnstema sp. 

 in Antigua, found in the soil at the roots of canes and prob- 

 ably the cause of a certain amount of damage to this crop. 

 Experiments are also in progress in Porto itico in connexion 

 with another species of Lachnosterna known to be a pest of 

 the sugar-cane. 



Speare's paper concludes with a short note on a sterile 

 species of Cordyceps found on the cane leaf hopper {Perldn- 

 su'Ua sacc/i'iricida). This was at one time quite abundant in 

 wet regions in Hawaii, but now has become rare owing to the 

 comparative scarcity of the host insect 



In Colonial Heporls —A.nnua.\, No. 741, it is stated that 

 the export of oranges from the Pahamas during I it 11- 12 w.is 

 only l.'j.400 valued at £20 as against 42,l:iO valued at £(')S 

 in 1911. In 1907 the export was over a million and a half 

 fruit valued at £3,000. This enormous decrease is said to 

 be the result of the cessation of operations by the Canadian 

 Company. The cultivation of Sea Island cotton, in the 

 Bahamas, has, so far, not been satisfactory. Want of rain 

 or rain at the wrong time, destructive pests, and the want 

 of cheap ginning facilities have militated against success. 



