304 



The concluding section of this paper deals with the symbiosis of 

 inicro-organisms mth insects. Li 1858 Huxley described a curious 

 organ in Aphids which Karel Sulc in 1910 showed to consist of two 

 parts, containing fungi of two different orders. Forbes described 

 symbiotic organisms in Blissus leucopterus, in Lygaeids and Coccids, 

 and they have also been described in Hemiptera, Hymenoptera and 

 Lepidoptera, notably in Pieris brassicae. It has been observed that 

 in certain instances Isaria fungi are symbiotic, while in others they are 

 pathogenic to insects ; according to Portier, the juices of the insect 

 •contain a substance which inhibits the development of the mycehum 

 "of the fungus while permitting the conidia to develop. 



The valuable bibliography appended to this paper, gives a list of 

 157 works : 67 on entomophytic fungi, 26 on sporozoites, 16 on 

 bacteria, 30 on diseases of unknown origin, and 18 on the symbiosis of 

 inicro-organisms with insects. 



Lesne (P.). Observations sur la mouche de I'asperge; essais de 

 pi6geage. [Notes on the asparagus fly ; Trapping experiments.] — ■ 

 Ann. Service des Epiphyties, Paris, ii (1913), 1915, pp. 266-272, 

 4 figs. [Received 11th May 1916.] 



In 1913 Platyparea poeciloptera, Schrank (asparagus fly) in the 

 Argenteuil district began hatching from asparagus stems on 25th 

 March, 18 days earUer than the date observed in 1904 [see this Review, 

 Ser. A, ii, p. 403]. This circumstance shows the advisabihty of burning 

 dead stalks before the end of March. A case was noticed where stalks 

 which had not been earthed up, were attacked and rapidly killed 

 although they were of vigorous growth, thus demonstrating the 

 importance of this operation. Trapping experiments were begun on 

 7th June with saucers filled, either ^vith fermented cider and molasses, 

 or with a mixture of wine and honey in equal parts. Many other 

 insects were captured, but only one example of P. poeciloptera over a 

 period of 10 days. These sugared bait-traps were therefore useless 

 at this somewhat late date. Adhesives also proved ineffective. The 

 best control would seem to be a search for its natural enemies in the 

 normal habitat of this pest and their introduction into the districts 

 where asparagus is grown. 



VuiLLET (A.). Action des fumigations d'acide cyanliydrique sur le 



Diaspis pentagona, Targ. [The action of hydrocyanic acid gas 

 fumigations on Aulacaspis pentagona.] — An7i. Service des Epiphy- 

 ties, Paris, ii (1913), 1915, pp. 285-287. [Received 11th May 

 1916.] 



In experiments with hydrocyanic acid gas against Aulacaspis 

 pentagona, ten tests were made ^yith doses of potassium cyanide 

 varying from about 2 to 4 grains per cubic foot, the mortality varying 

 from 98 to 100 per cent. While absolute disinfection is not possible, 

 this insecticide may be used to advantage in the case of imported 

 plants. In no case should inspection on arrival be neglected and very 

 heavily infested shipments should be destroyed. 



