2il 



Imms (A.D.). Observations on the Insect Parasites of some Coccidae. 



—Quart. Jl. Micros. Sci., London, Ixi, no. 3, March. 1916, 

 pp. 217-274, 2 plates. 



Lepidosaphes ulmi, L. (mussel scale) is the commonest of the injurious 

 €occiDAE of Great Britain, attacking cultivated fruits and nursery 

 stock, especially apple. Observations made in Cheshire during 1913-15 

 showed that egg-laying begins about 17th August and continues into 

 September. A single brood occurs each year. The winter is passed 

 in the egg-stage beneath the old scale of the female and larvae emerge 

 about 21st May of the following year. The Chalcid, Aphelinus 

 mytUaspidis, Le Baron, is the most important parasite of L. ulmi in 

 England. It appears to be generally distributed throughout the 

 country. The parasite is double-brooded, only about 1 per cent, of 

 the adults being males. The adults have very weak powers of flight, 

 and consequently the migration is limited. In the first generation, 

 adults appear in the greatest numbers from the third week in June to 

 the middle of July. The female pierces the scale, and usually deposits 

 one egg on the surface of the host. The larval stage, during which 

 time A. mytilaspidis is ectoparasitic, varies from 23 days to more than 

 a month. The pupal stage is passed in the same position, the adults 

 emerging between the middle of August and the first week in September. 

 The adults of the second generation live for a period not exceeding 

 five days ; they are parthenogenetic, eggs being deposited on the 

 surface of sexually mature hosts. The resulting larvae have the same 

 habits as those of the previous generation, and become mature towards 

 the end of October or beginning of November. Hibernation takes 

 place beneath the scale of the host and adults emerge in the following 

 year. The results of parasitism by the first generation are complete, 

 the host invariably dying from the attack ; the efEects of the second 

 generation are partial, since parasitised hosts are usually able to deposit 

 a few eggs. The scales are parasitised to an extent of 7 per cent., and 

 the efficiency of the parasite is therefore much below that of a suitable 

 insecticide, by reason of (1) its limited powers of migration; (2) its 

 relatively low fecundity ; (3) its susceptibility to climatic changes ; 

 (4) the incomplete results of parasitism by the second generation. 



Britton (W. E.) & Davis (J. W.). Gipsy Moth Suppression Work in 

 1915. — Rept. Connecticut Agric. Expt. Sta. 1915, New Haven, 1916, 

 pp. 99-111, 1 fig., 4 plates. [Received 25th April 1916.] 



During 1915 the control work against the gipsy moth {Lymaniria 

 dispar) consisted of inspection, collection of egg-clusters and pupae, 

 banding with tanglefoot, and spraying. As the result of winter 

 inspection, ten towns were found to be infested. Summer work closed 

 on 24th July, except in the north-eastern corner of the state, where it 

 was continued until after 1st August. A special grant was made 

 during the year to enable control measures to be more effectively 

 carried out, and a new bill was introduced, making provision for towns 

 to carry on measures under the direction of the State Entomologist, 

 both against the gipsy moth and the brown-tail moth {Euprociis 

 chrysorrhoea). 



