ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 67 



Perhaps the most remarkable feature of the intricate organs described 

 is the elaborate development of friable seta? producing quantities of 

 dust. Fritz Miiller described such hairs in the wing-folds of Hesperid^ 

 and called them " chain-bristles," since they took the form of long hairs 

 constricted at regular intervals, and liable to break at each constriction. 

 The yellow " fluff " on the hind-wing of the male moth Erebus macrojys 

 consists mainly of " chain-bristles " of an exceedingly beautiful form. 



Life-history of Aleochara bilineata.* — J. T. Wadsworth describes 

 the life-history of Aleochara bilineata G-yll., a Staphylinid parasite of 

 Gliortophila brassicse, the common cabbage-root fly. The ova of A. 

 bilineata are deposited in the soil, probably near the roots of cabbages, 

 etc., which are attacked by C. brassicse. The larvae emerge in about ten 

 days, and are typical, free-living, campodeiform, Staphylinid larvai. 

 They enter the puparia of the cabbage-fly, feed on the pupse, and at the 

 first ecdysis emerge as cruciform larvne. They thus undergo a simple 

 form of hypermetamorphosis as a result of their parasitic mode of life. 

 Three ecdyses occur during larval life. It was previously believed that 

 the ova or larvae of the beetle entered the fly-larvae, but this has been 

 shown to be erroneous. After the first ecdysis the larvae feed rapidly ; 

 pupation takes place within the puparium of the host, and the adult 

 beetle gnaws a hole in it and emerges. Detailed descriptions of the ova, 

 larva, pupa and imago are given. Two generations of the Staphylinid 

 are produced in the district investigated (Manchester), and it is suggested 

 that in warmer areas three or more may be produced in a year. Adults 

 uf the first generation are produced in May or June, having entered the 

 puparium of their host as larvaj the previous autumn. Adults of the 

 second generation emerge in August and September, having completed 

 their development in six or seven weeks. The rate of development of 

 winter larvte may be greatly hastened by placing them in warm sur- 

 roundings. The percentage of puparia of the cabbage-fly found to be 

 infested with A. bilineata ranged from 10 to 26 p.c, according to the 

 season. The investigator estimates that about 20 p.c. of the larva3 and 

 pupae of (\ brassicse are destroyed by coleopterous and hymenopterous 

 parasites in the district where he obtained his material, and he suggests 

 that in view of the destructiveness of the fly the utilization of its 

 natural enemies is worthy of consideration. 



S. Arachnida. 



Variability in Size of Amblyomma.t — L. E. Robinson discusses 

 the variability in the size of the male of a South African tick, Amblyomma 

 hehraeum. In one set of eighty the length of the scutum ranged from 

 5 • 7-4 • 2 mm. ; the breadth from 4 • 9-3 • 5 mm. ; while the mean breadth 

 to length ratio was 0*85 approximately. In another set of sixty, the 

 length of the scutum ranged between 5 • 4 and 3 • 5 ; the maximum and 



* Journ. Econ. Biol., x, (1915) pp. 1-26 (2 pis. and 1 f g.). 

 t Parasitology, viii. (1915) pp. 11-16 (3 figs.). 



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