455 



autumn probably hatch in May or early June and reach the adult stage 

 in July. The nymphs live beneath the surface litter or in crevices 

 round the base of the host plant. The control of this species is best 

 effected by crop rotation and by ploughing in late autumn and early 

 spring. Spiders are predaceous on the underground stages. A.striatus, L., 

 occurs on grass land in which there is an abundance of timothy grass 

 which is probably the favourite host plant. The winter is almost 

 certainly passed in the egg stage. Hatching takes place during June, 

 and the nymphs are usually found either on the ground or on the host 

 plant near its base. Young nymphs probably attack the base of the 

 stems or the crowns, while in later stages they injure the stem and 

 leaves. Adults are more active than the nymphs and can be taken 

 readily by sweeping. The first adults were obtained at Orono on 1st 

 July ; both sexes were abundant by the end of the month. Crop 

 rotation and the burning over of infested land in autumn are recom- 

 mended. Chlorotettix unicolor is found on rank grasses in the 

 southern parts of the State. Nymphs are abundant in July and adults 

 during July and August. There is probably one generation annually. 

 Idiocerus provancheri occurs in bogs, and nymphs and adults have 

 been collected in July. Dmecvlacephala angnlifera, Walk., has 

 been found in the nymphal stage during the summer ; there is probably 

 one generation each year. Two specimens, doubtfully referred to 

 Phlepsius apertus, van D., were taken on timothy grass. BalclutJia 

 punctata, Thunb., is widely distributed, occurring especially on Canadian 

 blue grass, upon which all stages have been found during August. 



EwiNG (H. E.). Eighty-seven Generations in a Parthenogenetic Pure 

 Line of Aphis avenae, Fab. — Biol. Bull., Marine Biol. Laboratory, 

 Woods Hole, Mass., xxxi, no. 2, August 1916, pp. 53-112, 

 19 figs., 12 tables. 



In these experiments, the effect of continued parthenogenetic 

 reproduction on virility and metabolism and that of temperature on 

 growth, size, reproduction and dimorphism was studied. In addition 

 to results bearing especially on these points, other general conclusions 

 were reached. The optimum temperature for the production of 

 wingless agamic forms is about 65° F. ; the percentage of winged 

 forms increases above and below this temperature. A constant 

 temperature of 90° F. completely prevents development. Continued 

 parthenogenetic reproduction shortened the growth period, but did 

 not affect the size or fecundity of the strain used. Paedogenesis 

 occasionally occurs among winged and wingless nymphs. 



South (F. W.). Summary of the Locust Work for the 1st Quarter 



1916. — Agric. Bull. Fed. Malai/ States, Singap&re, iv, no. 9, June 

 1916, pp. 291-297, 1 table. [Received 7th September 1916.] 

 Three locust swarms were observed at the beginning of the year in 

 Selangor, but the breeding of these was either delayed or failed com- 

 pletely, since no young forms were found as late as the end of April. 

 In the Tampin District of Negri Sembilan young hoppers appeared in 

 large numbers at the end of March. This state of affairs is attributed 

 to defective scouting work in February and the beginning of March 

 and to the entrance of flying swarms from Johore and Malacca. 



