96 



No new light has been thrown on the question of aestivation. The 

 arguments in favour of the theory of local hibernation are as follows : — 

 (1) The fact that the same area is attacked year after year probably 

 indicates that the pest is of local origin and not a migrant. (2) The 

 fact that in a fresh area the attack gradually increases in extent and 

 intensity year by year seems to support the view that the insect is 

 local. Observations tend to show that the insect may at first migrate 

 to a suitable locality, which then becomes the permanent breeding 

 ground, the progeny of the first-comers gradually extending to a wider 

 tract of land. (3) The first catches of the season do not have the 

 appearance of having travelled a long distance. (4) A distinct interv^al 

 occurs between broods in two contiguous tals [see this Review, Ser. A, 

 iii, p. 320]. 



During the last four campaigns a gradual increase in the propor- 

 tion of males to females has been noted. Examination of moths 

 for egg-contents showed that the percentage of gravid females 

 full of eggs was higher in the first few months than in December or 

 November. It would appear that in Agrotis the attraction for Andres 

 Maire traps is stronger than the egg-laying instinct. This fact has an 

 important bearing on the successful issue of the campaign. 



DuTT (H. L.). The Soy Bean Stem-Borer. — Agric. JL, Dept. Agric, 

 Bihar and Orissa, Patna, iii, no. 1, April 1915, pp. 52-56, 3 figs. 

 [Received 7th January 1916.] 



A Cerambycid beetle, Nupserha sp., has caused considerable damage 

 during the past three years to an experimental plot of soy beans at 

 Sabour. The adult insect is nocturnal in habit. When ovipositing, 

 the female selects a young green shoot which it girdles at two points 

 about half an inch apart and from 2 to 2^ inches from the apex. The 

 eggs are laid singly in the pith 2 or 3 mm. above the lower girdle. The 

 buds and leaves above the girdles begin to droop in four or five days 

 and finally die. The incubation period is nine or ten days. The larva 

 on hatching tunnels along the pith, generally towards the main stem. 

 The larval stage lasts more than six weeks, pupation taking place in a 

 cell in the tunnel. The adult emerges in about eight days through a 

 hole made ih the stem. The larva hibernates inside the stem of the 

 host plant, emergence from hibernation probably taking place after 

 April. Attack is first noticed in the field in May or June on self- 

 sown soy bean plants. On the regular crops, injury appears in July, 

 when the plants are from 9 to 12 inches high. The insect is active 

 throughout the rains until harvest, there being probably three broods 

 annually. In controlling the insects, affected twigs should be picked 

 off and destroyed within two or three days of egg-laying. After the 

 harvest, the land should be ploughed and the dry stubble burnt to 

 kill hibernating larvae. Broken branches should be collected from 

 the threshing floor and burned. 



Bkittain (W. H.). The Green Apple Bug on Apples and Pears. — 



Canadian Horticulturist, Peterboro, Ont., xxiii, no. 12, December 

 1915, pp. 269-270, 4 figs. 



Lygus invitus (false tarnished plant bug) is distributed throughout 

 the fruit-producing centres of the Annapolis Valley of Nova Scotia. 



