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the steppes into cultivated land, on which locusts do not breed. 

 Owing to the beginning of field cultivation in the Persian Moghan 

 steppes in 1912, the migration of the insects in 1913 into Kussian 

 territory was much smaller and occurred considerably later. It is 

 thought that the reduction of the steppe areas and the increase in the 

 area of cultivated land make it ui\neccssary for the pests to undertake 

 large migrations, as they find sufficient food on the spot. 



The author describes his observations in the governments of Baku 

 and Elisavetpol, where he was sent in 1913 by the Department of 

 A-griculture in order to demonstrate the chemical method and to 

 investigate and report on the necessary organisation of the campaign 

 in future. The usual method of control consisted in driving the locusts. 

 into trenches, etc., and their destruction by various mechanical means. 

 Experiments and demonstrations on the spot with spraying apparatus- 

 were most successful, the best insecticides being : — (1) 5 lb. of sodium 

 arsenite in powder and 20 lb. of potato molasses dissolved in 135 

 gallons of water; and (2) 5 lb. of Paris green (mark 707), 8 lb. of sal- 

 ammoniac and 40 lb. of molasses in 135 gallons of water. The first of 

 these insecticides is somewhat cheaper, one charge costing 4s. 3d. as. 

 compared with 5s. 4d. in the second case. The day after the spraying, 

 90 per cent, of the hoppers were dead and in a few days there were no- 

 living ones left, even those arriving later being poisoned. Although 

 there are many places in Transcaucasia not covered with plants, the 

 author is of opinion that that fact cannot serve as a reason against 

 the chemical remedy ; the insects always oviposit on steppes, where 

 the upper layers of the soil is full of small roots of various plants and 

 grasses which, at the moment when the larvae hatch out in spring, 

 provide sufficient food for their development. The larvae of D. 

 maroccanus are largely polyphagous, feeding on all kinds of steppe 

 plants. Various soapy and other such insecticides, which have an 

 external effect on the larvae as contact poisons, are not recommended, 

 as they are expensive and uncertain in their effects, and the spraying 

 with them requires hand apparatus with high pressure and a strong 

 spray. The campaign against the larvae of D. maroccanus was conducted 

 in various parts of the country mostly by means of trenches (some of 

 them having wells in their bottoms and others being filled with water), 

 by iron shields, and by burning. G ood results were obtained by applying 

 the shields in combination with burning. The trenches filled with 

 w^ater proved less effective than ones in which the larvae were 

 automatically killed, those below being crushed by the weight of 

 those above, the trenches being covered with earth when quite full. 

 The hatching of the larvae from the eggs took place in the first half of 

 April, and continued for seven or eight days ; the development of 

 the first stage hoppers lasted about eight days, of the second, about 

 seven ; third and fourth about eight each ; the fifth about ten. 

 Winged forms appeared between the IGth and 26th May. Oviposition 

 was finished by the local individuals in the first half of June, while the 

 insects which arrived from Persia oviposited until 29th June. The 

 insects disappeared finally on 3rd July ; the whole cycle from egg to 

 imago thus lasting, in 1913, 41 days. The fourth and fifth larval 

 stages and the imago are the most injurious. Amongst the natural 

 enemies of D. maroccanus in Transcaucasia are rooks, crows, jackdaws, 

 starlings, a lizard {Ophisaurus sp.), Mylabris i-punctata, M. f oralis. 



