July 27, 1888.] 



SCIENTIFIC NEWS. 



83 



Natural ^mw£* 



THE STAURONOTUS MAROCCANUS; ITS 

 DEPREDATIONS IN ALGERIA. 

 M. Kunckel d'Herculais, the eminent French entomo- 

 logist, gives the following report of his observations in 

 the Algerian provinces attacked : — 



In the district of Tiaret the surface covered by the eggs 

 of these insects in 1886 was estimated at 8,400 hectares, 

 a hectare being approximately 2^ acres ; in the district of 

 Batna 130,000 hectares were infested; and in that of 

 Setif the surface filled with eggs was more than 20,000 

 hectares. But these figures are far below the reality, 



regularity which many generals might envy. They do 

 not march in column like the ants, or like our armies, 

 but they advance forming a front of a more or less con- 

 siderable extent. They do not appear to have any 

 leaders, but they are doubtless directed by senses whose 

 perfection we do not understand. Quitting the dry 

 mountains, they march straight forward, traversing each 

 day a regular stage. They travel from 9 a.m. to 3 or 4 

 p.m., and advance about no yards daily. They halt if 

 a cloud overshadows the sun, and the3' suspend their 

 march altogether if the temperature falls or if rain comes 

 on. They undergo five successive moultings, and become 

 more vigorous and agile. In two or three weeks they 

 are half-grown and measure then about | of an inch 



Locusts in Algeria Laying their Eggs. 



since in the mountains there are immense egg districts 

 which have escaped investigation. 



Suppose that we are in April, and the sun begins to 

 warm the soil. All at once, on the slope of the arid 

 mountain where a deposit of eggs had been formed the 

 year before, there issue from the earth thousands of 

 small, white, feeble beings of about a quarter of an inch 

 in length. On exposure to the light they soon take a 

 dark-brown colour, and the earth seems sprinkled over 

 with little black specks. Five men fell to work one day 

 to count them into a quarter-litre measure, which held 

 12,285 individuals. This gives 50,000 to the litre, or 

 5,000,000 to the hectolitre. Hence we may calculate 

 that each spot of 50 square metres may contain 

 25,000,000 of young locusts. 



Six days elapse, when the little tender, delicate beings 

 become strong in their limbs. Hunger makes itself felt, 

 and they set themselves in motion, with a method, a 



After the fifth moulting they measure 1 to i| inch. The 

 front of the army is now extended considerably. As 

 long as the sun is above the horizon the invaders march 

 on, running and leaping at the rate of more than 100 

 yards hourly. In the twelve days from May 21st to 

 June 2nd they have been known to cross ten miles. 



Their evolutions now become more interesting. Sup- 

 pose we are on a fallow field ; we perceive the long and 

 thick black line which marks the front of the invading 

 army. We hear a peculiar rustling like that of a flock 

 of sheep passing at a distance ; the army is at our feet 

 and passes rapidly, but it reaches a field of barley and 

 the pillage begins. It is wonderful to see the locusts 

 nimbly climbing the stems. Five, ten, and more may be 

 suspended to a single ear which bends beneath their 

 weight. A few strokes of their mandibles cut away the 

 protecting covering, and the tender grains are greedily 

 devoured. The rear-guard eat up the fallen fragments 



