46 BITINO AND NOXIOUS INSECTS OTUF.H THAN MOSQl'ITOKS 



7. Tlif l)fst giiidi' to tlic ogfj;s is tlio presence of ilcail locusts lyiii^ on the ground. 

 S, Tlu- igg clusters iire usually found iit a depth of two inches. 

 9. Flights and egg-luying may be expected after the rains. 



10. Eggs, if not disturbed, are not destroyed by being covered with water. They will 

 hatcli out when the submersion is over. 



11. A single egg soinewhut resembles a grain of wheat in shape. The eggs in a cluster 

 arc arranged in rows with grooves between them. 



12. The numlxT of eggs laid by a well developed locust varies from 100 to IfjO. 



13. The time of hutching varies from IT) days to several months, (h-pending on climatic 

 condition and soil temperature. 



11. WIkii tlic cg^s have been laid, a few well-grown locusts are said to remain behind 

 to guide the young ones. Infornmtion is required on this point, and also as to tin- liiigth of 

 time egg-laying lasts. In some places this is as much as (i or 8 weeks in the same locality. 



If). The young locusts are called " Hoppers." They roo.st at night on grass tufts, 

 bushes, boughs, etc., and descend to the gnmnil before sunrise. 



1(5. The "hopper" stage is said to last about 50 days. It terminates by tlic j)roduction 

 of the adult winged insect, the " hopper " shedding a scale or sludl wliidi remains on tlie 

 twig or leaf wliere the transformation takes place and which looks very like a live locust. 



17. Locusts only migrate on account of insufliciency of food. 



Dkstuuctio'n 



The means to be employed niay be (lassed under five divisions: — 

 ((f) Encouragement of natural agencies. 

 (A) Destruction of the eggs. 



(<■) Destruction of the young or unfledged locusts. 

 ((/) Destruction of the mature or winged insects. 

 (e) Preventive measures. 

 (a) Eiicoiirdoi'iiieiit ofWiifiiriil Ant'iicii'.i. — In the Sudan all tiiat coidd be done in this 

 direction would be to protect the smaller birds. The destruction of hawks is advisable for 

 this purpose. Fowls and turkeys are useful foes. It is wortli noting tliat the large monitor 

 lizards (U «/•«««) feed greedily on locusts. 



(A) Dcslritctioii of till' Emix. — This is usually accomplished in five ways: — 

 1. Harrowing. 4. Tramping. 



'J. Ploughing or spading. 5. Collecting. 



3. Irrigation. 



2. In the Sudan ploughing to a depth of 2 inches might be tried in certain localities. 



3. Irrigation is only of use when the land can be Hooded for a few days, just at the time 

 when the bulk of the eggs are hatching. 



4. Turning animals loose on infected land is a useful method. Cattle, horses, sheep and 

 goats mav be used in this wav in any area where they can be confine<l in smne measure. 



5. Collecting is probaiily the best jilan in a country like the Sudan. Huying eggs at 

 16 to 30 piastres an oke has been foinid very effective in Cyprus and Tunis, and might be 

 tried. In any case it would lead to u.seful information being obtained from native sources. 



The proper wav to collect eggs, ('specially if the soil is light and the eggs are numerous, 

 is to slice off about an inch of the surface by trowel or spade, remove the egg-laden earth to 



