A REVISION OF THE GENUS LOCUSTA, L. 151 



It is quite obvious from this definition that migratorioides presents no new features 

 as compared with migratoria, but it seems to be in all the chief characters 

 merely a further modification of migratoria in the direction opposite to danica. 

 Unfortunately the material of migratorioides now at my disposal is rather scanty, 

 and the extent of its variability remains uncertain. Still, there is in the British 

 Museum one female taken at Sarkwalla, Northern Territories, Gold Coast, 4-7. xi. 1915 

 [Dr. J. J. Simpson), which is in all respects intermediate between migratoria and 

 mis'ratorioides. 



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7 



Fig. 4. Lociista migratoria, ph. viigratorioides, Rch. & Frm., S from Lagos : A, head and pronotum 

 from above ; B, pronotum, side view ( X 3). 



The study of the male genitalia of migratorioides reveals no difference whatever 

 from the structure observed in danica and migratoria (fig. 7). 



As for the coloration of the larval stages, we have a good description of them 

 given by H. C. Pratt {I.e.) and from it, as well as from the study of the actual 

 specimens sent by Mr. Pratt to me in 1913, I was unable to find any reliable difference 

 between them and the larvae of migratoria. 



On the other hand, Mr. Pratt says in his paper that the coloration of the larvae 

 is not very constant and the green individuals occur alongside with the typically 

 coloured ones. The figures of the green and black adults given in his paper {I.e., 

 pi. XIV) certainly represent daniea. This is, then, an indication that the same inter- 

 relation exists between migratorioides and daniea as has been proved positively for 

 migratoria and daniea. A confirmation of the same fact I received not long ago, 

 when several specimens of locusts were sent from North Borneo to the Imperial 

 Bureau of Entomology for identification. They all proved to be migratorioides, but 

 as the lot was rather small, the Bureau asked for more material, and after several 

 months a new collection arrived, with a note that the specimens were taken singly 

 at the same spot as the swarms from which the first lot had been collected, and 

 represented the actual offsprmg of those swarms. All specimens in this second 

 lot are quite typical danica. 



One more example of the transformation of migratorioides into daniea I have found 

 in Dr. La Baume's paper on the African locusts.* In a reference to Dr. L. Sander's 

 bookf he discusses an invasion of locusts which took place at Misahohe, Togo, in 

 December 1893, while in March 1894 new larval swarms appeared at the same 

 locality, which Dr. Sander believed to be the direct progeny of the December swarms. 



* Die Afrikanischen Wanderheuschrecken. — Beih. zum Tropenpflanzer, xi, No. 2, 1910 

 p. 82, footnote 22. 



t Die Wanderheuschrecken und ihre Bekampfung in unseren Afrikanischen Kolonien. 

 Berlin, 1902. 



