14. Juni 1913. 



v^ ^^\ 



No. 12. 



XXVIII. Jahrgang. 



ocietas entomologica 



Organ für den internationalen Entomologen =Verein. 



Journal de la Société entomologique internationale. 



Journal of the International Entomological Society. 



„Vereinigt mit Entomologischer Rundschau und Insektenbörse." 



B 



Gegründet i886 von Friis Rühl, fortgeführt von seinen Erben unter Mitwirkung bedeutender Entomologen und hervorragender Fachleute. 



Toute la correspondance scientifique et 

 les contributions originales sont à envoyer 

 aux Héritiers de Mr. Fritz Rühl à Zu- 

 rich V. Pour toutes les autres communi- 

 cations, payements etc. s'adresser à Ver- 

 lag des Seitz'schen Werkes (Alfred 

 Kernen), Stuttgart, Poststr. 7. 



Aile wissenschaftlichen Mitteilungen und 

 Originalbeiträge sind an Herrn Fritz 

 Rühl's Erben in Zürich V zu richten, 

 geschäftliche Mitteilungen, Zahlungen etc. 

 dagegen direkt an den Verlag des Seitz- 

 schen Werkes (Alfred Kernen), Stutt- 

 gart, Poststr. 7. 



Any scientific correspondence and origi- 

 nal contributions to be addressed to Mr. 

 Fritz Rühl's Heirs in Zürich V. All 

 other communications, payments etc. to be 

 sent to Verlag des Seitz'schen \A?erkes 

 (Alfred Kernen), Stuttgart, Poststr. 7. 



Die Societas entomologica erscheint gemeinsam mit der Entomologischen Rundschau und der Insektenbörse. 



Abonnementspreis der 3 vereinigten Zeitschriften Mk. 1..50 vierteljährlich bei postfreier Zusendung innerhalb Deutschland und 



Oesterreich, fürs Ausland Portozuschlag — 50 Pfennig vierteljährlich. Erfüllungsort beiderseits Stuttgart. 



57. 28 Locusta: 16. 5 



îfotes Oll Plague of Locusts iu North 



(Jueenslaud aud its Kelatiou to Sugar 



Caue. 



By A. A. Girault, Nelson. Cairns. 



At Mossman, North Queensland on March 22, 

 1912, the adults of this sf)ecies of the fu'st generation 

 (parents of a possible second geiaeration) were excee- 

 dingly abundant fljàng about continiialty during 

 the day; taking position in a field of sugar cane, 

 for instance, and looking over it, one could see them 

 flying across it in all directions, not at all unlike 

 birds; these flying adults were not in swarms but 

 several hundred could be seen at any one time, aU 

 single. Along strips of grass, however, they were 

 much more abundant, occurring here and there in 

 densely packed masses of about ten to fifteen square 

 yards, roughly. All of these individuals were not 

 adult, however; at least half of them were in the 

 last larval or nymphal stage and a few in the penul- 

 timate larval stage. Many were observed in their 

 final ecdysis and on one individual undergoing this 

 process these notes were made : This individual was 

 observed hanging head downward from a blade of 

 grass, a foot above the ground; its skin had been 

 shed down to the last legs. The shed skin firmly 

 grasped the grass blade by the intermediate and 

 posterior legs. The wings had been freed but were 

 still shrivelled and curled. This was at 10. 40 a. m. 

 Five minutes later, the ecdysis was comf)leted and the 

 soft adult attempted to turn about by grasping the 

 shed skin; in this it faUed and fell about eight inches, 

 taking hold of some grass, its head upward. The 

 wings were perfect by 11 a. m., their markings dimly 

 perceptible along the proximal half. During the next 

 quarter hour no change in coloration occm'red. 



Thus, at Mossman toward the end of March, the 

 first generation since the migration was just coming 

 to maturity. Oviposition had not commenced. 



On March 26, 1912 at Nelson I noticed that the 

 adult locusts of the first generation were also very 

 numerous ; on April 1 , I could find no young but as I 

 sat in the laboratory building on the outskirts of 

 Nelson I could hear the constant cheking sound made 

 by the adults when fl;\dng about. At this time, injurj^ 

 to cane was noticeable and rather extensive, apparently 

 all done by these adults of the fhst generation, now 

 mature. If one took position in the centre of a field 

 of infested cane, standing up and looking over it 

 one could not see that aiiything was Awong but stoo- 

 ping down and looking along a row, a network of bare 

 leaves was presented. This was an average condition 

 for rows in some fields. Only the lower leaves had 

 been attacked; these were usually stripped bare to 

 the groove-like midrib (more rarely only partially 

 and irregularly eaten to the midrib) but sometimes 

 the whole of the outer, blade portion of the leaf had 

 been eaten away, leaving but a part of the midrib 

 which was sharpened toward its end as if with a knife. 

 In other cases, only long rectaiigles had been eaten 

 from the margin of the leaves. The elliptical, white 

 pellets of excrement, resembhng pieces of dried wood 

 pith were scattered over the soil around the base of 

 each plant while the leaf-axUs each contained a little 

 pUe of it. Although thus extensively eaten, the 

 general healthy appearance of the plants was not at 

 all affected; the plants were too old and vigorous to 

 show the drain and soon recovered. 



I have frequently seen hens chasing the adults of this 

 locust but only on one occasion did I see the insect 

 caught; to aU appearances, it was then hurriedly 

 engulphed. Sometimes the locusts commence to fly 

 scatteringly but aU in the same direction and one may 

 see them passing for an hour or more during these 

 flights. On April 5 at Nelson an unorganized flight 

 of this kind was observed at tAvo o'clock in the after- 

 noon in an east by south direction; soon thereafter 

 rain came up from behind, overtook the locusts but 

 they continued nevertheless; they were about forty 



r.v., 



