189 



pupal stage varies from two to several weeks according to the season. 

 The shortest life-cycle observed occupied one month. Detailed 

 descriptions of the various stages of this beetle are given. 



VON Ihering (R.). Observacoes sobre a Mariposa Mi/elobia smerintha, 

 Htibner, em Sao Paolo. [Observations on the Moth, Myelohia 

 smerintha, Hiibn., in Sao Paolo.] — Physis, Buenos Aires, iii, no. 13, 

 17th March 1917, pp. 60-68. [Received 7th March 1918.] 



The Pyralid, Myelobia smerintha, Hb., is well known in Sao Paolo, 

 Santos and Rio de Janeiro as a nocturnal plague in the to'^Tis, which 

 are invaded by swarms of the moths for about a week at a time. 

 As the adults are strongly attracted to lights, an apparatus for catching 

 them is fixed to the street-lamps and by this means some 855 moths 

 have been caught within the space of four hours. The larvae, which 

 incidentally have been proved to be edible and nutritious and 

 are considered a delicacy by many native tribes, live in the stems 

 of various Brazilian canes. In the course of his observations, the 

 author has found many insects and other Arthropods inhabiting the 

 nodes of these canes ; in particular a cane of the genus Chusquea 

 was found to harbour two species of Pentatomid bugs that apparently 

 pass the whole of their adult life in the canes, the entrance holes 

 frequently being too small for any but quite young larvae to penetrate. 

 The scale, Ripersia taquarae, Hempel, is also found among the frass 

 formed within punctured canes. 



Myelobia smerintha is found in large numbers in a cane which has 

 been identified as Merostachys clausseni var. mollior. Most varieties 

 of cane are largely adapted to agricultural uses and this one in par- 

 ticular is very valuable for making baskets, hampers, etc. In the 

 years when this cane blooms it dries up and dies, and it is only after 

 a long interval that it springs up again in the same place. The 

 flowering of the cane, which only occurs once in several years, is 

 apparently determined by prolonged droughts, and occasionally by 

 other climatic factors that stimulate the plant to perpetuate itself 

 by seeding at a time when general conditions are unfavourable for 

 its propagation by rhizomes. In all probability a similar reaction 

 occurs when the larvae invade the cane stalks, causing damage which 

 would prove fatal to the plant ; this would explain the fact that the 

 emergence of M. smerintha has as yet only been observed in flowering 

 canes. Eggs are deposited in large quantities on the leaves of garden 

 plants, for preference on the large leaves of Agave americana, and 

 hatch in a Httle over a week. The larvae from these, not finding 

 a suitable environment, descend by silken threads presumably in 

 search of their normal food-plants. From these observations it is 

 concluded that imder normal circmnstances the female oviposits 

 on the upper parts of the canes and the resulting larvae then descend 

 by threads until they reach a suitable intemode, the preference 

 apparently being for those that are three feet or more above the ground 

 level. Probably the larva then bores its entrance-hole, and having 

 entered the cane it seals the opening up with a silken web and feeds 

 upon the internal tissues, a large amount of frass and residue forming 

 at the base of the internode. In spite of this, the internodes inhabited 

 by a larva frequently appear to be intact, and sometimes have to 



