387 



entirely destroyed down to the roots, and one larva is able to de- 

 stroy several sueli before becoming- mature. In instances where several 

 larvre had been at work upon one plant, this was often destroyed com- 

 pletely; not a single healthy cane was left, and freciuently four or five 

 parallel tunnels could be found witliin one stalk. In rare cases the 

 whole inside of the cane is a complete mass of fibers. 



During the time of my visit the most of the Inrvie wen^ nearly full 

 grown, although some were found measuring not more than one-half 

 inch in length. The chrysalids were not so numerous, and some of 

 these had already hatched. From these meager observations alone it 

 can not be said witli any certainty how many broods there are annually, 

 yet it is almost safe to say not more than two, allowing for irregularities 

 in this warm climate. All the large larv;e fOund were no doubt of the 

 first brood or from larvae that had hibernated and i)ui)atcd, say, al)out 

 October and November. The dnration of the pupa state, judging 

 from specimens bred in confinement, is extienu'ly short, only from ten 

 to twelve days, varying, however, with tlie temperature. During 

 spring it may even take twice this length. 



Two species of parasites were observed to prej' upon this insect. 

 The first is a species of Microgaster, which destroys fully one half of 

 the larvje, and from 50 to 80 specimens were bred from single individ- 

 ual larvje. No doubt these little parasites are in constant sear(;h for 

 their hosts, and not only deposit their eggs within such larvse as have 

 left their tunnels and are searching for new places, but also enter the 

 open holes in the plant in search of them. All of the bred specimens 

 were from grown or nearly grown larvse. The larvic of the parasites, 

 as is well known, leave their host when full grown and spin a white 

 silken cocoon on the outside and together, generally in the place pre- 

 pared by the larv« for pupation, and in four or five days, as repeatedly 

 observed during January, the active little insects emerge to begin 

 their useful work anew. This is certainly the most beneficial agent in 

 keeping this serious pest to cane-growers in check, and without which 

 it would not be possible to grow this crop successfull3^ I might also 

 prove its usefulness upon other and closely-related species in distant 

 countries if an opportunity were given. 



We may safely say that the whole life cycle of this parasite, from agg to 

 imago, will not take more than fifteen to eighteen days during the warm 

 months, and that about twelve broods may be expected during the year 

 to two of the moth. Thus it will be seen of what infinite value such 

 minute insects are. 



The second si)ecies is a Chalcidid and parasitic upon the chrysalis of 

 the moth. This also is a very interesting little insect. The chrysalis 

 of the moth is stung by the parent parasite, and as many eggs are laid 

 within as will entirely fill the shell with the larvie as these become full 

 grown. They then pupate, both within and without, making similar 

 cocoons of the foregoing, and in due time the mature insects,which are 



