The development of the adult female lac cell (Horn. Sternorryncha)

4 láminasScale-insects, being inj urious to plant life, have been studied with a view to eliminate them. Lac, being a useful product, coccids producing it, are artificially propagated and an entomologist working on them has therefore to study them thoroughly. One problem, in lac cultivation is to determine, as quickly as possible, the stage of growth in which a colony of insects may be found. A low power magnification, under a dissecting binocular microscope, often suffices for the purpose. 'What has been done on this special problem is quite incidental. The life-cycle of any scale-insect can be broadly divided between its larval stages as one and the adult stage as the other. To distinguish among different larval stages, up to the last moult, enough has been published. Even here it was not certain, at first, if the female insect undergoes two or three moults. For example, according to Negi, the female lac insect becomes adult in its third stage, whereas an article in this journal has established that, the female moults thrice, and it is the fourth stage that represents the adult. Further the developing adult female has hitherto been characterized merely according to its age. Now there are two life cycles of the lac insect in North roughly one of 4 months and the other of 8: therefore to state that the insect was 2 or 3 nionths old, without further particulars, means next to nothing. Information required for deciding how a colony of lac insects is developing after fertilization has to be more definite which is being supplied by the present communication.Peer reviewe