| Show mans never ending war on his insect enemies one war that never ceases Is that waged by insects upon man every year insects cost the human rare race millions upon millions ot of dollars by their destruct destruction il on of growing crops and stored harvests and they kill or malm thousands of human beings by spreading disease science is 11 constantly engaged in n investigating new means of keeping insect foes at hay bay and wonderful work lias has been done the stamping out of nia malaria larla in large areas once almost uninhabitable and the checking of the spread of sleeping sickness are examples of what has been accomplished now comes news of a discovery which may open up entirely new lines of attack on oil insect pests for a long iong time past a young australian scientist dr F 0 ITol daway lit lias been endeavoring endea oring to find ft a yay vay of dealing with the flour beetle which does nn an enormous amount of damage lie ile has found that eliat the proportion of grubs gruba that turn into males and females can be controlled olied by regulating their food starve a hundred gm grubs for one lay day and the majo majority pity will develop into male beetles now the female beetle may I 1 lay ay thousands of eggs if therefore lie lias has found a moans nicais of decreasing the nt number niber of females the bettle pest may be kept down SIm similar Ilir principles of sex control may be found applicable to other insect enemies or of man mail |
