Marvels of Insect Life, 



the female affected the hairs of one antenna of the male more than those of the 

 other, but by altering the position of its head until both antennae were evidently 

 affected the male knew in \\hich direction to flv, and was bv this means able to 

 guide himself to within 5^ of the direction of the female. 



In addition to the organs named, others of a special sense have been discovered 

 at or near the base of the wings in flies, beetles, butterflies 

 and moths, dragon-flies, and grasshoppers, with a trace of 

 them in bugs. These have been variously considered organs 

 of smell and hearing. In the two-winged flies there are the 

 rudiments of a second pair of wings, known as halteres or 

 balancers. At the base of the halteres there is a number of 

 small bladders arranged in four groups, to each of which 

 extends a branch of a large nerve — after the optic nerve, the 

 largest in the Insect. Each of these bladders is perforated, 

 and contains a minute hair. It is thought that these sense 

 organs allow the perception of movements which the halteres 

 perform, and which enable the flv to direct its course. 



Powder- wings. 



There are some common Insects that seem doomed to 

 remain unknown not only to the general public, but to the 

 enthusiastic entomologist also. Among these are the aleurodes, 

 or powder-wings, a name given to them because their wings 

 instead of being covered with microscopic scales, as in the 

 butterflies and moths, are coated with a delicate powder very 

 like flour for fineness. On reference to our photographs of 

 several species that may be found on the under surface of 

 leaves, they will be seen to have a very close likeness to a 

 small moth. Indeed, the great Linnaeus actually included 

 these Insects as moths in his natural system of classification. 

 Other great men followed " the iUustrious Swede," and it 

 remained for Latrielle in 1793 to show that these Insects 

 had near affinity to the plant-lice, among which he placed 

 them. Later investigators, for good reasons, have removed 

 them from that family, though allowing them to remain in the 

 same order ^ as the plant-lice and the scale- Insects. To the last- 

 named, they are more nearly akin than to any other family. 



One of the reasons why so few students of Insect life 

 have paid any attention to this group - is to be found, no 

 doubt, in their small size, and in the difiiculty — in some 

 cases the impossibility — of distinguishing between the species 

 in their winged condition. The wings are always white or pale yellow, spotk-ss or with 

 indefinite darker marks, reminding one of the finger-and-thumb mark on the sides of the 

 haddock. It is in the earlier stages that we find differences of form, colour, t)rnamenta- 

 tion, and food-i:>lant, that enable us the b(>ttt'r to distinguish between the species. 



'■ Honiopteni. ' AlcurodiihL'. 



Photo hy\ [J. J. Ward, F.E.S. 



Tip of Moth's Antenna. 



The extremity of an antenna front 

 the male tii^er - moth is shown 

 magnified twenty-five times. Each 

 branch is tipped with a long hair, 

 which is apparently sensitive to 

 sounds and odours. 



