Celery and Chrysanthemum Leaf-Miners. 



105 



the appearance of the leaves of which various parts are destroyed, 

 by shading the shriveled part ; but it is difficult, without the 

 assistance of colour, to convey the real appearance of the leaf. 



On examining the leaves, and opening part of the withered 

 portion of the leaf (Jig. 21. b: a, withered part of a leaf; b, 

 portion of the withered part raised up, to show the state of 

 the interior, c), the interior was found to be quite destitute 

 of pulp, and to contain one or several small green grubs of a 

 dipterous insect, which had eaten all the interior parenchyma, 

 leaving only the two surfaces of the leaf entire, but very thin. 

 I found as many as three, four, or even five, in a single leaf, in 

 which case I noticed that they were occasionally of different 

 sizes. The appearance of these larvas under a magnifying glass 

 (Jig. 21. c) is very similar to that of the onion fly, and many 

 other dipterous larvae belonging to the herbivorous species of 

 .Muscidae ; but the colour is delicate green, the sides of the 

 body very transparent and glassy, and the alimentary canal per- 

 ceivable down the back by its dark colour ; the head and anterior 

 segments of the body are gradually attenuated, and terminate in 

 a point. When these larvae are fully grown, they quit the leaves 

 and descend into the ground, where they gradually shortly 

 afterwards appear to lose all vitality, their form becoming shorter 

 and oval, with the segments distinct, and terminated at each end 

 by two obtuse points (Jig. 21. : d, natural size; d, magnified). 

 The outer skin of the larva is not cast off", but becomes a 

 hardened pellicle, within which the real pupa is not to be found. 

 In this state the insect remains buried in the ground until the 

 following spring, when the warmth gives birth to the imago, 

 which is one of the most beautiful of our species of two-winged 

 flies; which, after throwing off its pupa skin, and bursting 

 through the hardened pellicle of the larva, crawls to the surface 

 of the ground, and then takes flight. It belongs to the 



Order, Diptera Linnceus. 



Tribe, Myodariae Rob. Desvoidy. (Family, iliuscidge Leach.') 

 Subfamily, Tephritides. 



Genus, Tephritis Latreille. Trypeta Meigen. 

 Subgenus, Euleia Walker (from the smoothness of the body). 

 Species, Tephritis (Euleia) onopordinis Fabricius. 



Syn., Tephritis centaurese Fabr, Meigen. (Fig. 21. e, natural size; Fig. 22. f 

 magnified. 



