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HARDWICKE'S SC1E N CE-GO SS 1 P. 



pounded by others, who think that, in some cases 

 at least, the resemblance may be protective, that 

 is to say, the Hornet Clearwing may escape certain 

 of its foes because it looks like the real hornet, 

 a dangerous insect to tackle. True, on the other 

 side, it might also be urged that the resemblance 

 might be a helpful resemblance to the carnivorous 

 hornet ; enabling that insect to steal upon other 

 insects as in the guise of a harmless moth ! And 

 with regard to the Clearwings, which so nearly 

 approximate in appearance to flies, it can scarcely 

 be averred that the moths are not in as much clanger 

 of being snapped up by a bird or insect foe when 

 thus resembling flies, as if they assumed the general 

 aspect of their brethren. That one may be mistaken 

 for the other on the wing I have abundant evidence, 

 as I have noticed a fly, a species of Asilus, I pre- 

 sume, that is particularly busy in gardens just at 

 the period when the Currant Clearwing {S. tipuli- 

 formis) comes forth, and which in appearance and 

 flight is similar, so as to deceive the observer. 

 Probably, the exceeding rarity of several of the 

 Clearwings is due to this ; they are passed as flies 

 by the entomologist, and some of them are scarcely 

 ever seen to alight, for when on the wing they pass 

 quickly from flower to [flower, and when they do 

 settle, it is in a place of concealment. The species 

 above named, and one or two others, are less timid, 

 and will settle on leaves in full view. 



" Nocturni," so far as these species are con- 

 cerned, is not a happy designation, for though 

 specimens have now and tben been taken at sugar 

 or flowers in the twilight, or later, their natural 

 time of flight is the day, aud they prefer sunshine 

 to dulness. Some species evidently are of sluggish 

 habit; our Hyde Park friend, S. cynipiformis, is 

 one not given to aerial excursions, aud I do not 

 believe the floral displays made in other parts of 

 the park succeed in tempting the insect from 

 its rather quiet habitat on the banks of the 

 Serpentine. June and July, it should be noted, 

 seem the months for the emergence of the perfect 

 insects of all the British Clearwings, and the flight, 

 as perceivable in the case of the commoner species, 

 lasts about a fortnight. Not that, as I think, 

 individuals live as long as that, but they appear 

 to come out in succession. Years ago (and it may 

 be so still) there used to be a keen competition 

 amongst the lads belonging to some dealers in 

 insects, who would be first on the spot to " collar " 

 the species referred to above, for the moths had 

 a fancy to quit the pupa at early morn, and as soon 

 as their wings were dry they very judiciously crept 

 down, and hid in the long grass. Hence this 

 species may often be sought and not found, though 

 you may feel sure it is about ; and even more hope- 

 less often is the search for S.formica>formis in an 

 osier plantation ; where you may beat, and beat, and 

 beat in vain. Collectors, wise in their generation, 

 carefully seek for the full-grown larva} of these and 



other species in April or May, and for the pupa; 

 a little farther on, and take Iheir chance of rearing 

 them. The duration of the caterpillar state is 

 variable ; in some of the species there is no doubt 

 that .the larva;, hatched in one autumn, live through 

 the next winter, and the one succeeding, so that the 

 round of existence occupies two years. Several 

 entomologists have observed this fact in the instance . 

 of S. apiformis ; and I have myself found, in the 

 early autumn, larva? of S. tipuliformis, of such pro- 

 portions as to preclude the idea that they had been 

 hatched during that summer. What is thus ascer- 

 tained about one gives us a clue to the history of 

 its allies ; but yet it is possible, that even in a 

 single species the economy varies from year to 

 year, and that in some seasons a part, or the whole 

 of a brocd, may come out in the next year after the 

 larvae hatched out. We arc still much in want of 

 information as to how mining larva; are affected by 

 changes of temperature, and by dry or damp seasons. 

 But, however, we may venture on the general con- 

 clusion, that what is conducive to the vigour of the 

 plant an insect makes its habitat, that is also help- 

 ful to the insect. 



All these larva;, as I have hinted, live unseen, 

 and therefore they are best known by their results ; 

 when reaching the pupa condition, in some cases 

 the insect is exposed to view, owing to its coming 

 to the surface of the substance in which it has been 

 reared, though usually the pupa contrives to have 

 a slight protective film of wood or bark. Hence, a 

 moiety of them are doubtless picked up by hungry 

 birds, always on the outlook for anything in insect 

 shape on the trunks or branches of trees that has 

 not the power of runniug away. Yet these pupa; 

 have the ability to move to some extent, as they 

 can wriggle up aud down the mines or passages 

 which the larva; have made, by the help of a series 

 of recurved hooks or points runniug along the 

 segments. From their mode of life, it is obvious 

 that these larva; — which in their maggot-like form 

 and hue do not remind us of lepidopterous larva? 

 — must be considered, on the whole, no friends to 

 vegetation. Of S. apifonnis, it has been strenu- 

 ously asserted that it only attacks poplars that are 

 in an unhealthy condition, therefore it may be 

 called a scavenger rather than a destroyer ; and 

 possibly this may be true of the species akin to 

 that which feeds in the osier (S. bembeciformis), 

 and of one or two more, certainly not of the majo- 

 rity. There have been those who have endeavoured 

 to show that the Currant and the Bed-belted Clear- 

 wings do no harm to currant-bushes, or to apple 

 and pear-trees, and I grant that occasionally there 

 may be an increase aud not a diminution in the 

 quantity of fruit borne. But as in the case of 

 stimuli resorted to by the human subject, the ulti- 

 mate result of these efforts to keep up the vitality 

 is a marked depression, and the issue of the 



