5*5 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



[ January 15, 1874. 



of one eBculent is quite enough to show the necessity for 

 wholesome and wholesale excision in the compilation of trade 

 lists, and care on the part of the trade and growers generally 

 not to be hastily caught by glowing descriptions from self- 

 dubbed raisers of so-called new varieties, and by flashy testi- 

 monials from their friends. On another occasion we may have 

 a word to say with regard to one or two other of our garden 

 vegetables. — {Irish Farmers' Gazette.) 



THE BEAUTIFUL AND USEFUL INSECTS OF 

 OUR GARDENS.— No. 14. 



"Delivee me from my friends, and I will take care of my 

 enemies," was the remark of a somewhat cynical philosopher, 

 wide-awake to the fact that one has often more to dread from 

 those whose aspect is friendly to appearance than from open 

 opponents. In the pursuit of horticulture it is not always 

 easy to distinguish friends from foes among the insect tribes, 

 and there is a pretty general feeling that insects found crawl- 

 ing or flying in gardens are rather more hkely to be nuisances 

 than benefits, and their fate is correspondent to the belief, 

 often by design, sometimes by accident ; for, unquestionably, 

 when using freely certain famous " compounds," " insect- 

 destroyers," and so forth, the gardener blends friend and foe 

 in one undistinguished mass. And it is just possible that in 

 some instances the killing of a predatory insect may be attended 

 with the death of so many of its particular parasite that matters 

 are about equally balanced as to results. The march of in- 

 telligence is doing much, however, for the gardener, in leading 

 him to regard the insect world in a very different way from 

 what it was viewed by his predecessor, say in the good old 

 times of George III. In the case of the agriculturist the pro- 

 gress is slower ; but one hopes by-and-by the few labourers 

 that Mr. Arch and his friends intend to leave us will do some 

 credit to the advanced civilisation of the nineteenth century, 

 unless, indeed, they are over-petted. Meanwhile not only 

 Hodge, but his master, seem slow to renounce ancient pre- 

 judices ; vainly have I of late appealed against the shooting- 

 down of rooks in these winter months, because of the mischief 

 they are supposed to have done in Turnip fields. A reference 

 to the " grub " as the real enemy of the Turnip crop does not 

 alter the case in the bucolic mind ; for it stands thus : Admitted 

 the grab ; well, does not the rook, in its searches after the 

 insect, unearth the Turnip, and thus finish-off the destruction 

 commenced by the invisible enemy ? Whereas, for the most 

 part, so sagacious are rooks that it will be found they attack 

 those Turnips which would hardly ever come to any good, 

 though they may now and then root-up sound ones ; also, I 

 believe the species may be in a great measure exonerated from 

 the accusations brought against it with reference to grass and 

 Potato fields. 



Returning to our more immediate subject, I would here note 

 that there are a good many species of the Dipterous order that 

 are of service to us by seizing and devouring other insects of 

 various orders, though they do not diminish our enemies so 

 effectually as do the larva; of the Syrphidas and Tachinida?. 

 i'ew, if any, of the flies are useful to us in both the larval 

 and winged condition ; and the flies, so agile on the wing in 

 summer, and eager in pursuit of their prey, are mostly feeding 

 quietly in the winter on refuse of an animal or vegetable 

 nature, or, in a few instances, on the roots of plants. The 

 transformations of these are as yet imperfectly known, being 

 difiicult to observe. The majority of the flies friendly to us 

 belong to the section Brachycera — the " short-horns," in fact, 

 which also includes some of the greatest enemies of man and 

 domestic animals. Among the latter the Cleg, the Horse-fly, 

 and the Gad-fly are names of terror, and those belonging to 

 the genus Tabanus {tuj. 1) are remarkable for strength and 

 fierceness, with lustrous eyes of varied colours. Though these 

 attack cattle (at least, the female insects), it is believed they 

 also make other insects their prey ; but are more usually to be 

 seen on the wing in pastures and about woods, and not in 

 gardens. Flies of the genus Asilus, some of which are very 

 familiar objects, are common about roadsides, and occasional 

 visitants in gardens ; also, like the Tabaui, exceedingly active 

 and almost as ferocious as are the Dragon-flies ; worse in 

 character, possibly, as they are of a cannibal turn. 



Asilus crabroniformis (t'ltj. 2) is a handsome fly, well clad 

 with hairs of a tawny hue, except on the front of the abdomen, 

 where they are deep black. The wings are also of a golden 

 hue, and gleam in the sunshine when the insect buzzes 



over flowers, to which it frequently resorts for various pur- 

 poses. One object it has is to seize some insect so intent 

 upon honey that it is off its guard, and an Asilus may be seen 

 sweeping through the air with a bee in its grasp, being appa- 

 rently indifferent to the danger of being stung. A variety of 

 insects, however, furnish food to the Asiii ; and these flies also 

 make caterpillars their prey, and as they do not devour their 

 victims, but only suck then- juices, one fly may in its lifetime- 

 kill many insects. The larvre of the Asili feed under cover^ 

 either on decaying roots and stems of plants, or in holes in 

 trees which have been excavated by others. A curious pecu- 

 liarity possessed by the fly is the three-padded foot, by means 

 of which the hold upon whatever is seized is rendered more 

 tenacious. Recently, at W'oolacombe, North Devon, Mr. F. 

 Smith observed a silvery species of Asilus, which afterwards 

 proved to be A. albiceps, eager in the pursuit of grasshoppers, 

 numerous on the grassy slope where the fly occurred. A 

 species of feebler flight of the genus Leptis (L. scolopacea) 

 furnishes another example of the three-padded foot to those 



Fig. 1.— Tatonus antmnnaliB.'' 



Fig. 2. — Asilus crabroniformis.* 



desirous of examining it ; this being common in shady spots, 

 as well as in gardens. The thorax is striped, the abdomen 

 spotted in the centre, and the wings edged with grey or brown. 

 The larva; in this family are Uttle known, only of one foreign 

 species it is stated that it is parasitic in habit, and obtains the 

 small insects it feeds on by constructing pitfalls in sandy 

 earth. This is more notable, because the great bulk of tho 

 larva; of flies (rtilgo, maggots) display very little sagacity, 

 and do not seem capable of much in the way of constructive 

 art beyond the making of a cocoon. 



Amongst the Empidic tho same habit prevails as we find in 

 the gnat tribes. The males are harmless, and employ them- 

 selves in sucking honey, while the females are predacious. The 

 tongue in these flies is long, and its appearance has led to 

 their being designated Snipe-flies ; their legs also are of good 

 length, and serve to embrace the moths and flies which the 

 Empida; seize and fly along with. Empis tessellata is seen 

 through the spring and summer, so that it must either be 

 more long-lived than most flies, or else there must be a suc- 

 cession of broods. In this species the thorax is grey, streaked, 

 with black, the legs are spiny, and the wings dusky in hue. 

 The destruction of multitudes of the small moths of the Tortrix 

 family is effected by this and other species of Empis, and, as 

 is well known, many of these moths, as parents of leaf-rolling 

 and mining caterpillars, are exceedingly annoying to the gar- 

 dener. In some seasons it will be observed that these "flies 



From Cassell'B edition of Figuier's " Insect ■World." 



