770 



T A B A N I D JE. 



some the body is short and thick, in others long and 

 depressed, and in a few the abdomen is very slender 

 at the base, and clubbed at the end ; the legs in some 

 are very slender, whilst in others the hinder femura 

 are thickened and toothed, and the tibiae curved. 

 The flight of these insects is also varied according to 

 the species. Many of these insects delight to select 

 some quiet warm spot in the open part of a wood or 

 garden, where they may be seen hovering for a great 

 length of time without shitting an inch from the spot, 

 although their wings are in such rapid motion that 

 they can scarcely be perceived. No sooner, how- 

 ever, are they alarmed or disturbed by the approach 

 of some other fly, than they dart off with the quick- 

 ness of lightning, returning again, however, in a very 

 short time to the very same spot. In like manner 

 they will select a leaf or a stone, from which they 

 will make long flights, returning again to the identical 

 situation. 



There is considerable diversity in the economy of 

 these flie?. Although the observations hitherto made 

 upon their habits have been but few in number, it has 

 been ascertained that their eggs are deposited in the 

 earth, in manure, in rotten wood, in the bulbs of cili- 

 aceous plants, in the nests of humble-bees and wasps, 

 on the leaves and stems of plants, in putrescent mat- 

 ters, and in water. The larvae hare the head fleshy 

 and of a variable form ; when full grown they do not 

 throw off the outer skin, which becomes a covering 

 for the pupa. 



The number of species comprised in this family is 

 very considerable ; the genera are, Ceria, Callicera, 

 Chymophila, Aphrites, Ceratophyla, Ckrysotoxum, Psa- 

 rus, Mlctcmyia, Volucella, Temnocera, Sericomyia, 

 Criorhina, Mallota, EristaUs, JDidea, Platynochaeta, 

 Helophilus, Priomera, Palpades, Merodon, Tropidia, 

 Senogaster, Xylota, Brachypalpus, Syritta, Eumerus, 

 JRhingia, Graptomyza, Brachyopa, Pelecocera, Milesia, 

 Syrphus, Doros, Spluerophoria, Ocyptamus, Cheilosia, 

 Chrysogaster, Orthoneura, and Paragus. The most 

 interesting of these genera are described in their 

 places in alphabetical order. 



The genus Syrphus is distinguished by having the 

 abdomen narrowed from the base to the extremity ; 

 the frontal projection of the head is short, the wings 

 are apart when at rest, and the- posterior margin of 

 the exterior cell of the wing is nearly straight, or but 

 little sinuated. The larvae of this genus feed upon 

 plant-lice, and it is very interesting to observe the 

 carefulness with which the female Syrphus flies around 

 the twigs of various garden shrubs, inspecting each 

 minutely, for the purpose of discovering whether 

 there are any of the Aphides upon the plant. In case 

 any are discovered, the insect, still remaining on the 

 wing, turns herself round and deposits an egg in the 

 midst of them, attaching it to the twig or leaf ; from 

 this egg an unsightly grub, without legs, is hatched, 

 which is no sooner born than it commences its vora- 

 cious attacks upon the insects in the midst of which 

 it finds itself ; destitute of eyes, it gropes about with 

 the extremity of the body, until it feels one of its 

 luckless victims, which it immediately seizes upon, by 

 means of the acute points with which its mouth is 

 armed, and raises it aloft in the air, holding it in that 

 situation until it has completely extracted all the 

 fluid from its body, and then casts it away ; it then 

 proceeds in the same manner, having little occasion 

 to move from the spot, and consequently being desti- 

 tute of legs. When it has attained its full size it 



fastens itself by the hinder part of the body to the 

 twig ; it then contracts its body, which by degrees 

 assumes an oval form without casting the outer skin, 

 which serves as an envelop for the inclosed pupa. 

 The perfect insect makes its appearance in a very 

 short time, having lost all the voracious propensities 

 of its former state. We have found it very service- 

 able to introduce the larvae of these insects amongst 

 the Aphides which have infested a choice plant, and 

 which they have cleared in a very short time. There 

 are about thirty British species of this genus. 



TABANID^E (Leach). A family of dipterous 

 insects belonging to the division Brachocera, and 

 forming the subdivision Hcxachata (see DIPTERA). 

 These are large two-winged flies, well known for their 

 tormenting powers in attacking horses and cows, by 

 sucking their blood by means of their powerful pro- 

 boscis, composed, as the subdivisional name indicates, 

 of six lancet-like organs, inclosed in the ordinary 

 fleshy rostrum, which is terminated by two large 

 fleshy lips. The eyes are large, especially in the 

 males, and the antennas have the third joint large 

 and crescent-shaped, terminated by several smaller 

 articulations. A figure of the head of one of the 

 species of the genus Tabanus, with all the parts of 

 the mouth disengaged from the rostrum, is given in 

 the article DIPTERA, and the details of the mouth in 

 the same genus are given in detached figures in the 

 article INSECT (vol. ii. p. 850, fig. 88). These insects 

 have often been described under the name of gadflies. 

 The body is seldom very hirsute ; the head is of the 

 width of the thorax, nearly hemispherical, and covered, 

 except a narrow space, especially in the males, by 

 two large eyes, which, in some of the species, exhibit 

 the most brilliant hues when alive, the colours being 

 arranged in bands. The wings are extended hori- 

 zontally on each side of the body when at rest ; the 

 winglets are large, and nearly conceal the halteres ; 

 the abdomen is triangular and depressed ; and the 

 tarsi are terminated by three pulvilli. 



From the comparatively large size of these insects, 

 they are capable of inflicting very great pain both 

 upon men and beasts of the fields. Their flight is 

 noiseless, although some make a buzzing sound when 

 on the wing ; and often, whilst walking in the fields 

 and woods, we have been made to start by the sud- 

 den pain produced by one of these insects which had 

 settled upon the naked hand. Their pertinacity is 

 also so great that they cannot be driven away. The 

 horse lashes with his tail and throws about his head, 

 but all in vain ; the Tabanus retains its seat, and at 

 length, when satiated, the fly desists ; and then the sides 

 of its victim may be seen trickling down with blood 

 from the wounds made by the insect. It is supposed 

 that the redoubtable Zimb of Arabia, or Tsaltsalya of 

 Bruce, is a species of this group of flies. The Taba- 

 nus maroccanus of Fabricius attacks the camel, which, 

 according to M. Desfontaines, is sometimes entirely 

 covered with these troublesome creatures. It is a 

 curious fact that the females alone are endowed with 

 these blood-thirsty qualities, the males frequenting 

 flowers. 



The larvae of Tabanus bovinus reside in the ground. 

 They are long, cylindrical, narrowed towards the 

 head, which is small, and armed with two hooks. 

 The segments of the body, twelve in number, have 

 elevated transverse ridges. The pupae are naked, 

 nearly cylindrical, with two tubercles in front, the 



