99-i Parasitic Insects. 



avoided, especially in the moniiiiii: hours, tlie warble plague 

 may be combatted l)y a systeinatic destruction of the maggots. 

 This prophylactic measure, must, however, evidently be carried 

 out bj'- concerted efforts in affected regions. 



The right time for conuneneing the det^tnietion of the larvae is from the end 

 of April to the beginning of May, shortly before pasturing begins. At this time 

 the larvae are not so far develojted that they can crawl out from the swellings, 

 but most warble lumps already have an opening through which the larvse may 

 be removed. The procedure in getting rid of the larvaj is as follows: If the 

 pressing out of the larvte with the fingers cannot be accomplished, then they must 

 be pulled out with small, narrow forceps, or one punctures the end of the larva 

 lying near the hole with a crochet needle, whereupon the contents of the body of 

 the larva flows out, and the swelling may be evacuated by strong pressure with the 

 fingers. Larvge which cannot be removed even then may he left in the lumps where 

 they die and gradually suppurate out without usually disturbing the general health 

 of the animal. Exceptionally, however, a phlegmonous inflammation may develop 

 here, or more frequently a nettlerash arises some hours after the evacuation of 

 the warble lump. For the purpose of puncturing and pulling out the larva one 

 may employ a needle supplied with a small barb (after the nature of the crochet 

 needle). The dilatation of the opening of the warble lump with a knife should 

 only be undertaken by a veterinary surgeon. The last named procedure has now 

 and then been followed by very distressing phlegmons (Schmidt). During pasturing, 

 up to about July 1 the animals should be examined about every 14 days for newly 

 arising warble lumps, and any larvae present must be removed at the same time. 

 The removal of the larva^ is done in the stable or yard if possible. 



Closing of the openings of the swellings with heavy oil or tar and the use 

 of ointments only kill a part of the larvae; the procedure is therefore not suitable 

 for combatting the pests. But the effect of removing the larvae is supported by 

 suitable care of birds which destroy the larvae and the warble flies; such birds are 

 the starling, jackdaw, hoopoo, thrush, red-start, wagtail and titmouse (Strose). 



In Denmark some communities engage persons specially for the purpose of 

 removing the larvae. These examine the herds in their care from 4 to 6 times in 

 spring and early summer, and if warbles are present destroy the larvje with small 

 steel pincers. In Germany the procedure is also customary in various parts of the 

 country and in the Grand Duchy of Oldenburg the intention is to enforce its practice 

 by law. 



The larvae of other hot flies reside within the body, for instance the 

 larvaB of CEstrus ovis in sheep in the cavities of the facial bones (see 

 page 21), the larvge of Gastrophilus equi, especially in the stomach 

 of the horse (see page 452), the larvae of Gastrophilus peconnn, G. 

 hfemorrhoidalis and of G. nasalis, also in the stomach or duodenum of 

 the horse (the larva? of G. pecorum also in cattle), (see page 453). The 

 flies annoy the large domestic animals only when laying their eggs. 



According to Railliet the larva? of Ochromyia anthropophaga live 

 under the skin of the dog, and cause lentil-seized and painful nodules on 

 the tail, on the ears and the feet. 



Literature. Jost, Ilypoderma bovis, Diss. Leipzig, 1907 (Lit.). — Ostertag, 

 Z. f. Flhg., 1906, XVI, 407.— Eips, Z. f. Vk., 1909, 138.— Strose, Arb. d. G.-A., 

 1910, XXXIV, 41 (Lit.).— Villemoes, Z. f. Flhyg., 1906, XIV, 226. 



(c) Pupipara. The Hippobosca equina occurs frequently, 

 and is a brown fly 8 mm. long, with yellow head, three yellow 

 points on the breast, and longish rounded wings. It annoys 

 horses in summer, and exceptionally also cattle and dogs, by 

 settling in the region of the rectum and vagina, as well as on 

 the thin skin on the inner surface of the thighs. 



To this class also belongs the Melophagus ovinus (sheep 



