LIBRARY *ATE PLANT ilQ^^-'O issued September 1931 (Revised) Revised July 1939 United States Department of Agriculture Bureau of Entomology and Plant Quarantine THE BROWN DOG TICK, WITH SUGGESTIONS FOR ITS CONTROL By F. C. Bishopp Investigations of Insects Affecting Man and Animals The brown dog tick (R hipice phnlus sanguin eus (Latr.)) is an import- ant pest of dogs. Vi/hile it is not known to carry any disease in this country except canine piroplasmosis , it breeds so rapidly that it causes a heavy drain on the vitality of the animals and is a source of great irri- tation to them. This tick is also an important household pest. Not in- frequently it becomes scattered by dogs throughout dv/ellings. v/here it sometimes appears in great numbers around baseboards, v/indow casings, curtains, and furniture. It seldom attaches to any other animal than the dog. The disease of dogs referred to above apparently is not wide- spread in the United States, This tick is normally an inhabitant of the warmer regions. It is now most troublesome in Texas and Florida, although it is spreading through the Southern States and occurs in many of the Northern States, where it has been introduced on dogs which have been in the South. Its spread is brought about mainly by the transportation of dogs from regions where ticks abound or from local services such as infested kennels and hospitals. This tick is essentially a domes+ic species. It does not occur in the woods or open country, as do mnT^y ticks, but is usually found con- centrated where dogs are kept. Life h istor y . — The females, v/her fully engorged, are about one-third of an inch in length and bluish grny. They release their hold on the dog and seek a hiding place near by. They have a strong tendency to crawl upward and hence are often found hidden in cracks in the roofs of kennels or in the ceilings of porches. In these hiding places they deposit from 1,000 to 3,000 eggs, which hatch in from 19 to 60 days into minute, active, 6-legged seed ticks. When opportunity offers, these ticks attach to a dog and fill with blood in from 3 to 6 days. These engorged seed ticks are Irluish and about the size of a No. 8 shot. They drop from the dog and hide in cracks, and in from 6 to 23 days they molt their skins and become 8- legged reddish-brown nymphs. After a few days of inactivity these nymphs are ready for attachment to dogs. After such attachment, they become en- gorged in from 4 to 9 days. At this time they are oval, about the size of a No. 5 shot, and dark gray. Again they leave the host, hide away, and molt -2- their skins in from 12 to 29 days. They are now adult males and females (figs. 1 and 2), reddish brown and very active when disturbed. In this stage they attach to various parts of the dog, and the females become engorged in from 6 to 50 days, then drop off as explained previously. In each of the unengorged stages this tick is capable of living for long periods without food. For instance, some adults have lived in confinement for over 200 days. Control . — In combating this tick it is necessary to give attention not only to the treatment of the infested animals, but also to pay especial attention to the sleeping places of the dogs, which are usually heavily infested with all stages of the ticks. Clipping long-haired dogs aids in keeping them free from ticks, but this is really not necessary. There are a number of different insecti- cides which may be used as washes or dips on the infested animals. Of these, derris wash is the most satisfactory. It is made by mixing 2 ounces of fine derris powder, 1 ounce of neutral soap, and 1 gallon of tepid water. The derris powder should contain at least 3 percent of rotenone (the main insecticidal constituent of the powder). This may be applied as a dip by putting the dog in a tub containing it, or it may be applied thoroughly with a brush. The dip is allowed to dry on, or, if necessary, the surplus liquid may be removed with a towel. The dip can be kept for at least a week. To prevent any tick from engorging and escaping from the dog, the wash should be applied at 3-day intervals. If the use of the wash is objectionable, the derris powder may be applied lightly next to the skin on all infested parts of the animal. Do not permit the powder or dip to get into the eyes. Infested dogs should be kept in one place, especially during their sleeping hours. This more or less confines the ticks to that place and makes the treatment easier. The kennels in which the infested animals sleep should be thoroughly sprayed with creosote oil without dilution. This material is the same as that used for the prevention of decay of posts and timbers. It stains and is very caustic; therefore it should not be used in houses and should not be allowed to come in contact with animals or plants. It penetrates wood and cracks and can be relied upon to destroy with a single treatment practically all the ticks in the building. If corrugated or other metal kennels or cages are being used, it is probably best not to use the creosote oil, but to spray with creosote dip. The strength should be triple that usually recommended for disinfecting purposes. The use of a gasoline torch or pear-burner in concrete or other fireproof buildings is satisfactory for the destruction of the ticks in the cracks and floors. Such a torch may be employed, if used with care, even in a wooden building. In dog and cat hospitals special attention should be given to having the cages and buildings constructed so as to reduce hiding places for ticks -3- to a minimum. Smooth concrete floors and walls are desirable, and cages made of iron give much less opportunity for the ticks to hide than wooden ones. When residences become infested it is best to keep the dogs out of doors except when they are allowed to enter the house to serve as traps for the free ticks. The baseboards, window casings, and other infested places should be sprayed frequently with one of the standard fly sprays, which are essentially kerosene extracts of pyrethrum. The ticks are quite resistant to sprays of this kind and must be wetted thoroughly if they are to be killed. In addition to the spray, the use of fresh pyrethrum or derris powder scattered behind baseboards and other hiding places is advised. If the dog is kept indoors it should be treated regularly as outlined above. The treatment of the dog and the premises must be per- sisted in for several months to eradicate the pest. Fumigation of infested houses is seldom advisable because the ticks are usually present in entryways, around porches, and in outbuildings where they cannot be reached with a fumigant. Furthermore, the tick is very resistant to fumigants. ^^^^^ \ Digitized by the Internet Archive in 2013 II http://archive.org/details/browndogtickwithOOunit_0 Figure 1. The male brown dog tick aa seen from above. About 20 times natural size. Flifure 2.— The female brown dog tick as Been from above. About 20 "^^^ri^es nalSral size. After attachment to a ^og for a fe, days the body of the female becomee greatly distended with blood. V UNIVERSITY OF FLORIDA mmwmm 3 1262 09226 9405