'3 0jK Circular No t3. Second Series United State )epartmen1 of Am NTOMOLOOY. ni s wi> M I vs. MOSQUITOES ni inii a single Bpeci ,,f ii, n mo9l parte of the countrj . but as a italogueof the I >iptera records twentj one spe< ii - From North Ann ind Mi I W I rich Btates thai he has observed al :,n -p. . i. in Trinidad. Twenty Bpecies are contained in the rollection of the I . tf. National Museum. The follow im.: statement concerning the lit'-' history of these insects ie I upon :i series of observations made in this Division upon the development of two summer generations of Culex pungens, one of our coini: ind most widespread species. The writer has seen speci- - of this insect from N T ew Hampshire, Massachusetts, New York. and, District of Columbia, Illinois, Minnesota, Kentucky, Nebraska, orgia, and the Island of Jamaica, West Indies. No doubt Ibo abundant in New J< n ■laying takes place :it night. The eggs are deposited in boat- Bhaped masses on the surface of the water, the number varying from each mass. Thi may hatch in Bixteen hours. The larva; live beneath the surface of the water, coming to the top ai fre- quent intervals to breathe. The larval Btate may be completed inseven days; the pupil state may last only twenty-four hours. An entire gen- eration in summer time, then, may be completed in ten days. This th of time, however, may be almost indefinitely enlarged if the weather be cool. There are. therefore, many generations in the course -on and the insect may breed successfully in a more or less transient Burface pool of water. Mosqoitoi - hibernate in the adult condition in cellars and outhouses and under all sorts of shelter. The degree of cold makes no difference in successful hibernation : mosquitoes are abundant in the arctic regions. REMEDIES. remedies against mosquitoes in houses the best is a thoro ning of windows and the placing of nets about beds. It tin vat are troublesome in Bitting ioms during the evening, the burning of pyrethrum will bo stupefy them as to make their presence unobjectionable. Pyrethrum for this pu ould be prepared by moistening the powder sufficiently to allow of it< being roughly molded !>y hand into little cones about the Bize and Bhape of a large chocolate drop. These cor 'hen placed in a pan and thoroughly dried in an oven. When fired at the apex, Buch a cone will smoulder slowly, and send up a thin column of pungent -moke, not hurtful to man. but stupefying to mosquitoes. In actual experience two 01 three Buch cones burned during the course of an evening have given much relict from mosquitoes in Bitting room-. It does not kill the insects, however, and t best hut a palliative. 2 The mosquitoes found on the ceilings of bedrooms in the evening may be quickly and easily killed by means of a small shallow tin cup (such as the lid of a blacking box) nailed to the top of a stick and wet inside with kerosene. This cup is placed over the quiescent mosquito, which immediately drops or flies against the oily surface and is killed. But altogether the most satisfactory means of lighting mosquitoes are those which are directed to the destruction of the larva' or the abolition of breeding places. These measures are not everywhere feasible, but in many places there is absolutely no necessity for the endurance of the mosquito plague. The principal remedies of this class are three : The draining of ponds and marshes, the introduction of fish into fishless pools, and the use of kerosene on the surface of the water. The draining of breeding pools needs no discussion. Obviously the drying up of such places will prevent mosquitoes from bleeding therein, and the conditions of a successful application of this measure will, it is equally obvious, vary with each case. The introduction of fish into fishless ponds is feasible and advisable in many cases where the use of kerosene on the surface of the water would be thought undesirable. In tanks supplying drinking water, for example, fish would destroy the mosquito larva' as fast as hatched. A case is recorded in Insect Life (Vol. IV, p. 223) where carp were employed in this way with perfect success by an English gentleman living in the Riviera. At San Diego, Tex., the people use for this pur- pose a little fish, called there a perch, the species of which the writer has not been able to ascertain. Probably the common voracious little stickle-back would answer admirably as a mosquito destroyer. Probably the best, and certainly the easiest, of wholesale remedies against mosquitoes is the application of kerosene to the surface of breeding pools. The suggestion that kerosene could be used as a remedy for mosquitoes is not new and has been made more than once. Exact experiments out of doors and on a large seale were made in 1892 by the writer. These and subsequent experiments show that approximately 1 ounce of kerosene to each 15 square feet of water surface on small pools will effectually destroy all the larva* and pupae in that pool, with the additional advantage that the adult females, not deterred from attempt- ing to oviposit, are killed when they alight on the kerosene-covered water. Ordinarily the application need not be renewed for a month, though varying circumstances may require more frequent applications in certain cases. Since 1892 several demonstrations, on large and small scales, have been made of the practicability of this method. Under the writer's supervision two localities were rid of mosquitoes by the use of kerosene alone. It will, however, probably not prove feasible to treat in this way the large sea marshes along the coast where mosquitoes breed in hordes, although even here the remedy may prove to he practicable under certain conditions and in certain situations. In inland places. however, where the mosquito supply is derived from comparatively cir- cumscribed pools, the kerosene remedy will prove most useful. In some California towns, we are informed, the pit or vault behind water- closets is subject to flushing with water during the irrigation of the land near by. A period of several weeks elapses before more water is turned in, and in the meantime the water in the pit grows stagnant and becomes the breeding place of thousands of mosquitoes. Where, as in certain towns and cities, house drainage runs into such a pit and an outdoor privy with a seldom closed door is built ovei it, mosquitoes will breed .ill summer in the fluid contents of the vault and of course will infest all tlir adjacent hoi; In such teacupful of kerosene poured into each vault at ii vals of a month or less would greatlj d the annoyance from mosquitoes, it it did not altogether prevt nt it. This i where the cooperation of neighbors is mo eholder in a given neighborhood Bhould see that his vault is treated with ki ularly ami often. 'I'll'- cost i- bo trifling that it me. I imt be considered. Where, as is thi I many country homes, rain v ollci ted in barrels or purpose or another, mosquitoes may ami do breed in numbers in such vessels. If the v b< drawn in >i n tlir I xit ton i ( if the cask, it will do no harm i" pour in a little kero- sene, since tin 1 nil will not be drawn out with the water. At all events, rach receptacles should b< 1 at night to prevent egg-layi The question, What is the besl way to cover with kerosene the sur- of a pool of some Bize? is apparently Mir operation is obviously simple, but Buch a question has been asked of the Divit Simply pouring tlir oil on from any point of the shore will answer tol- erably well, since it will spread of itself, but if for any reason it is desired to coal tlic pool rapidly with kerosene, it may be advisable to spray tin- oil through a Bpraying nozzle, either from the bank or from a boat. The method of application will vary with each case, but in the class of pools which can he most advantageously treated, namely, those "t -iii.. II size, the oil can he well spread by throwing it on to windward with a wide sweep of the arm. II.-FLEAS. Judging from the specimen- "i fleas si ut to the Division of late years, with complaints of bouses infested by them, the human Ilea {Pulex irritans) \> not the species most likely to occur in U r r-at numbers in dwelling house.-, hut rather the common cos politan flea of th< and cat {Pulex serraticeps). A house may become infested with this species, even though no domestic animals he kept, for a visitor at a house where such pets are maintained may he the means of carrying home with him one or two female fleas which will