Newman (1910, p. 10) speaks very highly concerning the value of kerosene in controlling the pest: "The method of trapping the fly by the use of kerosene placed in bright, shallow, new tins, or better still in white saucers, has proved the most successful artificial method yet discovered and used in this state. . . . Large numbers of the flies have been captured by this simple means, and if consistently and universally used would cause a great reduction of the pest. Large numbers of the flies so caught have been examined and found to contain eggs." Newman now adds "large numbers" to his previous statement "female flies removed from the oil showed upon examination to be fertile, being yet full of eggs."

In New South Wales, Allen (1907, p. 546) experimented with kerosene to trap the Mediterranean fruit fly and says that the fly was "caught in quantities" but he fails to mention the number of males and females captured.

Gurney (1908, p. 581) and (1910, p. 425) also of New South Wales tried the kerosene method of controlling the Mediterranean fruit fly and writes, "As many as 200 adults have been captured in a couple of tins within three days." But like Allen he does not state the per cent of males and females captured.

A few South African entomologists also experimented with kerosene to trap the Mediterranean fruit fly and although some experimenta! work was carried on yet all of these entomologists overlooked the fact that the number of female flies captured in the oil form but a small per cent of the total number of flies caught.

Dewar (1908, p. 3) captured 444 fruit flies in 122 days in two tins containing kerosene, "one placed in, and the other under, a small citrus tree," but no mention was made of the ratio of males to females.

Mally (1908, pp. 3. 5) tested the fondness of the fruit flies in captivity for kerosene and certain sweets. He liberated over 1,000 fruit flies in a cage containing two dishes of kerosene and "after six hours only 37 flies had been caught" but no mention was made of the number of males and females captured.

Lounsbury (1908, p. 6) kept a record of the number of fruit flies that he captured in kerosene and in two of the catches he stated the number of males and females removed from the trap. "On January 19 the first fruit fly, a male, was found in the oil; and in the week following three more were taken. Then from January 26 to February 6, five were taken. After that the catch became much better. Between February 6 and 11, 10 females and 12 males became victims. For the next 10 days the total was 19, and for the next week, 15; and from then, February 28 to March 17, the total was 30.”

Ehrhorn (1912, p. 4), superintendent of entomology in the Hawaiian Islands, writes as follows concerning the number of male and female Mediterranean fruit flies captured in kerosene traps. "Among the various experiments tried against the fruit fly, the use of kerosene traps has shown that enormous quantities of male flies can be trapped by this method, but so far very few females have been captured." The results of our investigations with the use of kerosene to trap the Mediterranean fruit fly were read in Honolulu before the Agricultural Seminar on November 9, 1911, and January 11, 1912, at which this entomologist was present and yet Ehrhorn has published this result as well as other observations which we announced at these scientific meetings without due credit being given to our labors.

BIBLIOGRAPHY

ALLEN, W. J., 1907. Orchard Notes. Agric. Gaz. N. S. W., XVIII, pp. 546–551. COMPERE, G., 1907. Kerosene Remedy and the Fruit Fly (Ceratitis capitata). Jour. Agric. Western Australia, XV, pp. 244-5.

DEWAR, W. R., 1908. The Fruit Fly. Paraffin Remedy versus Poisoned Bait. Rept. Agric. Jour. Cape of Good Hope, May, No. 18, pp. 1-8.

EHRHORN, E. M., 1912. The Mediterranean Fruit Fly (Ceratitis capitata Wied.) Bd. Agric. Forestry, Cir. No. 3, pp. 1-7.

FULLER, C., 1907. Paraffin and the Fruit Fly. Agric. Jour. Natal., X, pp. 645–6. GURNEY, W. B., 1908. Gosford-Narara Fruit Fly and Codling Moth Control Experiment. Agric. Gaz. N. S. W., XIX, pp. 581-4.

1910. Fruit Flies and other Insects Attacking Cultivated and Wild Fruits in New South Wales. Ibid., XXI, pp. 423-433.

HOOPER, T., 1907. Fruit Fly. Instructions to Fruit Growers. Jour. Agric. Western Australia, XV, pp. 696-7.

1909. Trapping Fruit Flies. Ibid., XVIII, p. 271.

HOWLETT, F. M., 1912. The Effect of Oil of Citronella on two Species of Dacus.
Trans. Ent. Soc. London, pp. 412-8.

JEFFERSON, J. S., 1907. Fruit Fly. Jour. Agric. Western Australia, XV, pp. 160-6.
LOUNSBURY, C. P., 1908. Supplementary Note by Government Entomologist.
Rept. Agric. Jour. Cape of Good Hope, May, No. 18, pp. 6-8.
MALLY, C. W., 1908. The Fruit Fly.
pp. 1-5.

Paraffin Remedy versus Poisoned Bait. Ibid.,

NEWMAN, L. J., 1910. Fruit Fly. Dept. Agric. Indus. Western Australia, Bull. No. 38, pp. 1-11.

QUINN, G., 1907. The Fruit-maggot-fly Pests. Dept. Agric. Intell. South Australia, Bull. No. 25, pp. 1-12.

WEINLAND, H. A., 1912. The Mediterranean Fruit Fly in Hawaii. Cal. State Comm. Hort. Mon. Bull. No. 7, I, pp. 261–270.

THE EFFECT OF TIDES AND RAINFALL ON THE BREEDING OF SALT MARSH MOSQUITOES

By P. L. BUTTRICK, New Haven, Conn.

Early in the Spring of 1912 the Civic Federation of New Haven (Connecticut) raised funds for a campaign to control the mosquito nuisance which every summer for many years has given the city a distinction second only to certain places in New Jersey.

The chief species to be controlled was the banded salt marsh mosquito (Culex sollicitans Walk.). It was hoped to secure funds enough to ditch all the salt marshes within five miles of the center of the city, but as this was not done it was thought best to use some of the funds to oil areas which could not be drained, thus temporarily keeping down the numbers of the pest.

Early in June the writer was placed in charge of this work, as well as part of the ditching operations. The following is an amplification of part of his report to the New Haven Anti-Mosquito Committee, Inc., of the Civic Federation of New Haven, and is published with its consent. Acknowledgment is due the officials of the Engineer Corps, U. S. Army, stationed at New Haven, for permission to use government tide gage readings, and for many valuable suggestions.

The life history of the salt marsh mosquito was worked out some ten years ago by the late John B. Smith and his assistants. The eggs are laid singly on the salt marsh mud and lie dormant until covered by water, either tide or rain. They then hatch in a few hours; and in from six to fifteen days, according to the temperature, the pupae transform to adults. After hovering about the marsh grass for a day or two they migrate or are blown distances and invade summer resorts, country sides, and cities, making life miserable for the inhabitants. A few return to the marsh or remain in its vicinity and start the next generation.

The marshes where the salt marsh mosquitoes breed are usually flooded at certain periods when the tides rise above the general level, as usually occurs under the new moon. These are called the perigce tides. Consequently, shortly after this period, a brood of mosquitoes is liable to emerge. At other periods when the tides are high or when the marshes are flooded by rain other broods may be produced.

In an oiling campaign a knowledge of the time of the perigee tides is of the highest importance as it gives an opportunity for making preparations for controlling the brood following it. To determine this time, if possible, more accurately than can be done by calendar, a copy of the tide tables of the United States Coast and Geodetic Sur

vey was obtained.

These are published annually and predict for the year the time and heights of the tides for certain important harbors on the coasts of the United States. By simple calculations, the predictions can be extended to almost any point on the coast.

These predictions are obtained by methods of very great complexity which it is not necessary to discuss here. They are highly accurate as to time and reasonably so as to height. Their inaccuracies are due largely to meterological causes which can be predicted only approximately and for a short period in advance. The predictions themselves are based on variation of the astronomical phenomena which cause the tides.

The height of the maximum high tide at a given station for each day of the mosquito season may be plotted on cross section paper and a curve drawn connecting these points. If desired, a second curve may be plotted showing the height of the minimum high tides, for the two tides which occur daily seldom rise to the same height. If both high tides are plotted it will be seen that more regular curves are obtained by crossing the curves on dates when both tides rise to the same height which occurs about every fortnight. On the accompanying chart (figure 6) compare the 1912 and '13 prediction curves, where both tides are plotted with those for 1910 and '11, where only the maximums are given.

Such curves show a variation of nearly half the height of the highest tides, and also that there are more or less definite periods of extreme high tides followed by periods of low high tides. By plotting the phases of the moon on the same sheet, it may be seen that the periods of extreme high tides fall under the new and the full moon. These are called spring tides. The periods of low high tides fall under the moon's first and third quarter and are called neap tides. The period of highest high water is generally at the new moon and is called the perigee tide.

It should be understood that a curve of this kind does not show the daily fluctuation of the water level, only the predicted daily maximums. Curves showing the predicted daily rise and fall may easily be constructed but are of less value, since the discrepancy between the predicted and the actual height for a given day may be quite great, but when distributed over several days is reduced.

After plotting the high tide curves the next point is to determine at what height of tide a given marsh is flooded. There are three ways of obtaining this. First; by setting a tide gage at some convenient point on a stream or in the marsh. The records of this gage will establish a flood line below which the general surface of the marsh is not cov