S30 



THE AGRICJLTURAL NEWS. 



OCTOBEE 14, 1911. 



INSECT NOTES. 



THE HOUSE-FLY AND MAN. 



In previnu.s numbers of the A'/ricultiiral A'ni's (see 

 Vols. VII, p. 26: VIII, p. 238; IX,' p. 298) articles have 

 appeared dealing with the housefly (Mtisca domeitica, Linn.). 

 A Farmer's Bulletin (No. 459) issued recently by the United 

 States Department of Agriculture entitled House Flies, by 

 L. O. Howard, Chief of the Bureau of Entomology, gives an 

 excellent account of the hou.se-tiy, and describes several other 

 similar insects which are often found in houses. 



The house-fly breeds in manure and decaying organic 

 matter, where the eggs are deposited and the larval and pupal 

 stages are passed. The adult in.= ect often flies directly from 

 its filthy breeding place into houses, where it settles on or in 

 food materials. Other flics which occur in houses have similar 

 habits, breeding in the same or similar situations, and are 

 also carriers of filth. 



The greatest importance attaches to the house-fly on 

 account of its ability to carry disease germs. The name 

 typhoid fly has been given to this insect, and is now common- 

 ly in use in the United States, in order that the people 

 generally may constantly be reminded of the dangerous char- 

 acter of this familiar insect. 



According to Dr. Howard, flies are not only a factor in 

 the distribution of typhoid and other intestinal diseases, such 

 as Asiatic cholera, dysentery and infantile diarrhoea, but 

 they are believed to aid in the dissemination of tuberculosis, 

 anthrax, yaws, opiithalmia, small pox, tropical sore and 

 parasitic worms. In the case of certain of these diseases, 

 actual laboratory proof exists as to the agency of the insects, 

 and in other cases the circumstantial evidence leads almost to 

 certainty. 



In discussing remedies and preventives, Dr. Howard 

 gives the results of experiments in the control of flies. One 

 of the most satisfactory methods employed consists in enclos- 

 ing manure from the stables in a tight vault each day and 

 scattering over the surface a .'•hovclful of chloride of lime. 

 The manure is removed from the vault about once a week. 



In agricultural districts the problem of fly control is more 

 difficult, but cleanliness and the use of chloride of lime and 

 kerosene will do much to reduce the numliers. 



In applying measures for fly control to the conditions in 

 West Indian towns and villages, the greatest ])ossible degree 

 of cleanliness would bo of first importance. The satisfactory 

 disposal of all garbage in such a manner as to prevent the 

 breeding of flies is a necessity. This might lie accomplished 

 by burning, bury ing,or by treating with lime or chloride of lime. 



The greatest care is necessary in disposing of manure 

 and all exaementitious matter, especially in the case of human 

 wccrement during the occurrence of typhoid fever in any 

 locality. ( )n estates, much could probably be accomplished 

 by carefully cleaning up all garbage and rubbish and adding 

 these to the manure pile, which might be thoroughly covered 

 with mould once each week. Kerosene as a contact in.secti- 

 eide is fatal to the larvae and pupae of flies, and has a distinct 

 Talue in treating privy vaults where these are not cleaned out 

 frequently. 



On estates where flies are abundant and the treatment 

 of their breeding places is found to be difficult, dwellings, or 

 at least kitchens and dining-rooms should be made inaccessi- 

 ble to flies l)y means of screens at doors and windows, in order 

 to protect food from these pests. If everyone would remem- 

 ber that flies live, grow and reach maturity in filth, and that 

 where opportunity offers the winged adults make their way 

 directly from their filthy breeding places to food which they 

 contaminate always with uncleanness and often with disease, 

 the necessity for fly control might be more thoroughly 

 realized. This realization .should bs assisted by the knowl- 

 edge that flies also visit all sorts of loathsome sores, and 

 frequently carry the causative organism to healthy individuals. 



LOCOMOTION OF YOUNG SCALE 

 INSECTS. 



In an article bearing the heading given above, which 

 appeared in a recent number of the Journal of Economic 

 Entomohyy (Vol. IV, p. 301) Mr. H. J. Qua'yle, of the 

 Agricultural Experiment Station, fjerkeley, California, gives 

 the results of experiments on the [jowers of locomotion of 

 the young of the black scale (Saissefia oleae, Bern.), the red 

 or orange scale {Chi-i/so?iiphaius aiirantii, Mask.), and the 

 purple scale {Lejndosaplies berkii, Newm.), which represent 

 the most serious insect enemies of citrus trees in southern 

 California. 



The experiments showed that the wind is not likely to 

 dislodge the active young of scale insects and thus greatly 

 aid in their distribution, nor are these tender animals able 

 by their own powers of locomotion to travel over the surface 

 of the soil, uniler ordinary conditions, in sutflcient numbers to 

 account for .serious and rapid spread throughout an orchard. 



The means of spread of scale insects are described in 

 the following paragraphs taken from the article referred 

 to above : — 



'The distribution of .scale insects over long distances is 

 effected mainly through the interchange of nursery stock, 

 and over the same general community by birds and active 

 in.sects, chiefly, together with the agency of man in his usual 

 cultural operations, while in the spread from tree to tree 

 or to nearby trees, aside from the above factors, the power 

 of the insects to transport themselves must be taken into 

 consideration. The wind is another factor which may aid 

 certain insects in distributing themselve-s either by blowing 

 them directly or with a leaf or light twig upon whirii they 

 may be resting Such insects as winged plant ii..- and 

 the males of scale insects have frequently been ob-erved 

 to be wafted by a gentle breeze or aided in their flight 

 through its influence. Experiments with a foot bellows 

 showed that young black scales are not very readily 

 dislodged from a twig, but once dislodged might be 

 carried a short distance as they fell. Twigs having numerous 

 active young scales had to be brought to within about six 

 inches of tlie mouth of the bellows before any of the insects 

 were dislodged. It thus requires a stronger wind than usually 

 blows to have any effect on the scales on the tree, but once 

 dislodged the wind might carry them to an adjoining tree, if 

 the foliage of the different trees were in close proximity 



'The experiments recorded here represent but a few of 

 the total number made, but they will serve to show how they 

 average. In the case of the black scale, it was shown that 

 about 4 feet of ordinary orchard soil is about the limit that 

 will be traversed by the active young. Under favourable 

 conditions they might, therefore, through their own powers 



