Showing papers in "Journal of Economic Entomology in 1925"
TL;DR: In order to make experimental studies comparable and statistically meaningful, the article recommends the following formula: per cent control = 100(X - Y)/X, which eliminates errors due to deaths in the control sample which were not due to the insecticide.
Abstract: There are several statistical methods used in biology (entomology) for computing the effectiveness of an insecticide, based on relating the number of dead insects in the treated plat to the number of live ones in the untreated plat. In order to make experimental studies comparable and statistically meaningful, the article recommends the following formula: per cent control = 100(X - Y)/X, where X = % living in the untreated check sample and Y = % living in the treated sample. Calculation using this method eliminates errors due to deaths in the control sample which were not due to the insecticide. An example based on treatments of San Jose scale includes computation of probable errors for X and Y, and the significance of the difference between the two counts. Common biometric convention holds that when the difference between the results of two experiments is greater than three times its probable error, the results are significant and due to the treatment applied.
11,700 citations
TL;DR: Observations made on larvae and pupae of the honeybee during the summer of 1923 at the Bee Culture Laboratory, Bureau of Entomology, U. S. Department of Agriculture are given.
Abstract: This paper gives observations made on larvae and pupae of the honeybee during the summer of 1923 at the Bee Culture Laboratory, Bureau of Entomology, U. S. Department of Agriculture. The moults for workers, queens and drones are given with detailed measurements for the different moults and description of color of the changing forms.
65 citations
TL;DR: Three new sulfur insecticides were invented during the progress of this investigation and field tests indicate that this preparation compares favorably with other colloidal sulfurs in the control of insects and apple scab.
Abstract: The toxicity of sulfur and some of its compounds was tested under laboratory and field conditions. Atmospheres containing the volatile products of lime-sulfur were found to produce lethal effects on San Jose scale ( Aspidiotus perniciosus ), especially on the young. Tests on the covers of this species indicate that they are very slightly, if at all, soluble in lime-sulfur and the common wax solvents such as benzene, xylene and turpentine.
Three new sulfur insecticides were invented during the progress of this investigation. (1) Carbon disulfide-sulfur emulsion was made by emulsifying soap and water with carbon disulfide containing dissolved sulfur. Promising results were obtained with this preparation in the control of pear psylla ( Psylla pyri ) and as a dormant spray for San Jose scale. (2) Sulfur-naphthalene dust was preparcd by dissolving flowers of sulfur in melted naphthalene, then rapidly chilling the solution and grinding the solid thus formed into a dust by means of a ball mill. As a greenhouse insecticide this dust has proved effective against red spider ( Tetranychus sp.) and aphids. (3) A colloidal sulfur was prepared by passing sulfur fumes into a dispersion medium, such as soap and water or glue and water. This method of manufacture has an advantage in that it obviates the necessity of changing the sulfur to some other form and recovering it again by chemical means. Field tests indicate that this preparation compares favorably with other colloidal sulfurs in the control of insects and apple scab.
54 citations
TL;DR: The nectar-carrier, upon her return from the field, delivers her load to one or more house-bees who put the nectar through a process which apparently reduces its water content and probably permits of the addition of enzymes such as invertase.
Abstract: This paper deals principally with the activities of bees engaged in storing and ripening honey. The nectar-carrier, upon her return from the field, delivers her load to one or more house-bees. These house-bees then put the nectar through a process which apparently reduces its water content and probably permits of the addition of enzymes such as invertase. The process is described in detail. The partly ripened nectar is then deposited in the cells where further ripening takes place.
47 citations
TL;DR: There is an apparent correlation between deficiency of rainfall and the abundance of this insect in destructive numbers and heavy precipitation while the young broods are developing under the bark produces a very heavy and effective mortality.
Abstract: The periodicity of bark-beetle epidemics is one of the most interesting phenomena connected with their occurrence. The successful application of control and preventive measures is, to a considerable extent, dependent on the entomologist's ability to foresee an increase or a decline in the existing status of the infestation. Epidemics of the southern pine beetle, which is the chief consideration in this paper, are characterized by 1 to 3 years of intense activity. During the longer intervening periods the insects are extremely rare. Precipitation records for a number of localities throughout the Southeast have been tabulated and compared with the occurrence of epidemics of this insect. There is an apparent correlation between deficiency of rainfall and the abundance of this insect in destructive numbers. Heavy precipitation while the young broods are developing under the bark produces a very heavy and effective mortality.
42 citations
TL;DR: An investigation of the aliphatic fatty acids has shown that certain members of the series possess promising insecticidal properties as contact sprays.
Abstract: An investigation of the aliphatic fatty acids has shown that certain members of the series possess promising insecticidal properties as contact sprays. The studies have indicated that the toxicity of soaps when used as contact sprays is due to the release of the acid components through hydrolytic dissociation.
25 citations
TL;DR: Exposing high producing cows to an exceedingly heavy infestation of house flies did not result in lowered production and the causes for losses in production that resulted from spraying were attempted.
Abstract: 1. This paper presents data gathered to check results secured during the summer of 1925 and to attempt to ascertain the causes for losses in production that resulted from spraying.
2. Exposing high producing cows to an exceedingly heavy infestation of house flies did not result in lowered production.
3. In the absence of flies, sponging with water had no effect on production, spraying, with water caused a loss of 5.4 per cent, with pine tar-creosote a loss of 6.9 per cent, and with oil a 9.7 per cent loss.
4. During the last two weeks of spraying the loss in production was 12.5 per cent for the pine tar-creosote and 22.8 per cent for the oil sprayed group.
5. The body temperature was consistently higher, sometimes as much as 3 degrees F., for the oil sprayed group than for the controls. The respiration rate of the former averaged 40 per cent higher than that of the latter.
22 citations
TL;DR: The Hessian fly (Phytophaga destructor Say) problem in relation to the wheat industry of Kansas is considered and calls for cooperation with other sciences, especially with agronomy.
Abstract: This paper is a consideration of the Hessian fly (Phytophaga destructor Say) problem in relation to the wheat industry of Kansas. Emphasis is placed on the fact that the Hessian fly is only one factor in the production of wheat. The study of this insect and its control is influenced by many factors, such as wheat acreage, agricultural practices, varieties of wheat, climatic conditions, etc. The problem extends beyond the realm of entomology and calls for cooperation with other sciences, and especially with agronomy.
18 citations
TL;DR: Tribolium infestation affects the elasticity and the viscosity of flour and turns flour a pinkish tinge which becomes brown upon oxidation.
Abstract: Tribolium infestation affects the elasticity and the viscosity of flour. Heavy infestation turns flour a pinkish tinge which becomes brown upon oxidation. Adults give off a characteristic secretion soluble in water. This secretion may be the cause of the marked effect which Tribolium has on the physical properties of flour colloids.
17 citations
TL;DR: This paper is an account of an outbreak of the cutworm, Euxoa Auxiliaris Grote, on alfalfa at Vernal, Utah, in 1916, which seemed, but was not conclusively proven, to be controlled by parasites.
Abstract: This paper is an account of an outbreak of the cutworm, Euxoa Auxiliaris Grote, on alfalfa at Vernal, Utah, in 1916, which seemed, but was not conclusively proven, to be controlled by parasites, of which about a dozen species were reared as follows: Berecyntus bakeri Howard, A panteles laeviceps Ashmead, Meteorus vulgaris Cresson, Amblyteles nuncius Cresson, Habrobracon erucarum Cushman, Paranomalon sp., Ernestia sp., Anthrax alternata Say, Anthrax willistonii Coquillet, Aphiochaeta . sp., and Phorichaeta cinerosa Coquillet. It contains some data on the life history, habits and occurrence of both the host and its principal parasites as observed in the field and while rearing them in an improvised insectary.
16 citations
TL;DR: A brief description is presented of the organization of the work and a brief review of some of the more interesting entomological features which have come under his observation.
Abstract: During the past few years the Mexican states of Sonora, Sinaloa and Nayarit, comprising the territory popularly known as the West Coast of Mexico have gradually assumed an intimate commercial relation to the western part of the United States. This has lead to the development of certain entomological work on a commercial foundation along lines adapted to the requirements of the situation. The writer has been engaged to a large extent in this line of work in the region mentioned during the past four years and in order to create a better understanding of the relation of such work to the pest protection problems of the North American continent, a brief description is presented of the organization of the work and a brief review of some of the more interesting entomological features which have come under his observation.
TL;DR: An application of recently acquired knowledge respecting air currents and the behavior of drifting balloons, suggests that such insects as the cotton moth, Alabama argillacea the com ear worm, Chloridea, obsoleta and a number of other southern forms really drift on the somewhat prevailing southerly or southwesterly winds.
Abstract: An application of recently acquired knowledge respecting air currents and the behavior of drifting balloons, suggests that such insects as the cotton moth, Alabama argillacea the com ear worm, Chloridea, obsoleta and a number of other southern forms really drift on the somewhat prevailing southerly or southwesterly winds, especially as convectional air currents over heated areas would very likely carry them 1000 feet or more above the earth. Mosquitoes have been observed 3000 feet above the surface. The monarch butterfly, Anosia plexippus , has spread widely in the Pacific ocean within historic times, presumably taking advantage of favorable winds both in these wanderings and its seasonal migrations. Lengthy flights of butterflies in Europe are probably explainable in the same way. The drifting and distribution of ballooning spiders is obviously due to winds and closely parallels what has been observed among insects.
TL;DR: Observations extending over ten years arc summarized and indicate that loss in growth is roughly proportional to the degree of defoliation.
Abstract: Aside from killing of trees by defoliation there is a loss in growth of those that survive. This has been measured accurately for many New England species defoliated by the gipsy moth Porthetria dispar. Observations extending over ten years arc summarized and indicate that loss in growth is roughly proportional to the degree of defoliation. In the period nearly one-half of the oaks died and the survivors lost on the average more than one-third of their foliage and growth annually.
TL;DR: This is a preliminary report on the natural enemies of Aphis spiraecola in Florida, where the citrus area of the state was injured by the aphid to the extent of about four million dollars during 1924.
Abstract: This is a preliminary report on the natural enemies of Aphis spiraecola in Florida. The citrus area of the state was injured by the aphid to the extent of about four million dollars during 1924. No true parasites were observed by the writer, but several predaceous insects are of some value in checking the aphid. In colonies on the native host plant, Spiraea spp. only two small predators were noted, a coccincllid beetle and an agromyzid fly.
TL;DR: The honey bee is a large factor in the pollination of pears and apples and is not of as great benefit in thepollination of cranberries, in New Jersey.
Abstract: The honey bee is a large factor in the pollination of pears and apples and is not of as great benefit in the pollination of cranberries, in New Jersey. These conditions are chiefly a result of weather conditions as related to the habits of honey bees and the like history of other pollinating insects.
TL;DR: The pea aphid predators are many and varied and studies this past year at Columbus, Wis., gave some idea of the abundance of certain groups and the relative importance of others.
Abstract: The pea aphid predators are many and varied. Studies this past year at Columbus, Wis., gave some idea of the abundance of certain groups and the relative importance of others. Numerous species not heretofore mentioned are included in the list.
TL;DR: More comprehensive basic ecological studies of the many species of wireworm should be made, with much more time and care given to them than in the past, to show some satisfactory answer to the oft repeated question, “How can the authors get rid of wireworms?”
Abstract: This paper purposes to treat in a general way the damage caused by the three species of wireworms of principal economic importance in Washington, Oregon, and Idaho, namely, the inflated wireworm, Ludilts inflatus Say, the dry-land wireworm, Ludius noxius Hyslop, and the wet-land wireworm, Pheletes occidentalis Candeze. The paper brings out interesting ecological data which show each of these species inhabits a separate region under distinct environmental conditions, as regards rainfall and moisture content of the soil. A general life history is given for the dry-land wireworm, showing the total life cycle of this species to be four Dr more years. A brief summary is given of the damage caused by the wet-land wireworm under irrigated farming conditions together with some interesting facts about the habits of this species during recent years. The final purpose of the paper is to show that more comprehensive basic ecological studies of the many species of wireworms should be made, with much more time and care given to them than in the past. With a more thorough knowledge of the many ecological factors involved in the increase of wireworm infestations and damage, there should be found some satisfactory answer to the oft repeated question, “How can we get rid of wireworms?”
TL;DR: This paper discusses the various ways in which the Hesssian fly damages the wheat plants and reduces yield; a series of experiments is given in tabular form, showing the loss of weight per head for each additional fly larva in the culm.
Abstract: This paper discusses the various ways in which the Hesssian fly ( Phytophaga destructor Say) damages the wheat plants and reduces yield; a series of experiments is given in tabular form, showing the loss of weight per head for each additional fly larva in the culm, and a comparison is made between the weight of yield of fly free wheat and that of fly infested wheat in which all factors affecting yield other than the Hessian fly are eliminated.
TL;DR: The development of increased immunity to hydrocyanic acid gas by the red scale and black scale in certain districts of Califomia, which have in the past relied upon fumigation for control, has become so pronounced that a single treatment even at a greatly increased dosage no longer can be depended upon to keep these pests in control.
Abstract: The development of increased immunity to hydrocyanic acid gas by the red scale and black scale in certain districts of Califomia, which have in the past relied upon fumigation for control, has become sO pronounced that a single treatment even at a greatly increased dosage no longer can be depended upon to keep these pests in control. Double fumigation is often unsatisfactory and very expensive. A situation has arisen, the solution of which demands the introduction of new methods and materials. A wave of spraying, in some cases combined with fumigation, has been sweeping these districts. At present a very unsatisfactory condition exists.
TL;DR: The persistence of the insect under these varying conditions leads to the conclusion that those climatic elements consisting of temperature and humidity are not important factors in limiting the distribution of the Mexican bean beetle.
Abstract: The Mexican bean beetle, Epilachna corrnpta Muls., is recognized as a pest of beans in three separate areas in the Northern Hemisphere. These three areas differ widely as regards temperature and moisture, one being typically arid, one humid, and the third an intermediate form with dry winters and heavy precipitation during the summer. The persistence of the insect under these varying conditions leads to the conclusion that those climatic elements consisting of temperature and humidity are not important factors in limiting the distribution of the Mexican bean beetle.
TL;DR: The results obtained by the treatment of 350 dormitory rooms have proved so much better in respect to the saving of labor, safety and effectiveness than the method of fumigation with hydrocyanic acid gas that the latter method has been abandoned in favor of superheating for control of this pest.
Abstract: During the summer of 1924 experiments were conducted in the dormitories of the Agricultural and Mechanical College of Mississippi for the control of bedbugs, Cimex lectularius Linn., by heat. Superheating of the infested rooms was secured by closing the rooms and turning on the steam heat during hot summer weather. At temperatures of 120 degrees Fahrenheit and above, absolute control was secured by treatment of several hours duration. A very high percentage mortality was secured by exposures to temperatures averaging 110 degrees Fahrenheit when maintained for two days or more. The results obtained by the treatment of 350 dormitory rooms have proved so much better in respect to the saving of labor, safety and effectiveness than the method of fumigation with hydrocyanic acid gas that the latter method has been abandoned in favor of superheating for control of this pest.
TL;DR: Two generations of the striped cucumber beetle, Diabrotica Vittata Fabr.
Abstract: Two generations of the striped cucumber beetle, Diabrotica Vittata Fabr were found in Iowa The first equired 37 days and the second 51 for development Females of the first averaged 225 eggs and the second 337 The over-wintering stage in this state has not been discovered and any extensive recommendations for biological methods of control must await this knowledge
TL;DR: Sodium fluosilicate with nine parts of hydrated lime, by volume, gave good control in field trials against the Mexican bean beetle and cage tests against the cotton boll weevil.
Abstract: Sodium fluosilicate with nine parts of hydrated lime, by volume, gave good control in field trials against the Mexican bean beetle. Sodium fluosilicate undiluted was effective in cage tests against the cotton boll weevil. .01 per cent of mustard gas (dichlorethysulfide) with a little ether adsorbed on charcoal was used successfully against the Mexican bean beetle under cages.
TL;DR: Three species of Mirids have been observed feeding on the rose leaf-hopper, Typhlocyba rosae, and arc added to the list of its natural enemies.
Abstract: Three species of Mirids have been observed feeding on the rose leaf-hopper, Typhlocyba rosae, and arc added to the list of its natural enemies. Notes are given as to abundance feeding habits and probable importance. Descriptive notes and drawings are also included.
TL;DR: Recommendations for the spraying of alfalfa to control the alFalfa weevil, Phytonomus murinus Fabr.
Abstract: Recommendations for the spraying of alfalfa to control the alfalfa weevil, Phytonomus murinus Fabr., have been guided largely by Dr. H. C. Gardiner's work on the arsenical poisoning of domestic animals, which was recorded in the transcript of the Riverside Dairy Case in the United States District Court of Utah, but which has not heretofore been readily accessible to entomologists and the public, to both of whom it is of the highest importance. Dr. Gardiner, in an exhaustive series of feeding experiments, clinical observations and autopsies, determined the physiological effect of various doses of arsenic, continued for various periods of time, upon farm animals. The dangerous dose was shown to be far greater than the amount which is contained in a feed of sprayed hay.
TL;DR: In this paper, the life-history of the eulophid parasite Tetrastichus incertus (Ratz) is described and a brief account of the previous history of the insect is included together with its known distribution and attention is directed to its probable usefulness as a parasite of the alfalfa weevil in the United States, providing establishment should prove successful.
Abstract: The following article relates features in the life-history of the eulophid parasite Tetrastichus incertus (Ratz) as disclosed by the study of alfalfa weevil material from various parts of Europe. A brief account of the previous history of the insect is included together with its known distribution and attention is directed to its probable usefulness as a parasite of the alfalfa weevil in the United States, providing establishment should prove successful.
TL;DR: The writer went to Spain to study conditions surrounding the infestation at its source and Organization of a clean-up campaign and the results obtained are outlined.
Abstract: In the fall of 1923 grapes arriving from Almeria, Spain, in New York and Boston were found to be lightly infested with the Mediterranean fruit-fly, Ceratitis Capitata Wied. Further entry was prohibited by the U. S. Federal Horticultural Board until satisfactory evidence could be presented that the grapes were no longer attacked in Spain by this fruit-fly. The writer went to Spain to study conditions surrounding the infestation at its source. The topography of the grape growing sections in the Province of Almeria, methods of culture, host-plants of the fruit-fly and amount of infestation in Almeria are described. Organization of a clean-up campaign and the results obtained are outlined. The grape embargo is closely connected with Spanish-American trade treaty relations; its probable effect on the renewal of the treaty in 1925 is discussed.
TL;DR: Correlations were made during the spring honey flows of 1922 and 1923 at Somerset, Maryland, between changes in weight of a colony of bees and daily variation in temperature, relative humidity, hours of sunshine and solar radiation by use of the formula for multiple correlation.
Abstract: Correlations were made during the spring honey flows of 1922 and 1923 at Somerset, Maryland, between changes in weight of a colony of bees and daily variation in temperature, relative humidity, hours of sunshine and solar radiation. By use of the formula for multiple correlation, exact response to changes in weight of the colony to changes in each of these weather factors was calculated. A variation in colony weight depends upon two factors acting jointly, namely the nectar secretion activity on the plants and the behavior of bees engaged in gathering nectar and pollen
From the above mentioned calculations the exact weight was given to each of the weather factors considered. A variation from the average temperature was thus noted to have either a positive or a negative effect upon the weight of the colony which in turn could be expressed in terms of grams depending upon the number of degrees the temperature varied from the average. For example, when the daily temperature was four degrees above the average, there resulted from this an increase in colony weight of so many grams due to this one factor alone. Although the other weather factors were constantly affecting the weight of the colony, at the same time the results attributed to temperature, for instance, represent that factor alone since corrections were made in each case for the effect of other factors. A quantitative as well as a qualitative analysis is given for all the weather factors enumerated above.