1941: Entomology

Drs. J. B. Reeside, Jr., and C. E. Dobbin, of the United States Geological Survey have found the comb of a wasp nest in Southwestern Utah. This comb, dating from the last Cretaceous, or about 80,000,000 years ago, gives more evidence as to the early presence of wasps into the world.

More positive evidence that flies will harbor or carry the virus of poliomyelitis for several days, has accumulated during the past year through the experimental work of a group of investigators from the Schools of Medicine at Yale University and Louisiana State University.

Drs. H. S. Telford and C. Wester of the North Dakota Agricultural Experiment Station have reported finding two species of malaria-carrying mosquitoes in North Dakota. While this is the first report of these species in the state, the investigators assert that the occurrence is not surprising since these species have been known to occur in Manitoba and the states surrounding North Dakota.

Dr. H. Kalimus of University College, London, has carried out a series of experiments on the social behavior of bees. His experiments show that bees not only defend their home hives but also viciously attack strange bees in the collection of food.

Drs. J. C. Brown and J. C. Cross of Texas College of Arts and Industries have carried out a series of experiments and tests which tends to show that 'blue bugs' or fowl ticks, Argus persicus, are at least one of the probable agents for the transmission of fowl paralysis.

A species of mosquito, Deinocerites spanius, reportedly only occurring in Panama, has made its appearance on the coast near Brownsville, Texas. This species, as far as is known, is harmless to man. However, this insect probably migrated to this new environment by plane. This serves as another example of how insects, heretofore foreign to the United States, may be transported.

Preliminary reports of the use of a new chemical poison-spray, phenothiazine, show that it is lethal to the codling moth worm but harmless to the bee. However the United States Department of Agriculture is carrying on more extensive tests before its general use in apple orchards is to be recommended.

Heretofore a type of red scale insects resistant to cyanide gas has baffled scientistics who have attempted to control this citrus pest. Recently Drs. R. Craig and N. W. Hardman of the University of California have shown that the spiracles or air tubes of these insects can be kept closed for 30 minutes which makes the cyanide gas useless for the control of this species. Nevertheless, these investigators are hopeful of finding a substance which may be used in combination with cyanide gas and which will in turn aid in the eradication of this pest. Another group of investigators from the University of California Citrus Experiment Station are attempting other control methods against the red scale insect. They have imported an insect from South China which acts as a red scale predator. However, orchard tests, over a period of years, will be necessary to check the apparent successful laboratory tests.

Dr. G. F. MacLeod of the University of California College of Agriculture reported the results of some laboratory experiments on cockroaches. He has shown that infra-red rays were lethal to adult cockroaches. However, no practical method for large scale eradication has been suggested. These infra-red rays were also tried on numerous plant pests but the plants were injured as well as the insects in this latter experiment.

Drs. W. H. Tisdale and A. L. Flenner of the Du Pont pest control laboratory at Wilmington, Delaware, have described a chemical compound derived from dithiocarbamic acid, which, when used as a spray disables the Japanese beetle. This chemical has also been found effective against certain internal parasites in animals as well as certain fungi causing plant diseases.

Drs. W. N. Sullivan and L. D. Goodhue of the United States Department of Agriculture have shown how rotenone or pyrethrum, insect spray poisons, can be more effective by being used as a fumigant. To produce 'aerosols' from these substances they must be sprayed over heated appliances. The advantages offered by these substances as fumigants are that they are harmless to animal life.

A. M. Chickering of Albion College reported having separated out 21 new species of spiders from his collections of 1934, 1936 and 1939 from several localities in Panama.

Dr. I. W. Pfeiffer of Yale University has reported that castration of females of the grasshopper Melanoplus differentialis resulted in a progressive depletion in fat values well below the normal level. Furthermore, her experiments also show that when the corpora allata of these castrated insects is also removed the effects of castration are eliminated and the yielded fat and water values return to a high level.

The mechanism by which the female larvae of the honeybee are differentiated into queens and workers is assumed to be determined by food and care received during the larval period, because it is quite generally accepted that such ecological factors as temperature and relative humidity are the same during the development of both castes. In order to gain a better understanding of caste determination a particular character has been selected by Drs. G. H. Mickey and R. M. Melampy of Louisiana University. They selected the fat body of the honeybee larva and made extensive cytological studies of the cells in this structure. In general, they found that the changes which the cells undergo during larval life are the same for both the queen and worker bees. However, the changes seemed to occur earlier in the larval life of the bees which were destined to become queens. See also BIOLOGY; CHEMISTRY; ZOOLOGY.