58 



THE AGRICCTLTURAL NEWS. 



February 17, 1912. 



expensive than *hi those countries where hibour is more 



plentiful. .1 



INSECT NOTES. 



THE NEW ZEAL.AND GRASS GRUB. 



The New Zealand grass grub {Odontria ^eal-uidifn) is of 

 great econoniic importance, both on account of the extreme 

 abundance of the insect as a pest and of the value of the 

 grass crop in New Zealand. 



The following notes and the brief abstract from the 

 article on this insect by Mr. A. H. Cockayne, Government 

 Biologist, which appeared in the Jnuriial or the Xi-p' Zfuland 

 Di'partmoit of A'jricidtdi-e, .September 15, 1911, p. 221, 

 sliould be of interest to readers of the Ayrkidtural 

 Keivs, in view of the fact that at the present time much is 

 being written in different parts of the world about the attacks 

 of root feeding inse&ts which are more or less related to the 

 one now under discussion. 



In Barbados, the root borer (Diajirepes (ilihreviatns) 

 feeds on the fibrous roots of the sugar-cane, and penetrates the 

 underground stem system of the plant. A brief account of 

 this insect, with illustrations and references, appeared in the 

 A grind tun il News, Vol. X, p. 218. 



A new pest of sugarcane has during the past year made 

 its appearance in Mauritlu.s, where a severe infestation includ- 

 ing some 4,000 acres has occurred (see Agrictdtiiral News, 

 Vol. X, p. 314). The new insect, which is not yet identified, 

 is different from the well-known root feeding grub in that 

 island, which is Ort/ctes taraiidus. 



In Samoa also (see Agricultural News, Vol. X, p. 409), 

 a pest of sugar-cane has recently made its appearance. This 

 is believed to be a new introduction, and is mentioned as 

 a rhinoceros beetle {Oryctes sp.). 



In the United State.s, Ligyrxis rugiccps is known as 

 a pest attacking the roots of Indian corn, and the May beetles 

 of the genera Lachnosterna and Cyclocephala are well-known 

 pests, which attack grasses and sugarcane, in different local- 

 ities. With the exception of Biaprepes ahhreviatus, the insects 

 mentioned are all of the same group of beetles. Diaprepes 

 is a weevil, belongifig to the Ehynchophora, while the others 

 are classed among the Lamellicornia — a large group in 

 which the grubs are largely root feeders, and the adults leaf 

 feeders. The insects mentioned are all pests of related plants, 

 such as grasses, Indian corn and sugar- cane. 



The grass grub is a native of New Zealand. There are 

 some twelve species of the genus Odontria known to occur 

 in that island, but of these only 0. zenl'tndira has become 

 a pest. 



The adult beetles occur in November and December and 

 deposit eggs in the ground, a little below the surface. The 

 eggs hatch in aliout four weeks, and the grubs feed on the 

 roots of various grasse.s, for a period of about six months, 

 during which time'they become full-grown. There is some 

 uncertainty as to whether the pupal stage is entered upon at 

 once, on the completion of the larval growth, or whether the 

 grubs remain in the soil for some time liefore pupating. 

 The adult beetles are leaf feeders, and often become a serious 

 [lest of fruit trees. 



No satisfactory means of control of this pest seems to be 

 known. The lack of labour in a country where the agricul- 

 tural practice is extensive rather than intensive renders the 

 collection by hand of adults and larvae more difficult and 



FORMALIN AS A POISON FOR THE 

 HOUSE-FLY. 



Experiments carried out by Mr. R. I. Smith, B.Sc, 

 Entomologist to the North Carolina Experiment Station, 

 have continued to demonstrate the value of formalin as 

 a poison to be used in the control of the house-fly {Miisca 

 domestica). The following notes are abstracted from a paper 

 on this subject which appeared in the Journal of Economic 

 Entomology for October 1911. 



The horse barns and dairy at the North Carolina Agri- 

 cultural and Mechanical College became infested with 

 enormous number of flies, during June 1911, and the experi- 

 ments referred to were undertaken in connexion with the 

 work of reducing the numbers of these insects. In the milk 

 room of the dairy the windows and doors were screened, and 

 a mixture consisting of 1 oz. of formalin (40 per cent, for- 

 maldehyde) and 16 oz. (1 pint) of fresh milk was exposed in 

 shallow plates. The flies at once began to feed greedily on 

 the poisoned milk, and within a few minutes commenced to 

 die. The poison was exposed to the flies at about 3 o'clock 

 in one afternoon, and at about 8 am. the next day about 

 1 pint of flies Vas swept up from the floor. This amount 

 would represent approximately .5,000 individuals. 



The trials of this mixture, and of one in which one half 

 of the milk was replaced by water, were repeated in the horse 

 liarn and the calf barn at the College and Experiment Station, 

 where enormous numbers of flies were killed. 



The use of the formalin mixtures also resulted in practi- 

 cally freeing the College mess hall of flies, in two days. 



Mr. Smiths records the successful use of this poison 

 mixture by several others. It is stated, however, that when 

 this mixture has been used in dwelling houses, it has not 

 been as successful, except in the case of unscreened kitch- 

 ens and dinin" rooms. 



Casein Manufacture in Australia.— It is re- 

 ported that a factory will be established at Lismore, in New 

 South Wales, for the manufacture of casein. While the central 

 depot, or factory proper, will be at Lismore, receiving depots 

 for skimmed milk, or, as they are known in the trade, preci- 

 pitating stations, will be established wherever a supply of 

 from 2,000 to ^t)00 gallons of skimmed milk can be obtained. 

 At these stations the casein will l>e separated from the whey, 

 and the product obtained forwarded to the head factory for 

 final treatment. There will be collecting routes from these sta- 

 tions similar to those in the present system of cream-collecting, 

 only the skimmed milk will be purchased at the farms, and the 

 farmers will have no further risk. The whey left after the 

 casein has been precipitated will be fed to pigs. Farmers 

 who now feed pigs as the only means of using uu the skimmed 

 milk, and who desire to continue pig-breeding, will be able 

 to buy back supplies of the whey from the [irecipitating 

 station, corresppjiding to the amount of skimmed milk sup- 

 plied. The prite to be paid farmers will, i' is estimated, be 

 an increase of something like 100 per cent, on the value of 

 the skimmed milk as pig feed. In other words, where the 

 skimmed milk i4- now worth, say, \d. a gallon, it will be worth 

 hd. when sold to the casein factory. These figures are not 

 given as the a</tual rates, but they serve as an approximate 

 estimate. (The Chnmber of Commerce Journal, November 

 1911, p. 347.) 



