PocketLab (United States)

Python library for reading and writing image data

A virus isolated from the blood of a healthy steer and designated DPP53 was shown to have rhabdovirus morphology. Although DPP53 virus was antigenically related to Tibrogargan virus by reciprocal immunofluorescence and neutralization tests, the viruses were distinguishable by neutralization tests. DPP53 virus contained RNA and was sensitive to both ether and chloroform. The geographical distribution of neutralizing antibody to DPP53 virus in Australian cattle corresponded to the distribution of Culicoides brevitarsis indicating that this virus may be arthropod-borne with this midge as a possible vector. Antibody to DPP53 virus was detected in serum from cattle, buffalo, dogs and one horse, but not in serum from deer, pigs, humans or wallabies. Highest virus titres were obtained by growth in Vero and BHK21 cell cultures, but the virus could also be grown in Aedes albopictus cell cultures. Higher virus titres were obtained when the multiplicity of infection was low. The name advanced for DPP53 virus is 'Coastal Plains' virus.

Plagiohammus spinipennis (Thorns.), a native of areas of Central and South America where rainfall exceeds 50 in. per annum, has been imported into Hawaii and Australia for the control of Lantana camara. The larvae girdle a stem of the host-plant and then tunnel extensively in the xylem tissues. In Hawaii multiple infestation of stems over 0-5 in. in thickness was found to be usual. Most attacks were within 25 in. of the ground and stems were killed or so severely weakened that they readily broke off, reducing tall plants to mutilated stumps eventually bearing small regrowth shoots. The life-cycle normally lasts one year.An annual rainfall of at least 50 in. appears to be necessary for the development of large populations, and the amount that falls before and during the oviposition period influences larval survival. It is concluded that the insect should be very useful as a biological control agent for L. camara.