Properties of An Iridescent Virus From the Beetle, Serioesthis Pruinosa

Abstract

The recently described iridescent virus from Serice8this (SIV) is closely related to Tipula iridescent virus (TIV). TIV and SIV are morphologically similar and have similar sedimentation coefficients (820, w = 2200 S). SIV differs from TIV serologically and in DNA content. Large yields of purified SIV, of the order of 2 mg virus protein per pupa, maybe obtained from the wax moth, Galleria melloneUa.

The Effect of Temperature on the Development of Sericesthis Iridescent Virus

“…From the epidemiological viewpoint further work on thermal inactivation of SIV in soil is required. We already know that SIV that has been thoroughly dried over phosphorus pentoxide will withstand heating to 80°0 for 3 hr, but the virus in the presence of water, and especially in the presence of Mg2+, is more sensitive to thermal inactivation (Day and Mercer 1964).…”

“…The characteristics of the virus used have been described (Day and Mercer 1964). Viral concentration was estimated on purified preparations by measuring absorbance at 260 m"", in a Beckman DU spectrophotometer.…”

“…The observation that Sericesthis iridescent virus (SIV) developed readily in the larva of the wax moth, Galleria mellonella (L.), at 22°0 but poorly at 28°0 (Day and Mercer 1964) poses questions about the growth of the virus under field conditions. Roberts (personal communication), who discovered SIV in northern New South Wales, has found that soil temperatures frequently rise above 28°0 in pastures in which larvae infected by the virus have been located; an examination of the development of the virus under controlled laboratory conditions was therefore initiated as a preliminary to an investigation in the field.…”

The Number of Particles of Sericesthis Iridescent Virus Required to Produce Infections of Galleria Larvae

“…(4) Immunity mechanisms of the host may destroy or inhibit some otherwise infectious particles. Day and Mercer (1964) reported that the total particle/infectious particle ratio of SIV was not greater than 10: 1, but the experiments were based on tenfold dilutions, and the question has therefore been examined more closely.…”

“…Virus was prepared from infected Galleria mellonel"la larvae by centrifugation in buffer and in a sucrose density gradient (Day and Mercer 1964). SIV is unusually easy to purify, and no special precautions to overcome problems of contamination are necessary.…”