Gordon R. Stairs

Dosage-mortality and time-mortality studies of a granulosis virus in a laboratory strain of the codling moth, Laspeyresia pomonella

Different doses of a granulosis virus were administered to first- and fifth-instar larvae of the codling moth Laspeyresia pomonella. Virus was very pathogenic for both larval instars. The LD50 values for first- and fifth-instar larvae were 5 and 49 capsules/larva, respectively. However, fifth-instar larvae were much more variable in their response to virus than first-instar larvae. Using probit methods it was calculated that 1 capsule could cause death in about 25% of both larval instars but 1578 capsules were required to cause 70% mortality of fifth-instar larvae as compared to 12 capsules for first-instar larvae. This is the first report of a decided difference in variability of response to virus by two larval instars of the same species. A bimodal response by both larval instars was observed in time-mortality studies. Apparently, about 20% of the larvae were very resistant to virus infections.

A disease of the honey bee causing behavioral changes and mortality

Abstract A disease of Apis mellifera adults was observed to cause abnormal behavior and mortality. Tests conducted on colonies isolated in observation hives and in flight cages showed that diseased bees were often attacked by other bees in the colony and, as a result of the attacking, diseased bees became black and hairless. The attacking bees themselves became infected, hence, the disease was transmitted through the colony. Occasionally diseased bees were not attacked but withdrew from the main cluster and died. Bacteria-free suspensions prepared from diseased bees were infectious when injected into healthy bees and a number of viruslike particles were found in these suspensions. The effect of the disease on the welfare of the colony was followed by the experimental introduction of diseased bees into healthy normal colonies.

Changes in growth and virulence of a nuclear polyhedrosis virus from Choristoneura fumiferana after passage in Trichoplusia ni and Galleria mellonella

Abstract An isolate of nuclear polyhedrosis virus from Choristoneura fumiferana was fed to neonate larvae of Trichopulsia ni and Galleria mellonella . It caused infection and mortality in both of these species. After passage in the alternate hosts, the isolate became increasingly virulent for these hosts. The passaged virus retained its infectivity for Choristoneura but diseased larvae did not wilt and at death they were found to contain only a few polyhedra indicating the virus had been changed.

The effects of ultraviolet irradiation on a baculovirus infecting Galleria mellonella

Abstract The nuclear-polyhedrosis virus ( Baculovirus ) of Galleria mellonella was inactivated by exposure to far ultraviolet radiation (2537 A) and to near ultraviolet radiation (3000–3800 A). Based on the dosage required for inactivation and the pattern of response, the mode of action of each type of radiation appears distinctive. The shape of the virus inactivation curve was found to depend on virus concentration, whereas the mode of action for each type of radiation was found to be constant.

The effect of presence of a queen upon outbreak of a hairless-black syndrome in the honey bee

Abstract Mortalities in 68 populations, of about 100 bees each, confined to small cages containing a piece of comb were tabulated daily and symptoms of the disease were observed until all bees had died. Various experimental treatments were administered, the most important of which was the presence or absence of a queen in each population. Queenless populations usually showed some bees chewing and nibbling upon others (a symptom of the disease) in 3–5 days, whereas queenright units usually did not show this symptom for 10 days or longer. Average length of life in queenless units was about three-fourths as long as in queenright units. Some confirmation of these results was obtained from larger populations allowed to fly in a flight cage.

Electron microscope and microfilter studies on infectious nuclear-polyhedrosis virus in Galleria mellonella larvae

Abstract Electron microscope and microfilter studies of the nuclear-polyhedrosis virus of Galleria mellonella, the greater wax moth, showed that the smallest infectious units in the cell cytoplasm and hemolymph of diseased individuals are rod-shaped virions 38 nm × 100 to 400 nm. These particles are not surrounded by membranes and are believed to be functional in spreading disease from cell to cell within the body of the host.

Susceptibility of Trichoplusia ni, Heliothis zea (Noctuidae), and Manduca sexta (Sphingidae) to a nuclear polyhedrosis virus from Galleria mellonella (Pyralidae)

Several alternate hosts were tested for their relative susceptibility to an isolate of Galleria mellonella nuclear polyhedrosis virus. Neonate Trichoplusia ni, Heliothis zea, and Manduca sexta were all susceptible to per oral administration of purified polyhedra. Of the three alternate species tested, T. ni was the most susceptible, and exhibited the most variable mortality response over the dose range tested, while M. sexta was the least susceptible. We believe this represents the first report of a lethal virus infection in a sphingid species, and useful parameters for the successful inoculation of alternate hosts are discussed.

Infectious components of granulosis virus of the codling moth, Carpocapsa pomonella☆

Abstract Infectious elements of a granulosis virus of the codling moth, Carpocapsa pomonella , were investigated using centrifugation techniques. An infectious form, smaller than the rod-shaped virus particle, was found. This component caused typical granulosis disease when fed to first-instar, host larvae. Thus, it contained all the genetic information necessary to cause the development of rod-shaped virus particles and mature granules.

The development of nuclear-polyhedrosis virus in ligatured larvae of the greater wax moth, Galleria mellonella

Nuclear-polyhedrosis virus developed more slowly in ligatured mature larvae of the greater wax moth, Galleria mellonella, than in similar unligatured larvae. The ligatured larvae were in an arrested state of development although they were kept at an optimum environmental temperature (30°C). Apparently, the rate of virus development is influenced more by the rate of host-cell metabolism than by environmental temperature.

Virus causing paralysis of adult honeybees in Ohio.

Abstract Adult paralyzed honey bees from a heavily diseased colony were examined. Preparations contained two forms of virus particles, of which about 80% were icosahedral (pentagonal and hexagonal) particles, similar in form to those described by Bailey et al. (1963) as ABPV (acute bee-paralysis virus) but differing in size. The average size of these particles was 346 A. The other 20% of the particles were generally the same in shape and size as CBPV (chronic bee-paralysis virus) with an average size of 234 × 456 A. Adult bees injected with the infectious material and held at two different temperatures died much sooner than those individuals injected with sterile water or those not injected.