Diseased Larvae Research Articles

Susceptibility of nontarget organisms to Nosema algerae (Microsporida: Nosematidae), a parasite of mosquitoes

Laboratory studies were conducted to determine the susceptibility of nine mosquito predators to the microsoporidian pathogen of anopheline mosquitoes, Nosema algerae. The predators tested were: Anax junius (Odonata); Hydrophilus sp., Coptotomus interrogatus (Coleoptera); Notonecta undulata, Belostoma fluminea, Ranatra australis (Hemiptera); Chauliodes rastricornis (Megaloptera); Procambarus sp. (Decapoda); and Gambusia affinis (Pisces). Of these species, only Notonecta undulata was found to be susceptible to Nosema algerae after having fed upon diseased larvae. Infection rates in four tests averaged 47.9%. The following tissues were found to be infected in the adult notonectids: gut, muscle, fat body, Malpighian tubules, tracheal epithelium, testes, brain, hypodermis, and ommatidia.

Parasites and Pathogens Among Heliothis Species in the Central Mississippi Delta1

During 1972, 1973, and 1974, 4615 larvae of Heliothis zea (Boddie), H. virescens (F.), and H. subflexa (Guenee) were obtained from 9 host plants (wild and cultivated) in the Central Yazoo Mississippi Delta by whole plant examination and sweep net collection. After the larvae were identified, the number of parasitized and diseased specimens of each species was determined. The percentage of parasitized and diseased larvae was highest during early and late season. Microplitis croceipes (Cresson) and Cardiochiles nigriceps Viereck were the predominant parasites found, and Nomuraea (Spicaria) releyi (Farlow) Samson was the predominant insect pathogen.

Cuticular hydrocarbons of healthy and diseased Japanese beetle larvae

Hydrocarbons were extracted from cuticle of healthy Japanese beetle larvae and larvae infected with the milky disease organism, Bacillus popilliae. The extractable hydrocarbons were separated from other lipids by silicic acid column chromatography and analyzed by gas-liquid chromatography. The major cuticular hydrocarbons are n- tricosane , 11-methyltricosane, and 9,13-dimethyltricosane. Only minor quantitative differences were observed in the major hydrocarbons from cuticle of healthy and diseased larvae.

Replication and passage of alfalfa looper nuclear polyhedrosis virus plaque variants in cloned cell cultures and larval stages of four host species

As alfalfa looper nuclear polyhedrosis virus (NPV) was serially passed through TN-368 cell cultures, the percentage of the cell population that developed infection with the MP variant decreased, while cells infected with FP variant increased. The MP variant was more virulent to Trichoplusia ni than the FP variant. Cells from the TN-368 cell line and strains derived from single cells were infected with isolated MP plaques. The viral progeny remained homogenous after one or occasionally two passages in cultured TN-368 cells. However, further serial passes in TN-368 cells or one pass in cell strains resulted in loss of the homogeneity, and the FP variant was detected. Four species of Lepidopterous larvae were also infected with the MP variant. Both variants were detected in viral progeny from diseased larvae.

A granulosis virus from Sesamia nonagrioides

The effects of a granulosis virus from Sesamia nonagrioides were established in the larval, pupal, and adult stages. Different ages of larvae were compared as to their survival rates. Pupae deriving from diseased larvae had a sex ratio that deviated from the expected 1:1; in some of these pupae an incomplete pigmentation was noticed in abdominal segments. Adults deriving from inoculated larvae were less fertile, as measured by oviposition and by hatching rate. Offspring of inoculated parents had a greater incidence of the granulosis virus disease than did offspring of uninoculated parents.

The isolation of cricket paralysis virus from the emperor gum moth, Antheraea eucalypti Scott, and its infectivity towards a range of insect species.

Three virus-like particles have been isolated from diseased larvae of Antheraea eucalypti. Serological tests established that one of them was indistinguishable from cricket paralysis virus (CrPV). CrPV isolated from crickets and from Antheraea were cross-infectious, and crickets could acquire lethal doses of the virus by feeding on infected Antheraea larvae. In addition to two species of Teleogryllus, three other species of Orthoptera and nine out of ten species of Lepidoptera tested were susceptible to the virus. It is suggested that CrPV may have originated amongst the Lepidoptera and has been acquired by the field cricket by infectious passage along a food chain.

Interactions between Bollworms,1 a Braconid Parasite,2 and the Bacterium Serratia marcescens3

The pathogenic bacterium, Serratia marcescens Bizio, was isolated from dead laboratory-reared larvae of the braconid parasite, Microplitis croceipes Cresson, that had emerged from diseased Heliothis zea (Boddie) larvae. Laboratory feeding tests with S. marcescens against adult parasites resulted in 79% mortality in 7 days. When the bacterium was fed to isolated bollworm larvae, no mortality occurred, but when it was fed to larvae held in crowded conditions high mortality resulted. Healthy H. zea larvae died 24 hrs after being stung by wasps that had previously stung diseased larvae, and ovipositor transmission of the pathogen caused a peak mortality of 28% in 4 days. When comparisons were made between healthy and infected oviposition stings, it was found that parasite emergence was depressed 25.5% when the pathogen was present in host larvae.

Properties of flacherie virus of the silkworm, Bombyx mori

The flacherie virus of the silkworm, Bombyx mori, was isolated from infected larvae reared under aseptic conditions. Two types of infectious particles, tentatively designated FVS I and FVS II, were separated by density gradient centrifugation. Some properties of the separated particles were investigated. Electron micrographs showed that FVS I and FVS II were spherical particles with diameters of 27 ± 2 nm and 22 ± 2 nm, respectively. The sedimentation coefficients of FVS I and FVS II were 180 S and 134 S, respectively. It was concluded from experiments of incorporation of 3H-uracil inoculated into diseased larvae at late stage of flacherie disease that the nucleic acid of FVS II was RNA. The two types of particles were present in Sakaki and Wadayama strains of flacherie virus.

Milky disease (Bacillusspp.) occurrence and experimental infection in larvae ofCostelytra zealandicaand other Scarabaeidae

Milky disease was transmitted experimentally to larvae of Costelytra zealandica (White), Costleya (= Chlorochiton) suturalis Fabr., and Odontria striata White (Melolon‐thinae) by feeding and by intra‐haemocoelic injection of spores of Bacillus popilliae and two unnamed New Zealand Bacillus strains, and also to Pericoptus truncatus Fabr. (Dynastinae) by intrahaemocoelic injection and to C. zealandica by housing the larvae in soil containing the spores. The infection rate resulting from any of these methods rarely exceeded 5 %, and was usually much less. Monthly records from a 2‐acre (approx. 0.8 ha) field plot showed an initial infection rate of up to 62% in lst‐and 2nd‐instar C. zealandica larvae. Most of these were transient, non‐lethal infections which did not develop to a visibly milky condition. Evidence from field records and from the survival of diseased larvae held in the laboratory suggested a total mortality from milky disease in this population, throughout the season, of more than 20%. Records from 21 other sites are summarised.

Untersuchungen über die Aussichten einer biologischen Bekämpfung von Scolytiden an Ulmen als Mittel zur Einschränkung des „Ulmensterbens”

AbstractStudies on the possibilities of biological control of elm bark beetles (Scolytidae) with the view of reduction of the dutch elm disease. At the request of the Michigan State University the parasite complex of the European elm bark beetles, S. scolytus and S. multistriatus, was studied in eastern Austria by the European Station, C.I.B.C., in 1969. 10 species of parasites, the Braconids Coeloides scolyticida, Dendrosoter protuberans, Ecphylus silesiacus and Spathius rubidus, and the Chalcids Cheiropachus quadrum, Cerocephala cornigera, Dinotiscus aponius, Entodon ergias, Eurytoma arctica, and Eurytoma morio were found.Between 1970 and 1972 the studies were continued on behalf of the Canadian Forestry Service, and the mortality of the summer generation of S. scolytus and S. multistriatus was studied in two localities in 1970 and 1971. The total mortality between June and September was 76,3 and 79,3% for S. scolytus, and 75,1 and 84,8% for S. multistriatus. The mortality of the eggs (between 16 and 25%) was mainly caused by physical factors, losses through predation remained below 2,5%. The mortality of the first and second instar larvae reached 48% for S. scolytus, and 64% for S. multistriatus. Between 6 and 25% of the mortality of these two instars was caused by predation, the Dolichopodid M. nitida being the most important predator. The mortality of the larval instars L3–5 accounted for 30% of the total mortality. Seven species of ectoparasites were responsible for most of this mortality. C. coeloides was the most important parasite of S. scolytus, and D. protuberans was the dominant parasite of S. multistriatus. Parasitism by the endoparasite E. ergias remained below 5% in the larvae of both species. No mortality was observed for the pupae and the teneral adults. No diseased larvae or pupae were found.

Detection and Identification ofBacillus Larvaein a Commercial Sample of Bee-Collected Pollen

SummaryOne sample of pollen (produced in British Columbia, Canada) caused American foul brood disease in a healthy honeybee colony to which it was fed. An aqueous filtrate from the pollen contained a large number of bacterial spores (>109 per g pollen). The same pollen sample showed a proteolytic activity similar to that found in dried diseased larvae; it was also less attractive to foraging bees than was disease-free pollen.

Isolation and characterization of constituents in hemolymph from healthy and diseased japanese beetle larvae

AbstractStudies are reviewed on the composition of hemolymph from Japanese beetle larvae, Popillia japonica. This research was conducted to determine the chemical environment required for sporulation of the milky disease organism, Bacillus popilliae. Amino acids, proteins, organic acids, lipids, carbohydrates, and oxygen content were determined in hemolymph from healthy and diseased larvae. Oxygen content of hemolymph was measured by microelectrodes implanted in the hemocoel of living larvae. Vegetative growth of the pathogen reduces the dissolved oxygen; however, as sporulation occurs, oxygen concentration approaches normal values. Trehalose, the major hemolymph sugar, is reduced by ca. 50% during the course of milky disease. Neutral lipids, phospholipids, and hydrocarbons decrease markedly with infection. Both branched‐chain and normal alkanes occur in hemolymph. Milky disease causes an increase in concentration of pyruvic, malic, glycolic, tartaric, and glyoxylic acids. The major hemolymph protein, a lipoglycoprotein, has a mol. wt. of ca. 500,000. Reduced concentration of this protein is accompanied by the appearance of a smaller protein. Amino acids that increase significantly as a result of infection are: Glutamic acid, aspartic acid, β‐alanine, phenylalanine, threonine, lysine, and serine. Hemolymph contains few peptides of low molecular weight.

Physical and physiological characteristics of Trogoderma glabrum infected with the schizogregarine pathogen Mattesia trogodermae

Physical and physiological characteristics of an infection of Trogoderma glabrum by Mattesia trogodermae were studied. Weights of infected larvae drop markedly between 10 and 20 days post-infection at 30° and 35°C. This loss is less abrupt and not as great when the incubation temperature is 25°C. Reduction of dry matter is gradual during the first 12 days of infection, but drops 70% from 12 to 20 days post-infection. Glycogen reserves in both infected and control insects drop 50% within 3 days after deprivation of food. Healthy insects recover and begin to reconstitute lost glycogen; however, infected larvae continue to deplete glycogen to 15% of prestarvation levels. Similarly, insect protein is reduced 40% within 7 days after starvation and noninfected insects apparently halt protein metabolism at this level. Diseased larvae continue to lose protein to 20% of prestarvation amounts. These losses are at least partially attributable to insect metabolism since infected insects defecate significantly more than control larvae. It is thought that defecation is an effective route of water loss which occurs during the first 20 days of infection. Relative humidities ranging from 0 to 84% had no obvious effects on mortality rates, indicating that water loss is effected through routes other than evaporation through the cuticle, e.g., failure of water retention systems and elimination of body water with feces.

Cations in hemolymph and alimentary tract tissues of healthy and milky diseased European chafer (Amphimallon majalis) larvae.

A study was made of certain cations present in hemolymph and alimentary tract tissues of healthy and diseased European chafer larvae and the spores of Bacillus popilliae collected from diseased hemolymph. The major ions found in the hemolymph, in order of decreasing abundance, were potassium, magnesium, sodium, and calcium. Hemolymph of diseased larvae contained relatively higher concentrations of sodium, potassium, magnesium, iron, and zinc than hemolymph of healthy larvae. Concomitantly, the concentrations of ions were lower in the mid-gut and anterior intestinal tissues of diseased larvae. Only sodium decreased slightly in the diseased tissues of the rectum and rectal sac; other ions remained unchanged or increased. Little or no manganese or copper was detected in the hemolymph or tissues. The major cations of spores of B. popilliae were sodium, calcium, and magnesium. Small amounts of potassium, manganese, copper, iron, and zinc were detected in the spores. Based on calcium and dipicolinic acid determinations of the spores, sufficient calcium was found to allow for the formation of calcium dipicolinate in the expected concentrations.

Determination of Osmolalities of Insect Hemolymph from Several Species

Osmolalities of insect hemolymph were determined using an osmometer. A 0.2-ml sample gave a reliable reading. The technique was used to determine hemolymph osmolalities for the following species of Lepidoptera: Bombyx mori (L.) 311.2 milliosmols (mOsm), Malacosoma americanum (F.) 282.9 mOsm, Galleria mellonella (L.) 416.4 mOsm, Manduca sexta (L.) 318.2 mOsm, Heliothis zea (Boddie), 318.3 mOsm, Spodoptera frugiperda (J. E. Smith) 305.6 mOsm, Trichoplusia ni (Hubner) 358.6 mOsm, Hyphantria cunea (Drury) 318.2 mOsm, and Estigmene acrea (Drury) 322.2 mOsm. The hemolymph osmolality for the coleopteran Tenebrio molitor (L.) was 563.0 mOsm. No significant difference was found between hemolymph osmolalities of healthy and diseased larvae.

Alanine aminotransferase in the three last larval instars of Barathra brassicae infected by Nosema plodiae

During three last larval instars of Barathra brassicae the alanine aminotransferase activity pattern exhibits two maxima which do not correspond with the maxima of activity of phosphatases and proteases. In the larvae infected by Nosema plodiae a different course of activity can be seen from the 5th day of infection. The activity pattern in the diseased larvae rises above that of a normal larva by 90% shortly before the last molt and reaches a maximum at the end of normal larval development. Alanine aminotransferase in the gut and in the fat body exhibits two main pH optima of activity, 8.0 and 9.5, respectively, and a low activity peak at pH 4.5. This last activity is not present in diseased animals. The temperature and pH inactivation are also described.

Hemolymph factor in armyworm larvae infected with a nuclear-polyhedrosis virus toxic to Apanteles militaris

The parasitoid, Apanteles militaris, was killed or failed to pupate when its armyworm host was infected with the hypertrophic strain of a nuclear-polyhedrosis virus. Virion-free plasma from diseased larvae killed the parasitoids when injected into uninfected larvae. The toxic factor was partially precipitated from plasma that was 50% saturated with ammonium sulfate and was completely precipitated in 50% ethanol or methanol. Parasitoids in larvae infected with the typical strain of nuclear-polyhedrosis virus seemed unaffected.

The mode of transmission of Tipula iridescent virus : I. Source of infection

A virus was isolated from a diseased tipulid larva and identified as Tipula iridescent virus (TIV) on the basis of the size and morphology of the virion, the production of iridescence in vitro and in infected tipulid larvae, and a serological reaction between antiserum against the virus and an isolate of TIV. A stock of Tipula oleracea was bred in the laboratory. Subjection of larvae to several stress factors did not result in any evidence for activation of a latent virus. Healthy T. oleracea larvae did not develop iridescence when confined in petri dishes with either live TIV-infected larvae or with large amounts of their feces, although these feces were found to contain infective virus by injecting extracts into healthy larvae. It appears that the concentration of virus in the feces of infected larvae is not high enough for them to serve as a source of infection. It was shown that the cadavers of TIV-infected larvae can serve as a source of infection for healthy first- and fourth-instar larvae.

Cations in Hemolymph and Alimentary Tract Tissues of Healthy and Milky Diseased European Chafer (Amphimallon majalis) Larvae1

A study was made of certain cations present in hemolymph and alimentary tract tissues of healthy and diseased European chafer larvae and the spores of Bacillus popilliae collected from diseased hemolymph. The major ions found in the hemolymph, in order of decreasing abundance, were potassium, magnesium, sodium, and calcium. Hemolymph of diseased larvae contained relatively higher concentrations of sodium, potassium, magnesium, iron, and zinc than hemolymph of healthy larvae. Concomitantly, the concentrations of ions were lower in the mid-gut and anterior intestinal tissues of diseased larvae. Only sodium decreased slightly in the diseased tissues of the rectum and rectal sac; other ions remained unchanged or increased. Little or no manganese or copper was detected in the hemolymph or tissues. The major cations of spores of B. popilliae were sodium, calcium, and magnesium. Small amounts of potassium, manganese, copper, iron, and zinc were detected in the spores. Based on calcium and dipicolinic acid determinations of the spores, sufficient calcium was found to allow for the formation of calcium dipicolinate in the expected concentrations.

ウイルス性軟化病蚕に見出された従来よりも小型の球形ウイルス粒子について

ウイルス性軟化病蚕に見出された従来よりも小型の球形ウイルス粒子について