Studies on parasitic castration: Aminopeptidase activity levels and protein concentrations in Ilyanassa obsoleta (mollusca) parasitized by larval trematodes

Specimens of the estuarine prosobranch Ilyanassa obsoleta collected in the vicinity of Charleston, South Carolina, during June, July, and August 1981, were found to be parasitized by larvae of the digeneans Cercaria dipterocerca, Himasthla quissetensis, Lepocreadium setiferoides, Microbilharzia variglandis, Microphalloides nassicola, Stephanostomum tenue, and Zoogonus lasius. The aminopeptidase activity levels and the total protein concentrations of the hemocytes and sera of these infected snails were determined. It was ascertained that snails parasitized by larvae of L. setiferoides had significantly higher levels of hemocytic aminopeptidase activity and hemocytic total protein concentrations than noninfected snails. Furthermore, snails parasitized by L. setiferoides larvae had significantly higher hemocytic levels of aminopeptidase activity than snails parasitized by larvae of S. tenue, Z. lasius, M. nassicola, and H. quissetensis.     

Cross-infection of a nuclear polyhedrosis virus of the almond moth to the indian meal moth

A nuclear polyhedrosis virus isolated from the almond moth, Cadra cautella, was cross-infective to the Indian meal moth, Plodia interpunctella: Concentrations of polyhedra of 8, 16, 32, and 64 × 10³/g of bran diet killed 12, 19, 24, and 45% of the exposed neonate P. interpunctella larvae respectively. Viral replication in P. interpunctella occurred in cell nuclei of the hypodermis, tracheal matrix, fat, Malpighian tubules, in tissue associated with muscles, and in columnar cells of the midgut. However, infection in the alternate host developed more slowly, and the tissue tropisms were less apparent. Also, polyhedra in P. interpunctella were often cuboidal, although they always developed normally in C. cautella. The average number of virions per bundle and the average size of the occluded virions were about the same in both hosts.     

Heterorhabditis sp. (Nematoda: Heterorhabditidae): A Nematode Parasite Isolated from the Banded Cucumber Beetle Diabrotica balteata

A nematode identified as Heterorhabditis sp. was discovered in June 1982 in larval cadavers of the banded cucumber beetle, Diabrotica balteata, in soil on wooded land. Effective beetle control (over 95%) was obtained when larvae were exposed to potted soil containing infective stage nematode juveniles or infected larval cadavers. The nematode was propagated in vivo on larvae of D. balteata, Diaphania nitidalis (the pickleworm), and Galleria mellonella (the greater wax moth). This Heterorhabditis sp. has promising potential as a biocontrol agent for the banded cucumber beetle.     

Histochemical demonstration of melanin in cellular inflammatory processes of penaeid shrimp

Brown-to-black pigment deposits present in association with sites of hemocytic activity in penaeid shrimp (Crustacea, Decapoda) were demonstrated to be melanin by use of histochemical techniques. The brown-black pigment was associated with cellular inflammatory disease processes of infectious and noninfectious etiologies in Penaeus californiensis, P. stylirostris, P. vannamei, and P. duorarum.     

Comparative virulence of Nosema plodiae and Nosema heterosporum in the Indian meal moth, Plodia interpunctella

When larvae of the Indian meal moth, Plodia interpunctella, were fed diets containing spores of Nosema plodiae, the number that survived to the adult stage decreased and the rate of adult emergence was retarded as the concentration of spores was increased; all surviving adults were infected. Also, when larvae were reared on diets containing spores of Nosema heterosporum, the number that survived to the adult stage decreased as the concentration of spores was increased; however, no relationship was apparent between concentration of spores and the rate of adult emergence. The LC₅₀'s of N. plodiae and N. heterosporum were 8.09 × 10⁶ and 4.52 × 10³ spores/g diet, respectively, which confirmed preliminary observations regarding the relative virulence of the two species of Nosema to Indian meal moth larvae.     

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

Host response of two penaeid species, Penaeus aztecus and P. setiferus, from the Gulf of Mexico to the pathogenic fungus Fusarium sp. isolated from the California brown shrimp, P. californiensis, was studied in vivo. The hemocytic response to this fungus was traced histologically in the gills. Both species showed complete resistance to infection by the fungal spores when normal or wounded shrimp were held in seawater containing the spores or when spores were injected directly into the shrimp in low concentrations. Complete melanization and encapsulation of the micro- and macroconidia were observed. Spore dosages of 3.2 × 10⁶ or more were lethal, apparently due to mechanical blockage of the blood sinuses of the gills.     

Hemocytic changes associated with the encapsulation and melanization of some insect parasites

The hemocytic changes that attend parasite encapsulation and melanization in larvae of Drosophila, Musca domestica, and Orthellia caesarion are very similar to those changes occurring in noninfected individuals at metamporhosis. Some of the changes include the precocious differentiation and migration of hemocytes. Comparative and quantitative hemocytological data suggest that some stimulus in infected larvae, acting directly on the hemocytes or on the mechanism(s) controlling their activity, causes the cells to leave areas of the body where they are normally found and to encapsulate parasites. Questions concerning the origin and mode of action of the initial stimulus are raised, and as a basis for future experimentation it is proposed that the cellular immune reactions of these insects against internal metazoan parasites result from a hormonal imbalance.     

Molecular identification of two Trichogramma species (Hymenoptera: Trichogrammatidae) in Korea

Trichogramma wasps parasitize eggs of various insect species. Several Trichogramma species have been commercialized to manage Lepidopteran agricultural pests. Correct species identification is essential for successful biological control. However, the microscopic size and morphological similarity of Trichogramma species makes correct identification very difficult. Internal transcribed spacer (ITS)-2 gene sequences have been used to identify Trichogramma species. Using this molecular marker, Trichogramma species that are commercially available in Korea were identified as Trichogramma ostriniae and Trichogramma brassicae. The latter has not previously been reported in Korea. Additionally, Cadra cautella and Sitotroga cereallela eggs (host eggs of the commercialized Trichogramma species in Korea) were infected with Wolbachia. However, Trichogramma were not infected with the bacterium. This indicates that horizontal transfer of Wolbachia does not occur from host to wasp.     

Microbes from apiarian sources: Bacillus spp. in frass of the greater wax moth

Frass from the greater wax moth, Galleria mellonella, obtained from feral colonies of honey bees, Apis mellifera; from managed honey bee colonies; and from a laboratory culture of the wax moth was sampled for aerobic Gram-positive spore-forming rods. One hundred eighty-five strains belonging to the genus Bacillus were isolated, and most were identified. One hundred and three of the isolates were from frass from the wax moth culture, 61 were from frass from managed honey bee colonies, and 21 were from frass from feral honey bee colonies. The species most frequently isolated varied with the source. Fifty-eight isolates from frass from managed honey bee colonies were B. cereus which was isolated from this source only, but B. sphaericus was the most frequent isolate from frass from the wax moth culture. Bacillus megaterium and organisms belonging to the B. alvei-B. thiaminolyticus spectrum were the most frequent isolates from frass from feral honey bee colonies. Most strains isolated produced caprylate esterase-lipase, leucine aminopeptidase, and phosphoamidase. The numbers of isolates, the species, and the enzymatic activity of the strains varied with the source of the frass. In fact, the complete microbial complement varied with the source. These results are discussed in relation to possible roles of Bacillus spp. in the nutrition of the wax moth as well as the microbial ecology of the honey bee colony.     

THE MACROMOLECULAR PARACRYSTALLINE LATTICE OF INSECT VIRAL POLYHEDRAL BODIES DEMONSTRATED IN ULTRATHIN SECTIONS EXAMINED IN THE ELECTRON MICROSCOPE

Thin sections of polyhedra obtained from gipsy moth larvae infected with P. dispar virus and from silkworm larvae infected with B. mori virus revealed viral particles contained within a pseudohexagonal, macromolecular, paracrystalline lattice. The gipsy moth virus occurs in bundles of one to eight rods enclosed by a limiting membrane. The particles of the silkworm virus, although generally occurring singly, also possess a limiting membrane. The macromolecules appear to be dense, discrete particles when cross-sectioned and to form dense bands by superimposition when longitudinally or obliquely sectioned at certain angles. Calculations of macromolecular size have been made.     

Co-Sensitization to Silkworm Moth (Bombyx mori) and 9 Inhalant Allergens among Allergic Patients in Guangzhou,Southern China

Objectives

This study aimed to investigate the profile of sensitization to silkworm moth (Bombyx mori) and other 9 common inhalant allergens among patients with allergic diseases in southern China.

Methods

A total of 175 patients were tested for serum sIgE against silkworm moth in addition to combinations of other allergens: Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blomia tropicalis, Blattella germanica, Periplaneta americana, cat dander, dog dander, Aspergillus fumigatus and Artemisia vulgaris by using the ImmunoCAP system. Correlation between sensitization to silkworm moth and to the other allergens was analyzed.

Results

Of the 175 serum samples tested, 86 (49.14%) were positive for silkworm moth sIgE. With high concordance rates, these silkworm moth sensitized patients were concomitantly sensitized to Dermatophagoides pteronyssinus (94.34%), Dermatophagoides farinae (86.57%), Blomia tropicalis (93.33%), Blattella germanica (96.08%), and Periplaneta americana (79.41%). Moreover, there was a correlation in serum sIgE level between silkworm moth and Dermatophagoides pteronyssinus (r = 0.518), Dermatophagoides farinae (r = 0.702), Blomia tropicalis (r = 0.701), Blattella germanica (r = 0.878), and Periplaneta americana (r = 0.531) among patients co-sensitized to silkworm moth and each of these five allergens.

Conclusion

In southern Chinese patients with allergic diseases, we showed a high prevalence of sensitization to silkworm moth, and a co-sensitization between silkworm moth and other five common inhalant allergens. Further serum inhibition studies are warranted to verify whether cross-reactivity exists among these allergens.     

Pathology of a nuclear polyhedrosis virus of the alfalfa looper in alternate hosts

The symptomatology and histopathology of a nuclear polyhedrosis virus isolated from a larva of the alfalfa looper, Autographa californica, was studied by examining 13 tissues in the original and following alternate hosts: cabbage looper, Trichoplusia ni; beet armyworm, Spodoptera exigua; saltmarsh caterpillar, Estigmene acrea; corn carworm, Heliothis zea; cotton leafperforator, Bucculatrix thurberiella; and diamondback moth, Plutella xylostella. In all hosts, the hypodermal, tracheal matrix, and fat body cells were infected. Other tissues infected in some hosts included the Malpighian tubules, muscle, hemocytes, ganglia, midgut, hindgut, juvenile tissue (imaginal buds), and testes. No major changes in tissue tropisms were observed. The external symptoms were typical of nuclear polyhedrosis in all species except the corn earworm; in this host, development of the disease and death were delayed.     

Wolbachia variant that induces two distinct reproductive phenotypes in different hosts

Wolbachia is an intracellular endosymbiont that induces a variety of reproductive alterations in diverse arthropods. The almond moth, Cadra cautella, is double infected with two Wolbachia variants, wCauA and wCauB, and expresses complete cytoplasmic incompatibility (CI). The individual contribution of wCauA and wCauB to the expression of CI are unclear, however, because the two variants have not been separated in this host. The effect of wCauA is of particular interest because it induces male killing when transferred into the Mediterranean flour moth, Ephestia kuehniella. In the present study, we generated C. cautella infected with only wCauA by treating double-infected insects with tetracycline. Single-infected C. cautella exhibited strong CI, demonstrating that wCauA induces two distinct reproductive phenotypes in different hosts: CI in C. cautella and male killing in E. kuehniella. CI was also observed in the cross of double-infected males and single-infected females. Comparison of the single- and double-infected insects by real-time quantitative polymerase chain reaction suggested that the wCauA density is not affected much by the presence or absence of wCauB.     

Histopathology of the European chafer,Amphimallon majalis,infected with Bacillus popilliae

Third-instar larvae of the European chafer were challenged orally or by injection with spore suspensions of Bacillus popilliae. The pathogenesis was investigated by histological examination of larvae sacrificed at various exposure times. Spores germinated in the center of hemocytic capsules when injected and probably in the lumen of the anterior intestine when ingested. Following preliminary multiplication inside the basement membrane of the midgut, vegetative cells penetrated and continued to multiply in the hemolymph. Whether larvae were infected by ingestion or injection, the bacilli concentrated in connective tissue sheaths or in close association with hemocytes for sporulation.     

Antennal resolution of pulsed pheromone plumes in three moth species

Male antennae of Cadra cautella,Pectinophora gossypiella, and Spodoptera exigua were presented with 20-ms-duration pulses of their two-component pheromone at rates of 1 to 33 Hz. Fourier analyses of electroantennograms resolved the temporal structure of trains of pheromone filaments delivered at up to 33 Hz for C. cautella and S. exigua and 25 Hz for P. gossypiella. Pheromone components tested separately for each species were generally equivalent in filament resolution to complete blends. Ambient temperatures of 18, 23 and 28 °C affected filament resolution only slightly, with poorer ability to discriminate rapidly pulsed signals at 18 °C. The question of how, or indeed if, such frequencies are conserved beyond the peripheral nervous system, remains.     

Orientation of field populations ofBrachymeria intermedia [Hym.: Chalcididae], to host and host-habitat cues

Brachymeria intermedia (Nees), a pupal parasitoid of the gypsy moth, was caught in the field using plexiglas traps coated with Tangletrap (2). Significantly greater numbers of females were collected in traps baited with gypsy moth pupae than in traps with male or femaleB. intermedia or traps painted yellow.B. intermedia collected in traps during the first 3 weeks of native gypsy moth pupation were primarily female. A preponderance of males were caught during the fourth week. The hyperparasite,Brachymeria compsilurae (Cwfd) was also trapped in small numbers. Gypsy moth pupae were hung in interior and exterior areas of woodland sites. A greater number ofB. intermedia emerged from pupae in woodland edge sites than from pupae in interior woodland sites.     

Encapsulation of a parasitoid egg within its habitual host: An ultrastructural investigation

Eggs of the ichneumonid parasitoid Campoletis sonorensis oviposited within its natural host Heliothis virescens are rarely encapsulated. The chorion of eggs deposited within the natural host were ultrastructurally similar to eggs within the lateral oviduct. Less than 5% of eggs incubated in invertase or saline and injected into the host evoked a hemocytic response within 24 hr; however, all the eggs incubated in either protease or lipase prior to injection evoked a hemocytic reaction in the host within 24 hr. It would appear that encapsulation of eggs incubated in either lipase or protase resulted from modification of the chorion surface. Eggs incubated in invertase or saline were encapsulated within 72 to 96 hr while eggs incubated in the fluid from the female parasitoid oviduct were not. The ultrastructural development of the hemocytic capsule is presented and the possible role of cell contacts in capsule regulation is discussed.     

Insecticidal activity of spore-free mutants of Bacillus thuringiensis against the Indian meal moth and almond moth

Three oligosporogenic mutants of Bacillus thuringiensis were assayed for toxicity against larvae of the Indian meal moth, Plodia interpunctella, and the almond moth, Ephestia cautella. The results were compared with insecticidal activity obtained from the parent strain (HD-1) and two standard B. thuringiensis formulations (HD-1-S-1971 and HD-1-S-1980) against the same insect species. The toxicity of the sporeless mutant preparations was significantly diminished against the Indian meal moth (10- to 26-fold increase in LC₅₀) but exceeded the toxicity of the standards against the almond moth. The toxicities of the B. thuringiensis preparations toward the Indian meal moth were consistent with the number of spores in the test samples, but spores did not contribute to toxicity to E. cautella larvae. A rationale for basing dosage on soluble protein was demonstrated for use in situations where spores are not a contributing factor in toxicity.