Characterization of Nuclear Polyhedrosis Virus DNAs

The nuclear polyhedrosis virus DNAs characterized and compared in this study consist of the singly-enveloped nucleocapsids (SNPV) of Trichoplusia ni and the bundles of nucleocapsids common to a single envelope (MNPV) from Spodoptera frugiperda and Rachiplusia ou. The SNPV and MNPV DNAs are very similar in hydrodynamic properties and molecular weights. In addition, the NPV DNAs are similar in size to those extracted from the granulosis viruses that infect T. ni and S. frugiperda. As isolated from purified virus or directly from occluded virus, the nuclear polyhedrosis virus DNAs consist of a mixture of about 20 to 30% double-stranded covalently closed molecules and approximately 60% relaxed circles, with less than 10% in linear duplex form. The molecular weights of all nuclear polyhedrosis virus DNAs as compared in this study are slightly smaller than those of T4 bacteriophage DNA and perhaps slightly smaller than those of the granulosis virus DNAs. The best estimates of these molecular weights by neutral sucrose sedimentation for the nuclear polyhedrosis viruses range from 90 to 100 x 10(6) relative to a size of 108 x 10(6) for T4 DNA. The base compositions of the nuclear polyhedrosis viruses that infect T. ni and S. frugiperda are compared with the respective insect host DNAs.     

Characterization of Gypsy Moth (Lymantria dispar) Nuclear Polyhedrosis Virus

Characterization of the proteins and nucleic acid of the gypsy moth nuclear polyhedrosis virus isolated in Ithaca, N.Y. (LdNPV-IT) is presented. A total of 29 viral structural proteins were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis when the virus was isolated in the absence of alkaline protease activity. Fourteen surface envelope viral proteins were identified by lactoperoxidase iodination. Eleven proteins were associated with nucleocapsids prepared by Nonidet P-40 detergent treatment. Distinct alterations of viral proteins were documented when virions were purified in the presence of occlusion body-associated alkaline protease(s). Restriction enzyme digests of viral DNA indicated that this isolate was composed of a large number of genetic variants. On the basis of the major molar fragments resulting from EcoRI, BamHI, BglII, and HindIII digests, the molecular weight of the LdNPV genome was approximately 88 × 10⁶.     

Nuclear Polyhedrosis Virus and Resistant Corn Silks Enhance Mortality of Corn Earworm (Lepidoptera: Noctuidae) Larvae

Plant resistance to insects, specifically antibiosis, offers a biologically, economically, and environmentally sound alternative to pesticides for controlling the corn earworm, Helicoverpa zea (Boddie), in corn, Zea mays L. Our study included a series of experiments to evaluate the effects of resistant and susceptible silks incorporated into pinto bean diets on the infectivity of a nuclear polyhedrosis virus (Elcar) applied to the surface of diet with and without formalin. Neonate, 4- and 8-day-old corn earworm larvae were tested. The combination of Elcar and resistant corn silks increased mortality of the corn earworm neonates. When resistant silks were tested in diet without formalin, the surface of the diet darkened and the neonates tended to burrow into the diet to feed, reducing the amount of virus consumed and hence mortality. After feeding on diets containing resistant silks for 4 or 8 days, earlier and higher mortality was associated with lower weight of larvae that were exposed to Elcar. Elcar caused 49% (diet with formalin) and 87% (diet without formalin) mortality of the 8-day-old larvae that had fed on the resistant silk diets as opposed to 0 and 3% mortality for larvae that had fed on diets without the resistant silks prior to treatment with the virus. Our results demonstrate that resistant corn silks and Elcar are compatible approaches for controlling corn earworm larvae.     

Characterization of six microsatellite loci in the African wild silk moth (Gonometa postica,Lasiocampidae)

Six microsatellite markers were developed for the African wild silk moth, Gonometa postica (Lasiocampidae), using an enrichment protocol. The total number of alleles ranged from three to 17 for a sample of 130 individuals across the distribution of the species. Observed levels of heterozygosity ranged from 0.17 to 0.78. Deviation from Hardy–Weinberg equilibrium detected in some loci is probably the result of large interannual population size fluctuations characteristic of this species. No evidence of linkage disequilibrium was detected among loci. These loci will be useful for the inference of demographic processes in a moth species that is of potential economic importance.     

Parasitoids of the African wild silkmoth,Gonometa postica (Lepidoptera: Lasiocampidae) in the Mwingi forests,Kenya

Gonometa postica Walker produces silk of high quality, but it is affected by parasitoids attack. A study on the parasitism of G. postica larvae and pupae on host and non‐host plants were undertaken for the first and second generations, corresponding to the long (March–May) and short (October–December) rainy seasons in 2006 at six field sites, three each in the Imba and Mumoni forests of Mwingi, eastern Kenya. All freshly spun cocoons of G. postica were sampled at each site from a total of 100 trees of host plants and other non‐host plants where they have migrated before pupation. The cocoons were kept individually in fine net‐sealed plastic vials to determine percentage parasitism. Two dipterans and four hymenopteran larval–pupal parasitoids were identified from the two forests. The most common parasitoids were Palexorista sp. (Diptera: Tachinidae) and Goryphus sp. (Hymenoptera: Ichneumonidae) with parasitism ranging from 1.8 to 32.7% and 2.2 to 7.5%, respectively. Parasitism varied significantly according to host or non‐host plants, seasons and sites. This study indicates that, of the six parasitoid species recovered, only two had a significant impact in reducing the quality of the cocoons.     

Nuclear polyhedrosis virus as a biological control agent for Malacosoma americanum (Lepidoptera: Lasiocampidae)

In addition to damaging trees, the eastern tent caterpillar is implicated in early fetal loss and late‐term abortion in horses. In a field study, we evaluated the potential biological control of the caterpillar using eastern tent caterpillar nuclear polyhedrosis virus (ETNPV), a naturally occurring virus that is nearly species‐specific. Egg masses were hatched and second instar larvae were fed virus‐inoculated foliage to propagate the virus in vivo. Then, a viral pesticide was formulated at concentrations of 10⁴, 10⁶ and 10⁸ polyhedral inclusion bodies per ml. The pesticide was applied to foliage on which second, third and fourth instar caterpillars were feeding. When the majority of surviving larvae reached the sixth instar, colonies were collected and the surviving caterpillars counted. Mean numbers of surviving caterpillars per treatment were compared via 95% bootstrap confidence intervals. The data indicate second instar caterpillars were highly susceptible to the virus, but only at the highest concentration tested. Third instar caterpillars were also somewhat susceptible to high virus concentrations, while fourth instar caterpillars were fairly resistant. Our data provide the strongest evidence to date that ETNPV can be propagated, harvested and refined for formulation as a biological control agent for eastern tent caterpillar. Its use on this insect may be merited in circumstances where landowners and managers need to protect trees and horses.     

Characterization of a Granulovirus Isolated from Epinotia aporema Wals. (Lepidoptera: Tortricidae) Larvae

A granulovirus (GV) isolated from Epinotia aporema (Lepidoptera: Tortricidae)—a major soybean pest—was studied in terms of its main morphological, biochemical, and biological properties. The ovoidal occlusion bodies were 466 by 296 nm in size, and their most prominent protein had an apparent molecular mass of 29 kDa. Its amino-terminal sequence was remarkably homologous to that of the granulins of other GVs. The DNA genome size was estimated to be 120 kbp. The high specificity and pathogenicity of this newly described granulovirus (EpapGV) indicate that it is indeed a good candidate for the biological control of this pest.     

两株粘虫核型多角体病毒理化性质的比较研究

电镜观察粘虫(Leucania separala)核型多角体病毒的不同株系内蒙株(简称N株)和阜阳株(简称F株)的多角体、病毒粒子及核衣壳在形态大小方面都没有很大差别,DNA分子大小也相近。但在SDS-PAGE多肽图谱及DNA酶切图谱上则表现出一定的差异。经SDS-PAGE所得病毒粒子多肽图谱N株有17条多肽,F株有19条多肽。两株病毒DNA经BamHI酶切N株获得7条带,F株则有8条带,说明DNA酶切位点不尽相同。据此,生化分析能更快速、准确地进行株系分类。     

Notes on synonymy of African Lasiocampidae (Lepidoptera)

Eighteen new synonyms are established based on studying the type specimens: Beralade sobrina (Druce, 1900) = Labea fulvostriata Pagenstecher, 1903 syn. n., Catalebeda jamesoni Bethune-Baker, 1908 = Catalebeda tamsi Hering, 1932 syn. n., Gastroplakaeis forficulatus Möschler, 1887 = Gastroplakaeis toroensis Bethune-Baker, 1927 syn. n., Gastroplakaeis parinarii (Guérin-Meneville, 1867) comb. n. = Gastroplakaeis schultzei Aurivillius, 1905 syn. n. = Taragama punctifera Riel, 1911 syn. n. = Gastroplakaeis flaveola Closs, 1917 syn. n. = Gastroplakaeis agroeca Hering, 1928 syn. n., Leipoxais emarginata Aurivillius, 1911 = Leipoxais philopseudia Hering, 1928 syn. n., Leipoxais major Holland, 1893 = Leipoxais alazon Hering, 1928 syn. n., Leipoxais obscura Aurivillius, 1908 = Lasiocampa noctis Druce, 1910 syn. n., Leipoxais strandi Aurivillius, 1927 = Leipoxais dyaresta Hering, 1928 syn. n. = Leipoxais castanea Tams, 1929 syn. n., Leptometa sapelensis Aurivillius, 1927 stat. n. = Leptometa irrorata Tams, 1929 syn. n., Mallocampa audea Druce, 1888 = Mallocampa jaensis Bethune-Baker, 1927 syn. n., Pseudometa choba Druce, 1899 = Glocia tenebra Bethune-Baker, 1911 syn. n. = Pseudometa nigricans Aurivillius, 1925 syn. n., Ptyssophlebia discocellularis (Strand, 1912) comb. n. = Catalebeda elegans Aurivillius, 1925 syn. n. = Ptyssophlebia avis Berio, 1937 syn. n. Two subspecies are raised to the rank of species: Leptometa sapelensis Aurivillius, 1927 stat. n. and Ptyssophlebia meridionalis (Tams, 1936) stat. n. et comb. n. New combinations are found: Gastroplakaeis parinarii (Guérin-Meneville, 1867) comb. n., Ptyssophlebia discocellularis (Strand, 1912) comb. n., P. meridionalis (Tams, 1936) stat. n. et comb. n., and P. intermedia (Aurivillius, 1925) comb. n. Lectotypes are designated for Leipoxais strandi Aurivillius, 1927 and Leipoxais major Holland, 1893, and a neotype, for Lasiocampa parinarii Guérin-Meneville, 1867.     

Peculiarities of island endemism in Lasiocampidae (Lepidoptera)

The distinctive features of island endemism in Lasiocampidae are extensive adaptive radiation and vicariance. These phenomena are especially typical of archipelagoes, where different taxa occur on closely located islands. The diverse ecological conditions of the islands determine the presence of a great number of subordinate taxa. Owing to the reduced flight activity, the species of Lasiocampidae are characterized by a high level of endemism on isolated islands. Islands of continental origin (Sumatra, Borneo) have a lower level of endemism, with centers on the mountain ranges. The endemism level is much higher in islands of biogenic origin (the Philippines). The Pacific islands have a higher index of specific endemism. At the same time, the islands of mixed and oceanic origin have low species diversity by a large fraction of endemic taxa. The boundaries of species distribution are determined not only by the landscape or climatic factors but also by biological ones.     

A new genus of African Lasiocampidae (Lepidoptera)

The species Gastroplakaeis idakum Bethune-Baker, 1913, G. balia Tams, 1929, and G. elongata Hering, 1941 are transferred from the genus Gastroplakaeis Möschler, 1887 into the newly erected genus Weirdonia gen. n. (the type species is Gastroplakaeis idakum Bethune-Baker, 1913), and corresponding new combinations are established. New species, Weirdonia baccara sp. n. and W. hypocrita sp. n. (type locality: Democratic Republic of the Congo), W. murena sp. n. (type locality: Northern Nigeria), and W. helicea sp. n. (type locality: Gabon) are described. A new synonymy is established: Gastroplakaeis balia Tams, 1929 = Gastroplakaeis elongata Hering, 1941 syn. n. Diagnoses and distribution maps are given for all the species.     

Biological Characterization of a Nucleopolyhedrovirus of Spodoptera litura (Lepidoptera: Noctuidae) Isolated from the Philippines

A Philippine Spodoptera litura nucleopolyhedrovirus (SltMNPV) was isolated by plaque purification from an uncloned NPV population in a formulated product that exhibits high insecticidal activity against the onion-attacking common cutworm, S. litura. Its estimated genome size was approximately 142 kb. Comparison with Autographa californica MNPV and Spodoptera exigua NPV by restriction fragmentation analysis showed that it was a distinct isolate. Light microscopy examination showed that SltMNPV-P7 infected insect cell lines derived from Spodoptera littoralis (CLS-79), Spodoptera frugiperda (Sf9), and S. litura (TUAT-SpLi221). It produced typical cytopathic effects in cell lines established from Bombyx mori and S. exigua and induced apoptotic-like cytopathology in Lymantria dispar-derived cell line; it exerted no observable cytopathic effect on Spilosoma imparilis cell line. Significant increase in budded virus (BV) production was observed in CLS-79, Sf9, and TUAT-SpLi221 cell lines, in which TUAT-SpLi221 cell line supported the highest BV titer. No significant BV production was observed in the remaining four cell lines. Similarly, viral DNA replication and polyhedrin production proceeded only in these three spodopteran cell lines. Results showed that SltMNPV-P7 is a unique isolate which can be propagated in vitro for further studies and thus has a potential for development into a more effective microbial insecticide.     

栗黄枯叶蛾核型多角体病毒的分离与鉴定

栗黄枯叶蛾（Trabala vishnou Lefebure)属卷叶蛾属,危害10多种果树和林木花卉。1989年我们从四川大学校园内自然罹病死亡的大量栗黄枯叶蛾幼虫中,分离到一种栗黄枯叶蛾病原物。经纯化后,通过感染试验,涂片染色,电镜形态观察,超微结构研究,组织病理研究等,确认 该病原物为一种核型多角体病毒。     

茶尺蠖核型多角体病毒制剂的试制与推广应用

试制了茶尺蠖病毒水剂、茶尺蠖病毒Bt混剂、茶尺蠖病毒农药混剂 ,三种制剂的室内毒效和田间防治效果均在 90 .1%以上 ,1999年～ 2 0 0 0年推广应用面积 3万亩 ,取得了良好的经济效益和社会效益。     

红棕灰夜蛾核型多角体病毒的研究

红棕灰夜蛾 Sarcopolia illoba(Butler)是鳞翅目夜蛾科害虫。分布于我国东北、华北、华东、华中及苏联、日本、朝鲜、印度等地。幼虫多食性,为害烟草、甘蓝、马铃薯、甜莱、大豆、豌豆、菜豆等作物。1984年在哈尔滨大豆田中,从该虫幼虫自然死虫体内分离出一株核型多角体病毒。我们对该病毒的形态学进行了观察。这种病毒在国内外尚未见报道。并对12种夜蛾科害虫:迹幽夜蛾(Discestra stigmosa)、甘蓝夜蛾(Mamestra brassicae)、黄地老虎(Scotia segetum)、小地老虎(S.ipsilon)、银纹夜蛾     

我国蚊虫分离的一种新型胞质多形体病毒

0507BS3是从中国新疆喀什地区采集的库蚊和按蚊混合蚊标本分离的病毒株,对C6/36细胞致病变而对Ve-ro和BHK-21细胞不致病变。电镜观察显示病毒颗粒呈圆球形,直径约60nm(n=20),无包膜,单层衣壳,衣壳内有中央核。基因组核酸电泳显示基因组包括10条双链RNA(double stranded RNA,dsRNA)片段。病毒第10基因片段核酸序列测定显示该片段全长964bp(GenBankID:FJ150869),具有单一开放读码框,编码长度为275个氨基酸的蛋白,分子量约30.8kD。病毒第10基因片段核酸序列比对未发现相似的病毒核酸序列,氨基酸序列与胞质多形体病毒(Cytoplasmic polyhedrosis virus,CPV)第10基因片段编码的多形体蛋白部分区段匹配。病毒第10基因片段和已知各型CPV第10基因片段核酸序列共同进行系统进化分析显示该病毒位于独立的进化分枝,提示0507BS3病毒可能是一种新型CPV病毒。     

Seven new monotypic genera of African Lasiocampidae (Lepidoptera)

New monotypic genera are established for African Lasiocampidae: Hecata gen. n. (type species Megasoma splendens Druce, 1887), Selena gen. n. (type species Megasoma vesta Druce, 1887), Tragoptyssa gen. n. (type species Streblote flavimaculata Tams, 1929), Ammacosola gen. n. (type species Beralade pygmula Strand, 1911), Scythropa gen. n. (type species Pseudometa schultzei Aurivillius, 1905), and Cryptopacha gen. n. (type species Metanastria porphyria Holland, 1893), as well as Pellecebra gen. n. for the new species Pellecebra superba sp. n. (type locality is the Democratic Republic of the Congo). New species combinations are also introduced, and new synonymy is established: Pseudometa schultzei Aurivillius, 1905 = Pseudometa scythropa Hering, 1928, syn. n.