Imperfection works: Survival, transmission and persistence in the system of Heliothis virescens ascovirus 3h (HvAV-3h), Microplitis similis and Spodoptera exigua.

Ascoviruses are insect-specific large DNA viruses that mainly infect noctuid larvae, and are transmitted by parasitoids in the fields. Heliothis virescens ascovirus 3h (HvAV-3h) has been recently isolated from Spodoptera exigua, without parasitoid vector identified previously. Here we report that Microplitis similis, a solitary endoparasitoid wasp, could transmit HvAV-3h between S.

Genome sequence and organization analysis of Heliothis virescens ascovirus 3f isolated from a Helicoverpa zea larva.

The complete genome sequence of Heliothis virescens ascovirus 3f (HvAV-3f) was obtained. The HvAV-3f genome has a circular genome of 198,157bp with a G+C content of 46.0%, and encodes 190 open reading frames (ORFs) longer than 69 amino acids.

A comparison of growth and development of three major agricultural insect pests infected with Heliothis virescens ascovirus 3h (HvAV-3h).

Ascoviruses are double-stranded DNA viruses that are pathogenic to lepidopteran hosts, particularly noctuid larvae. Infection of a larva is characterized by retarded growth, reduced feeding and yellowish body color. In this paper, we reported the growth and development of three major agricultural noctuid insect pests, Helicoverpa armigera (Hübner), Spodoptera exigua (Hübner) and Spodoptera litura (Fabricius), infected with Heliothis virescens ascovirus 3h (HvAV-3h).

Phylogenetic position and replication kinetics of Heliothis virescens ascovirus 3h (HvAV-3h) isolated from Spodoptera exigua.

Insect-specific ascoviruses with a circular genome are distributed in the USA, France, Australia and Indonesia. Here, we report the first ascovirus isolation from Spodoptera exigua in Hunan, China. DNA-DNA hybridization to published ascoviruses demonstrated that the new China ascovirus isolate is a variant of Heliothis virescens ascovirus 3a (HvAV-3a), thus named HvAV-3h.

[Spatial variability and the relationships of soil mineral N and topographic factors in a small watershed].

Objective of this study was to understand the spatial pattern of soil properties and topographic factors and their relationships in a small watershed. We used classical statistical coupling with geo-statistical theory to characterize and compare the spatial variability of soil mineral N and topographic factors in the wind-water erosion crisscross region on the Loess Plateau. The results show that: 1) The nitrate's variable extent is strong while other properties are moderate variability, and the impacts of soil types, land uses on variable extent are significant.