Nudivirus Sequences Identified from the Southern and Western Corn Rootworms (Coleoptera: Chrysomelidae)

Analysis of pooled genomic short read sequence data revealed the presence of nudivirus-derived sequences from U.S. populations of both southern corn rootworm (SCR, Diabrotica undecimpunctata howardi Barber) and western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte). A near complete nudivirus genome sequence was assembled from sequence data for an SCR population with relatively high viral titers. A total of 147,179 bp was assembled from five contigs that collectively encode 109 putative open reading frames (ORFs) including 20 nudivirus core genes. In contrast, genome sequence recovery was incomplete for a second nudivirus from WCR, although sequences derived from this virus were present in three geographically dispersed populations. Only 48,989 bp were assembled with 48 putative ORFs including 13 core genes, representing about 20% of a typical nudivirus genome. Phylogenetic analysis indicated that both corn rootworm nudiviruses grouped with the third known nudivirus of beetles, Oryctes rhinoceros nudivirus in the genus Alphanudivirus. On the basis of phylogenetic and additional analyses, we propose further taxonomic separation of nudiviruses within Alphanudivirus and Betanudivirus into two subfamilies and five genera. Identification of nudivirus-derived sequences from two species of corn rootworm highlights the diversity of viruses associated with these agricultural insect pests.

Diabrotica undecimpunctata virus 2, a Novel Small RNA Virus Discovered from Southern Corn Rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae)

ABSTRACT The genome of Diabrotica undecimpunctata virus 2 (DuV2), a putative positive-sense, single-stranded RNA virus identified from the southern corn rootworm transcriptome, comprises 5,313 nucleotides, including a short poly(A) tail. The two open reading frames encode a nonstructural polyprotein (p156) and a putative capsid protein (p25).

Genome Sequence of a Small RNA Virus of the Southern Corn Rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae)

ABSTRACT The genome sequence of a novel small RNA virus, tentatively named Diabrotica undecimpunctata virus 1 (DuV1), was discovered from the transcriptome of the southern corn rootworm, Diabrotica undecimpunctata howardi Barber. DuV1 has a positive-sense, single-stranded RNA genome that encodes a single polyprotein of 3,401 amino acids with limited similarity to other viruses.

Striped Cucumber Beetle Acalymma vittatum F. (Insecta: Coleoptera: Chrysomelidae)

The striped cucumber beetle, Acalymma vittatum F. (Figure 1) is a serious agricultural pest of plants in the family Cucurbitaceae in eastern North America. Crops affected by larval and adult feeding include cucumber, Cucumis sativus L., cantaloupe, Cucumis melo L., pumpkin, Cucurbita pepo L., and other Cucurbita spp. (Dill and Kirby 2016). The striped cucumber beetle is a vector of the plant disease bacterial wilt (Eaton 2016). Though the striped cucumber beetle occurs throughout Florida, it is the least commonly reported among three chrysomelid species on cucurbit crops in the state. The spotted cucumber beetle, Diabrotica undecimpunctata howardi Barber, and banded cucumber beetle, Diabrotica balteata LeConte, are more common in Florida, causing damage symptoms that are similar to striped cucumber feeding damage (Webb 2010). Includes: Introduction - Distribution - Description and Life Cycle - Damage - Monitoring - Management - Selected References.https://edis.ifas.ufl.edu/in1215 Also published at http://entnemdept.ufl.edu/creatures/VEG/BEAN/striped_cucumber_beetle.html

Influence of Planting Pattern on Pest Management in Virginia Market Type Peanut (Arachis hypogaea L.)

ABSTRACT Twelve field trials were completed in North Carolina from 2005 to 2007 to determine the impact of planting pattern on peanut yield, market grade characteristics, and pest reaction for the Virginia market type cultivars Perry and VA 98R. The first set of experiments was designed to evaluate incidence of Cylindrocladium black rot (caused by Cylindrocladium parasiticum) using a factorial treatment arrangement of two cultivars, two levels of fumigation (none or metam sodium at 112 L/ha), and two levels of planting pattern (single rows spaced 91-cm apart or twin rows spaced 18 cm apart on 91-cm centers). Visible symptoms associated with Cylindrocladium black rot were not affected by planting pattern. However, in 1 of 3 trials pod scarring as a result of feeding by southern corn rootworm (Diabrotica undecimpunctata Howardi) was greater in twin rows compared with single rows. Damage from tobacco thrips (Frankliniella fusca) was also higher in the cultivar VA 98R planted in twin rows than in single rows or for the cultivar Perry. In the second set of experiments designed to evaluate incidence of Sclerotinia blight (caused by Sclerotinia minor), a factorial treatment arrangement consisting of two cultivars, two levels of boscalid (none or boscalid at 0.44 kg ai/ha), and two levels of planting pattern was implemented. Boscalid decreased Sclerotinia blight incidence at one of 4 locations, and increased pod yield. Yield of Perry was lower when grown in twin rows versus single rows, but yield of VA 98R was higher in twin rows. Peanut planted in twin rows yielded more than peanut planted in single rows regardless of cultivar, fumigation, or disease history in most trials. Results from these experiments suggest that planting pattern can have a minor impact on response to pests and that yield and market grades are often improved when peanut is planted in twin-row planting patterns compared with single rows.

Synthesis of corn rootworm pheromones from commercial diols

A mixture of stereoisomers of the corn rootworm pheromones was synthesised via the Grignard coupling of protected bromohydrins with alkylcuprate as a key step. The synthesis of 8-methyldec-2- yl propanoate (I ), the northern corn rootworm Diabrotica longicornis Say pheromone, was achieved from pentane-1,5-diol in four steps with an overall yield of 35.1 % and 10-methyltridecan-2-one (II ), the southern corn rootworm Diabrotica undecimpunctata howardi Barber pheromone, was synthesised from octane-1,8-diol as commercially available starting material in five steps with an overall yield of 28.7 %.