College of Tropical Agriculture and Human Resources

About: College of Tropical Agriculture and Human Resources is a based out in . It is known for research contribution in the topics: Population & Soil water. The organization has 513 authors who have published 604 publications receiving 15798 citations.

Lobate lac scale, Paratachardina pseudolobata (Hemiptera: Keriidae), in Hawaii's urban landscape: Hosts and management

Abstract: The lobate lac scale, Paratachardina pseudolobata Kondo & Gullan, is a recent insect invader to Hawaii that was first found in October 2012 on Oahu, Hawaii. It infests young branches of woody plants (usually less than 2 cm in diameter), forming a mass that appears as a dark crust, resulting in an unhealthy appearance, defoliation of leaves, and death of some plant species. This insect has infested many native and non-native plant species on Oahu, and the number of infested plant species is increasing. Our recent survey results, reported in this article, revealed 28 new host plant species in addition to 83 host species that we had reported previously, making 111 host plant species in Oahu’s urban landscape. Efficacy and longevity of preventive treatment using the systemic insecticides imidacloprid and emamectin benzoate, delivered through trunk injection, against lobate lac scale on Chinese banyan, Ficus microcarpa, and curative treatment using imidacloprid on weeping banyan, Ficus benjamina, were evaluated. Forty-five Chinese banyans and 10 weeping banyans were included in this study. Our findings suggest that imidacloprid delivered via trunk injection is effective in preventing lobate lac scale infestation for at least 22 months post-treatment, and also in reducing lobate lac scale infestation curatively for at least 20 months post-treatment. This study provides an update on lobate lac scale’s host species in Hawaii’s urban landscape, and an effective preventive and curative management strategy against this pest.

Potential Dual Role of West Nile Virus NS2B in Orchestrating NS3 Enzymatic Activity in Viral Replication.

Abstract: West Nile virus (WNV) nonstructural protein 3 (NS3) harbors the viral triphosphatase and helicase for viral RNA synthesis and, together with NS2B, constitutes the protease responsible for polyprotein processing. NS3 is a soluble protein, but it is localized to specialized compartments at the rough endoplasmic reticulum (RER), where its enzymatic functions are essential for virus replication. However, the mechanistic details behind the recruitment of NS3 from the cytoplasm to the RER have not yet been fully elucidated. In this study, we employed immunofluorescence and biochemical assays to demonstrate that NS3, when expressed individually and when cleaved from the viral polyprotein, is localized exclusively to the cytoplasm. Furthermore, NS3 appeared to be peripherally recruited to the RER and proteolytically active when NS2B was provided in trans. Thus, we provide evidence for a potential additional role for NS2B in not only serving as the cofactor for the NS3 protease, but also in recruiting NS3 from the cytoplasm to the RER for proper enzymatic activity. Results from our study suggest that targeting the interaction between NS2B and NS3 in disrupting the NS3 ER localization may be an attractive avenue for antiviral drug discovery.

Complete genome sequence of a distinct calla lily chlorotic spot virus isolated in mainland China.

Abstract: The first complete genome sequence of calla lily chlorotic spot virus (CCSV) from Lijiang in northwestern Yunnan Province was obtained using RT-PCR with designed primers. The genome of CCSV isolate LJ-1-Yunnan is tripartite. The small (S) RNA is 3182 nucleotides (nt) in length and encodes a nonstructural protein (NSs, 1383 nt) and a nuclear nucleocapsid (N, 834 nt), separated by an 836-nt intergenic region (IGR). The medium (M) RNA is 4749 nt in length and encodes a nonstructural movement protein (NSm, 930 nt) and a glycoprotein (GnGc, 3,372 nt), also separated by a 349-nt IGR. The large (L) RNA is 8912 nt in length and encodes a predicted RNA-dependent RNA polymerase (RdRp, 8652 nt). The nucleotide sequences of the three viral RNA segments are 92-94 % identical to the published CCSV genome sequence, and the amino acid sequences of the encoded proteins are 96-98 % identical. However, the IGRs of the S and M RNAs are less similar, with 86 and 72 % identity, respectively. Genome sequence comparisons and phylogenetic analysis indicate that the Lijiang CCSV isolate is a unique tospovirus isolate that differs from CCSV isolates in other geographic regions.

Confirmation of Paracercospora egenula causing leaf spot of eggplant in Hawaii

Abstract: Morphological and molecular studies confirmed Paracercospora egenula as the primary cercosporoid fungus causing leaf spot of eggplant (Solanum melongena) in Hawaii. This is the first confirmed record of P. egenula in Hawaii, although it was previously reported as C. solani-melongenae, based on an interception at Oahu, Hawaii, in 1946. Another cercosporoid species, Cercospora melongenae, reported to cause leaf spot on eggplant in Hawaii, was not detected.

First Report in Hawai'i of Xanthomonas citri pv. mangiferaeindicae Causing Bacterial Black Spot on Mangifera indica.

Abstract: Bacterial black spot of mango (Mangifera indica) caused by Xanthomonas citri pv. mangiferaeindicae (Xcm), is an economically important disease in tropical and subtropical areas (3). Xcm can infect a wide range of mango cultivars and induces raised, angular, black leaf lesions, sometimes with a chlorotic halo. Fruit symptoms appear as small, water-soaked spots on the lenticels that become star-shaped, erumpent, and exude an infectious gum (3). The bacterium can also cause latent infections (2). Immature mango fruit with black spots on the epidermis were collected in August 2012 from mango trees of the cvs. Raposa and Pirie at a residence in Pukalani, Hawai'i, on the island of Maui. Similar symptoms were seen on a tree of the mango cv. Common (also known as ‘Spanish’ or ‘Lahaina’) at a nearby golf course. Mango fruit with black lesions, and leaves showing black lesions with yellow halos, were collected in August 2012 from mango trees of the cv. Haden at a residence in Kaimuki, Hawai'i, on the island of O'ah...