Conservation of two predator species for biological control ofChrysophtharta bimaculata (Col.: Chrysomelidae) in tasmanian forests

Chrysophtharta bimaculata (Olivier) (Coleoptera: Chrysomelidae) is a major defoliator of regeneration eucalypt trees in Tasmania causing a significant reduction in height and diameter increment of trees which reduces wood volume per hectare. A study to conserve and enhance the efficiency of coccinellid species chieflyCleobora mellyi (Mulsant) (Coleoptera: Coccinellidae), and the cantharid,Chauliognathus pulchellus (Macleay) (Coleoptera: Cantharidae), for the biological control ofC. bimaculata was conducted in young regeneration forests in southern Tasmania from 1991–92. Cantharid adults and coccinellid adults and larvae feed onC. bimaculata eggs and, to a lesser extent, young larvae. The study found that coccinellids were more active throughout the egg and early (1^st and 2^nd) stage ofC. bimaculata. The cantharid, however was active only during the egg stage of the prey and then disappeared from the plantation. The coccinellids were therefore the most useful predators, but their population declined when the prey reached the 3^rd and 4^th stages. As shortage of food may account for this decline, supplementary food was provided in the form of sucrose sprays or sugar granules at a feeding station. This resulted in the retention of both predators and particularly the coccinellids and enhanced their efficacy.     

Lysine Succinylation of VBS Contributes to Sclerotia Development and Aflatoxin Biosynthesis in Aspergillus flavus

Aspergillus flavus is a common saprophytic and pathogenic fungus, and its secondary metabolic pathways are one of the most highly characterized owing to its aflatoxin (AF) metabolite affecting global economic crops and human health. Different natural environments can cause significant variations in AF synthesis. Succinylation was recently identified as one of the most critical regulatory post-translational modifications affecting metabolic pathways. It is primarily reported in human cells and bacteria with few studies on fungi. Proteomic quantification of lysine succinylation (Ksuc) exploring its potential involvement in secondary metabolism regulation (including AF production) has not been performed under natural conditions in A. flavus. In this study, a quantification method was performed based on tandem mass tag labeling and antibody-based affinity enrichment of succinylated peptides via high accuracy nano-liquid chromatography with tandem mass spectrometry to explore the succinylation mechanism affecting the pathogenicity of naturally isolated A. flavus strains with varying toxin production. Altogether, 1240 Ksuc sites in 768 proteins were identified with 1103 sites in 685 proteins quantified. Comparing succinylated protein levels between high and low AF-producing A. flavus strains, bioinformatics analysis indicated that most succinylated proteins located in the AF biosynthetic pathway were downregulated, which directly affected AF synthesis. Versicolorin B synthase is a key catalytic enzyme for heterochrome B synthesis during AF synthesis. Site-directed mutagenesis and biochemical studies revealed that versicolorin B synthase succinylation is an important regulatory mechanism affecting sclerotia development and AF biosynthesis in A. flavus. In summary, our quantitative study of the lysine succinylome in high/low AF-producing strains revealed the role of Ksuc in regulating AF biosynthesis. We revealed novel insights into the metabolism of AF biosynthesis using naturally isolated A. flavus strains and identified a rich source of metabolism-related enzymes regulated by succinylation.     

Comparison of Groupings among Members of the Genus Aspergillus Based on Phylogeny and Production of Bioactive Compounds

Three hundred sixty-six Aspergillus strains preserved at the National Institute of Technology and Evaluation (NITE) were compared as to phylogenetic relationships (11 species-clusters) based on the DNA sequences of the D1/D2 domains of LSU rRNA and ITS regions, including the 5.8S rRNA and biological activities of their secondary metabolites. The results showed relatively well correlation between the phylogenetic distribution and the production of bioactive compounds, especially, antimicrobial activities.     

Use of two formulations and two application techniques to deliver Bacillus thuringiensis var. israelensis for the control of Musca domestica (Diptera: Muscidae) larvae and adults in poultry houses

A field study was carried out for 6 wks to assess, from both an efficiency and economic perspective, the effect of individual and integrated success of feeding and topical applications of two formulations of Bacillus thuringiensis var. israelensis (Bti) in controlling house fly (Musca domestica L.) larvae and adults in poultry houses. There was no significant difference between the 1 g and 2 g L^?1 spray applications of Bti. In the absence of spray applications, no significant differences in larval mortalities were observed between the 250 mg and 500 mg kg^?1 feed applications. The percentage mortality of larvae accomplished as a result of using a combination of 250 mg kg^?1Bti feed and 2 g L^?1 spray applications was equivalent to that obtained as a result of combining 500 mg kg^?1Bti and 1g L^?1 spray applications. Treatment with Bti caused significant reductions in the emergence (up to 74%) of house fly adults compared to the control. The fact that the emergence of adult house flies was affected by Bti treatments implies that Bti has sublethal effects on house fly larvae. The cost–benefit analysis (expressed in terms of mortality of larvae growing) indicated that the most effective combination for house fly larvae and adult house fly emergence control was the 500 mg kg^?1 of feed and 2 g L^?1 spray application combination that resulted in 67% larval mortality and a 74% decrease in adult house fly emergence. This study presents commercial users with various alternatives for possible combinations of the two Bti formulations.     

Performance of Two Fruit Fly (Diptera: Tephritidae) Pupal Parasitoids (Coptera haywardi [Hymenoptera: Diapriidae] and Pachycrepoideus vindemiae [Hymenoptera: Pteromalidae]) under Different Environmental Soil Conditions

We evaluated the performance of Coptera haywardi (Ogloblin) (Diapriidae) and Pachycrepoideus vindemiae (Rondani) (Pteromalidae), both hymenopteran pupal parasitoids of Anastrepha spp. (Diptera: Tephritidae). Performance was studied by manipulating the following environmental conditions in the laboratory: (1) soil type, (2) soil moisture content, (3) soil compaction, and (4) depth at which pupae were buried in the soil. There were two experiments: in the first, exposure time of pupae was held constant and in the second, it varied. In the first experiment, C. haywardi was significantly more effective than P. vindemiae in parasitizing fly pupae. With exposure time held constant (36 h), only soil type and pupal burial depth were significantly related to parasitism rates. While P. vindemiae only parasitized pupae located on the soil surface, C. haywardi attacked pupae that were buried up to 5 cm deep, performing better in clayey than in loamy soil. In the second experiment, exposure time (24, 36, 48, and 72 h) had no significant effect on parasitism rates, but soil type did. P. vindemiae again only attacked pupae on the soil surface while C. haywardi was also able to parasitize pupae that were buried up to 5 cm deep. We conclude that C. haywardi represents a viable candidate to replace the environmentally unfriendly P. vindemiae in augmentative biological control programs against fruit flies.