Conopomorpha sinensis Bradley is a host-specific pest of Litchi chinensis and Euphoria longan. Here, we demonstrated that C. sinensis has evolved special physical and chemical mechanisms for host plant location that enable it to survive and reproduce. Females favored laying their eggs on the convex surface of litchi fruit that had particular volatile characteristics. Experiments using a H-type olfactometer showed that female C. sinensis were attracted to litchi flowers, tender shoots, immature fruits, and mature fruits, with the highest attraction rate to mature fruits (74.67 ± 2.31%). There were no significant differences in the attraction of male C. sinensis to different litchi tissues. Further oviposition preference tests using the pericarp, pulp, and seeds of mature litchi fruits revealed that female C. sinensis prefer to lay their eggs on the pericarp. Litchi volatiles were found to be important in attracting C. sinensis to fruits for oviposition. Analysis of volatiles from different litchi tissues by HS-SPME-GC-MS revealed 31 similar volatiles, some of which may be important in the oviposition preference choices of C. sinensis on litchi fruit.

The Asian citrus psyllid Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the most widespread and devastating pest species in citrus orchards and is the natural vector of the phloem-limited bacterium that causes Huanglongbing (HLB) disease. Thus, reducing the population of D. citri is an important means to prevent the spread of HLB disease. Due to the long-term use of chemical control, biological control has become the most promising strategy. In this study, a novel highly pathogenic fungal strain was isolated from naturally infected cadavers of adult D. citri. The species was identified as Aspergillus fijiensis using morphological identification and phylogenetic analysis and assigned the strain name GDIZM-1. Tests to detect aflatoxin B₁ demonstrated that A. fijiensis GDIZM-1 is a non-aflatoxin B₁ producer. The pathogenicity of the strain against D. citri was determined under laboratory and greenhouse conditions. The results of the laboratory study indicated that nymphs from the 1st to 5th instar and adults of D. citri were infected by A. fijiensis GDIZM-1. The mortality of nymphs and adults of D. citri caused by infection with A. fijiensis increased with the concentration of the conidial suspension and exposure time, and the median lethal concentration (LC₅₀) and median lethal time (LT₅₀) values gradually decreased. The mortality of D. citri for all instars was higher than 70%, with high pathogenicity at the 7th day post treatment with 1 × 10⁸ conidia/mL. The results of the greenhouse pathogenicity tests showed that the survival of D. citri adults was 3.33% on the 14th day post-treatment with 1 × 10⁸ conidia/mL, which was significantly lower than that after treatment with the Metarhizium anisopliae GDIZMMa-3 strain and sterile water. The results of the present study revealed that the isolate of A. fijiensis GDIZM-1 was effective against D. citri and it provides a basis for the development of a new microbial pesticide against D. citri after validation of these results in the field.

The Chinese citrus fly, Bactrocera minax (Enderlein) (Diptera: Tephritidae), is the most destructive pest in many citrus orchards of south central China. Methyl eugenol and cuelure, 2 potent male lures that are effective for capturing related species, are believed not to attract this species. Limited knowledge is available about the effectiveness of attractant traps for this pest. A field trial was carried out to determine the efficacy of 8 attractant traps to B. minax. The study was conducted during the adult occurrence season in an orchard of navel orange, Citrus sinensis (L.) Osbeck (Rutaceae), in Zhijiang County, Hunan Province, China, in 2016. To link the efficacy of these attractant traps with the pest population, fruit infestations in the orchard also were investigated. As expected, this study confirmed that methyl eugenol and cuelure were not attractive to B. minax. Green-colored sticky spheres trapped significantly more flies and males than methyl eugenol and cuelure-baited traps. On ave... Resumen La mosca china de los cítricos, Bactrocera minax (Enderlein) (Diptera: Tephritidae), es la plaga más destructiva en muchos huertos de cítricos del sur de China central. Se cree que el metil eugenol y la cuelure, dos señuelos potentes para los machos son efectivos para capturar especies relacionadas,pero se cree que no atraen a esta especie. Existe conocimiento limitado sobre la efectividad de las trampas atrayentes para esta plaga. Se realizó una prueba de campo para determinar la eficacia de 8 trampas atrayentes para B. minax. El estudio se realizó durante la temporada cuando los adultos estran presentes en un huerto de naranja navel, Citrus sinensis (L.) Osbeck (Rutaceae), en el condado de Zhijiang, Provincia de Hunan, China, en el 2016. Para vincular la eficacia de estas trampas atrayentes con la población de la plaga, también se investigaron las infestaciones del fruto en el huerto. Como se esperaba, este estudio confirmó que el metil eugenol y la cuelure no fueron atractivos para B. minax. La...

The Empoasca onukii (Hemiptera: Cicadellidae) female lays its eggs inside the epidermis of the tea plant shoots. This has led to speculation that shoot harvesting could represent a method of egg removal. To verify the validity of this hypothesis, we sought to determine which part of the shoot was used for the oviposition and how the value of the harvested shoot affects the cost of the egg removal. In this study, four tea cultivars were chosen to examine the preferences for the site of oviposition. In addition, a mathematical model was used to describe the correlation between the economic value of the selected shoot and eggs laid within the shoot. Our study revealed that the pest preferred the 3rd and 4th leaf order intervals of the shoot as the oviposition sites, and the oviposition preferences was dependent on the leaf order interval class across all tea cultivars. In addition, a significant negative exponential relationship was found between the economic value of the selected shoot and the percentage of the eggs laid within the shoot, indicating that egg removal through shoot harvesting was limited. The findings of this study could be used to better understand the role of shoot harvesting in egg removal and would provide new insights into the understanding of the incidence of this pest.