Comparative Study on Pseudaulacaspis Pentagona Resistance of Four Different Cultivars of Kiwifruit

Background:Kiwifruit is a common and popular fruit around the world. However, white peach scale (Pseudaulacaspis pentagona) [Targioni-Tozzetti], a scale insect with a wide range of hosts, seriously affects the yield and quality of kiwifruit. To investigate the differences in resistance of different kiwifruit cultivars to Pseudaulacaspis pentagona, cellular structure and gene expression assays were used to explain the mechanism. Results:In this study, based on the stability of the rate of injury fruit, we selected four cultivars from fifty kiwifruits for in-depth study, including “LC-04285”, “CF-3”, “DA-7B” and “Hayward”. By analyzing the differences in the anatomical structure of the canes of these cultivars, we found that the resistant cultivar "LC-04285" had thicker cuticle, denser epidermis and cortex. The real-time quantitative PCR data indicated that the expression levels of genes related to cuticle synthesis and formation of epidermis and cortex are also higher in “LC-04285”. Jasmonic acid (JA) is an important hormone involved in plant defense against many insect pests. In this study, we found that the expression levels of JA receptor COI1 were higher in “LC-04285”. However, the expression levels of AcJAZs, which played negative role in JA signaling, were higher in susceptible cultivar “Hayward”. Besides, the expression levels of AcICS, AcPAL4, AcPAL5, and AcNPRs, which were involved in salicylic acid (SA) synthesis and SA response, were also higher in “LC-04285”. Conclusions:Our results revealed the mechanism of kiwifruit resistance to P. pentagona at the molecular and cellular levels. This study provided useful guidance for breeding insect-resistant kiwifruit in future.

The conducting pheromone monitoring of the main pests of the orchard

Goal. Analysis of the latest methods for identifying pests of an orchard using pheromone monitoring and factors affecting its implementation. Methods. The studies were carried out in accordance with modern methodological approaches to pheromone monitoring of pests of fruit plantations. Results. The principles of pheromone monitoring in an orchard are given to identify harmful and quarantine organisms, which makes it possible to obtain information about the presence of pests in a certain area, determine their number, development dynamics, and, on the basis of the data obtained, plan and carry out appropriate phytosanitary measures. The main pests of the orchard of the Lepidoptera and Hemiptera classes have been identified, monitoring of which is carried out using pheromone traps. Methodological recommendations are given for conducting pheromone monitoring in fruit plantations to identify the eastern fruit moth (Grapholitha molesta Busck), Californian and mulberry scale insects (Pseudaulacaspis pentagona Targ.-Tozzetti, Quadraspidiotus perniciosus Comst), American white butterfly (Hyphantria cune). The advantages of the pheromone method over other monitoring methods are presented. The main factors that affect the catch of pests with pheromone traps are described. Conclusions. The information obtained with the help of pheromone traps is a component of effective programs — systems of integrated plant protection against pests, which combine the use of a complex of biological, chemical, agrotechnical measures, as well as fundamental for planning measures to prevent emergencies in a phytosanitary state. The informativeness and reliability of pheromone monitoring makes it possible to substantiate and develop instrumental monitoring technologies that reduce the number of chemical treatments by up to 30%, increase labor productivity by 75%, reduce costs by 70%, and increase the efficiency and reliability of accounting.

Data on biology and ecology of Pseudaulacaspis pentagona (Targioni Tozzetti) (Hemiptera: Diaspididae) on fruit trees in the Peloponnese

The study was conducted In Kalamata, Messinia, province of the Peloponnese, where infestations of Pseudauacaspis pentagona (Targioni Tozzetti) (Hemiptera: Diaspididae) were found on kiwi trees Actinidia deliciosa (Actinidiaceae), peach trees Prunus persica (Rosaceae) and mulberry trees Morus alba (Moraceae). Data on biology and ecology of the scale were recorded by samplings of infested branches of mulberry trees and by examining them in the laboratory, during the years 2016-2018. Pseudaulacaspis pentagona is an oviparous and amphigonic species. The fecundity of the scale fluctuated between 97 and 133 eggs per female. In the area of Kalamata it completed 3 generations per year and overwintered as mated pre-ovipositing female. The main natural enemies of P. pentagona recorded in the area of Kalamata are the coccinellid predators: Chilocorus bipustulatus (L.) and Rhyzobius lophanthae Blaisdell.

Evaluation of Entomopathogenic Bacteria Against Pseudaulacaspis pentagona (Targioni-Tozzetti) (Hemiptera: Diaspididae)

Pseudaulacaspis pentagona (Targioni-Tozzetti) (Hemiptera: Diaspidae) which has a wide host range, is an important pest causing losses in yield. The insecticides are used for control against this pest but insecticidal control is difficult as scales protect themselves very effectively with hard, waxy armor. Also, the negative effects of the chemicals used in the control against benefical insects and with the increasing awareness on environmental issues, alternative methods were sought. Therefore, this study was performed to develop an alternative and effective control method for this pest by using biocontrol bacteria Bacillus pumilus (TV-67C), Brevibacillus brevis (CP-1) and Bacillus megaterium (TV-91C) under controlled conditions. The death adult number of the pest was recorded and mortality rate was calculated. All of the tested bacterial strains showed mortality rates from 41.68% to 89.04% against the white peach scale under controlled conditions. Consequently, our results indicated that especially B. pumilus strain TV-67C and B. brevis strain CP-1 can be used as biocontrol agents of P. pentagona.

Mulberry (Morus nigra L., Moraceae) Hosting Scale Insects Crypticerya brasiliensis (Hempel, 1900) (Hemiptera: Monophlebidae) and Pseudaulacaspis pentagona (Targioni-Tozzetti, 1886) (Hemiptera: Diaspididae) in the Federal District, Brazil

The black mulberry tree (Morus nigra L. Moraceae), a perennial shrub, is one of the most abundant species in the urban afforestation of Brasília, Federal District, Brazil. This work records the first occurrence of Crypticerya brasiliensis (Hempel, 1900) (Hemiptera: Monophlebidae) and Pseudaulacaspis pentagona (Targioni-Tozzetti, 1886) (Hemiptera: Diaspididae) infesting M. nigra in the Federal District, Brazil. For this study, 20 specimens of M. nigra trees were inspected during September to October 2019, in two locations of the Federal District, Brazil, and the presence of scale insects were found on the trunks, stems, and leaves. The main damage caused by C. brasiliensis in the sampled trees were dry stems and branches along with yellow leaves, by the insects feeding mainly on the leaf veins. Pseudaulacapis pentagona was observed on the branches and stems of the plant isolated from the second sampling point. Infested branches were dry and leafless, with many scale insects, and some branches displayed small cracks. This is the first time M. nigra has been registered as a host plant of C. brasiliensis, as well as first occurrence of P. pentagona infesting M. nigra in the Federal District, Brazil.