Advancements in Mass Rearing the Air Potato Beetle Lilioceris cheni

The air potato beetle, Lilioceris cheni Gressitt and Kimoto (Coleoptera:Chrysomelidae), is a successful biological control agent of the air potato vine, Dioscorea bulbifera L. (Dioscoreales: Dioscoreaceae), in the southern United States. Lilioceris cheni is currently being mass-reared by the Florida Department of Agriculture and Consumer Services Division of Plant Industry (FDACS-DPI) for biological control releases and research. The facility rears and releases over 50,000 adult beetles annually at approximately 1000 different locations. In addition to data on beetle production and distribution, studies on alternative larval and adult diets are described. Adults fed bulbils as the sole food source had reduced life spans compared with beetles given fresh air potato leaves. Adults survived without air potato leaves or bulbils for several days to two weeks depending on availability of leaves at emergence. Larvae did not survive on a modified artificial Colorado potato beetle diet containing fresh air potato vine leaves. Adults survived while consuming artificial diet but ceased oviposition. They, however, resumed egg laying less than one week after being returned to a diet of fresh air potato vine leaves.

Experimental studies of a machine for collecting the Colorado potato beetle

ional Academy of Sciences of Belarus, Minsk, the Republic of Belarus The substantiation of the design and technological scheme of the machine for the mechanical collection of the Colorado potato beetle in the production of environmentally friendly potato is carried out. The parameters and modes of rotors with flexible-elastic blades and regulators of the amplitude of their oscillations, providing high-quality shaking and collection of Colorado potato beetle individuals from the tops with minimal damage, have been experimentally substantiated. A description of the laboratory installation, an experimental sample of a combined unit is presented, and a methodology for conducting experiments is described. Experimental studies were carried out in 2004-2008 in the experimental field of the Educational institution "Grodno State Agrarian University" (UO "GGAU") and in the fields of the Agricultural production cooperative (SEC) "Zanemansky" of the Mostovsky dis-trict of the Grodno region. It was found that in order to reduce the energy intensity of the process, the interaction of the rotor with the tops in its apical part, where the maximum con-centration of Colorado potato beetle individuals takes place, is expedient. The minimum amount of beetle on the tops and the absence of visible damage to it are achieved when the diameter of the nylon threads of the blade is 1.2-1.5 mm, and the rational position of the regulator from the rotor axis is 0.14-0.18 m according to the energy intensity condition. Under the condition of minimal energy consumption of the process and without visible damage to the leaves, the circumferential speed range of the rotor should be 3-4 m/s. A regression equation of the second degree is obtained, which determines the relationship of the residual number of beetle individuals on the tops after the passage of the machine with the circumferential speed of the rotor Voc, the position of the regulator on the radius of the rotor Rr and the cross section of the blade Sbl. The optimal values were determined by solving the equation: Voc = 3.7 m/s, Rr = 0.16 m, Sbl = 1800 mm2 .

Intraspecific Divergence of the Colorado Beetle Leptinotarsa decemlineataSay (Coleoptera, Chrysomelidae) on the Territory of the USSR and Russia

The article presents the results of more than 40 years of research on the intraspecific variability and divergent microevolution of the Colorado Potato Beetle (CPB) during its expansion in the USSR and Russia. In this part of the species secondary area, 9 of its allopatric forms were mapped at the level of races (ecotypes), including 2 new ecotypes - northern and Azerbaijani, were identified in the last 5 years. To indicate ecotypes in the CPB area, the methods of classical population phenetics are applied. Ecotypes of the pest were formed in various potato-growing agro-climatic zones and differ in the individuals occurrence frequency with 9 types (morphs) of the imago pronotum pattern. Long-term changes in the phenetic structure of individual pest ecotypes over a period of 30-40 years were revealed. This indicates the continuation of microevolutionary processes in the CPB within the realized area due to the instability of the ecological situation in the agroecosystems. Under these conditions, the main inducers of divergent processes in pest populations are the agricultural production factors - for example, the resistant potato varieties such as Peterburgskiy, Ryabinushka, Sudaryinya and others.

Virulence of Beauveria bassiana Strains Isolated from Cadavers of Colorado Potato Beetle, Leptinotarsa decemlineata

The Colorado potato beetle, Leptinotarsa decemlineata (Say), is a serious, widely distributed pest of potato and other crops. This pest is able to defoliate the host plant and cause severe yield loss. Moreover, the pest quickly becomes resistant to many chemical pesticides. Therefore, the development of novel biopesticides targeting this pest is urgently needed. The purpose of this study was to obtain new strains of the entomopathogenic fungus Beauveria bassiana and assess their efficacy against L. decemlineata adults under laboratory conditions. Twelve strains were isolated from cadavers of Colorado potato beetles collected in potato fields in the Czech Republic. Test beetles were treated by suspensions of conidia at the concentration of 1 × 107 spores per milliliter and their survival was recorded daily for three weeks. The results of the bioassays revealed that all new native strains were pathogenic to L. decemlineata adults and caused mortality up to 100% at the end of the trial period with an LT50 of about 7 days. These strains were more virulent than a reference strain GHA and some of them can be recommended for the development of a new mycoinsecticide against L. decemlineata. Our findings also highlight the importance of searching for perspective strains of entomopathogenic fungi among naturally infected hosts.

Low-Dose Insecticide Combinations for Colorado Potato Beetle Control

Colorado potato beetle (CPB) is the most notorious and problematic insect defoliator pest of potato. It is well known for its ability to develop resistance to chemical insecticides, so novel treatment methods must be developed. A possible solution is the application of newer groups of insecticides (biotechnical and biological insecticides) which are more selective and to which resistance has not yet been recorded. This work investigated the use of ecologically acceptable insecticide treatments: azadirachtin, spinosad and spinetoram, and their combinations against CPB larvae in laboratory and field conditions. Reduced dosing and combinational treatments were used to determine if effective protection against CPB could be achieved while also improving economic results. Our results from laboratory trials showed that combinations of low-dose azadirachtin (25%) and low-dose spinetoram (5%) are suitable for use in CPB integrated pest management. The results of the field trial showed that the use of 50% reduced dosage of spinosad and spinetoram resulted in high efficacy (89–99%) and can be recommended as a treatment method that provides effective control of CPB, improved economic results, and a positive environmental impact. Based on the advantages that these treatments offer compared to chemical insecticides, further work is recommended to determine if these combinational treatments used in other dosages or in combinations with some other ecologically acceptable insecticides can provide satisfactory control of CPB.

First Sprayable Double-Stranded RNA-Based Biopesticide Product Targets Proteasome Subunit Beta Type-5 in Colorado Potato Beetle (Leptinotarsa decemlineata)

Colorado potato beetle (CPB, Leptinotarsa decemlineata) is a major pest of potato and other solanaceous vegetables in the Northern Hemisphere. The insect feeds on leaves and can completely defoliate crops. Because of the repeated use of single insecticide classes without rotating active ingredients, many chemicals are no longer effective in controlling CPB. Ledprona is a sprayable double-stranded RNA biopesticide with a new mode of action that triggers the RNA interference pathway. Laboratory assays with second instar larvae fed Ledprona showed a dose–response where 25×10−6g/L of dsPSMB5 caused 90% mortality after 6days of initial exposure. We also showed that exposure to Ledprona for 6h caused larval mortality and decreased target messenger RNA (mRNA) expression. Decrease in PSMB5 protein levels was observed after 48h of larval exposure to Ledprona. Both PSMB5 mRNA and protein levels did not recover over time. Ledprona efficacy was demonstrated in a whole plant greenhouse trial and performed similarly to spinosad. Ledprona, currently pending registration at EPA, represents a new biopesticide class integrated pest management and insecticide resistance management programs directed against CPB.