scholarly journals Biological activity of saponins from alfalfa tops and roots against Colorado potato beetle larvae

2013 ◽  
Vol 54 (2) ◽  
pp. 35-45 ◽  
Author(s):  
Maryla Szczepaniak ◽  
Katarzyna Krystkowiak ◽  
Marian Jurzysta ◽  
Zbigniew Biały

The total saponins of alfalfa, <i>Medicago sativa</i> L., included in the diet of Colorado potato beetle larvae reduced their feeding, growth rate and survival. The biological activity of those compounds coming both from the roots and from the aerial parts is closely correlated with the dose. Larvae reared on leaves treated with a 0,5% dose virtually did not feed at all and died after 4-6 days. Lower saponin doses (0,01 and 0,001 %) reduced the insects' feeding to a lesser degree. However, they inhibited their growth, caused an extension of the larval stage and mortality at a level of 76,7- 100%. No major differences have been found in saponin activity depending on its localization in the plant.

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
F.S. Melnychuk ◽  
◽  
S.A. Alekseeva ◽  
O.V. Hordiienko ◽  
L.M. Melnychuk ◽  
...  

The article summarizes the results of determining the effectiveness of insecticides against the Colorado potato beetle (Leptinotarsa decemlineata Say) and aphids (Aphididae) with various methods of their application. Tests of a wide range of drugs with different active substances have provided high rates of stored yield in the system of potatoes’ protection. The investigated preptns showed a high level of protection against damage of plants by the Colorado potato beetle, when processing potato tubers. So, the effectiveness of the Prestige insecticides, 290 FS, Emesto Quantum 273,5 FS and Celest Top 312,5 FS, in the phase of active growth of the culture was 91,2-97,6%, and the duration of the protective effect was much longer than in Cruiser 350 FS, l.s.c, where the death rate was 86,1%. The predominant method of insecticidal treatments is the spraying of the aerial parts of plants during the growing season, as a rule, during the period of mass revival and development of Colorado potato beetle larvae. The greatest efficacy of insecticides on day 3 was noted on the options with the introduction of Confidor, 20% w.s.c., Calypso, 48% s.c. and Enzhio, 24,7% s.c., respectively 99,5%, 99,2% and 99,3%. The largest decrease in the number and population of potato plant aphids was noted with the use of the sample Enzhio, 24,7% s.c. at the recommended consumption rate – 98,2%. Along with this, other methods of insecticides’ applications are being developed and improved, in particular, the introduction of preps with drip irrigation. The effectiveness of the insecticides Enzhio, 24,7% s.c., Confidor, 20% w.s.c., was on par with Calypso, 48% s.c. The lowest protection observed in the areas of Actara’s, 24% c.p. application. In a field assessment of the insecticide’ use against aphids on a drip irrigation, it was noted that, with the usage of the Enzhio, 24,7% s.c., the efficiency was 99,4%. The use of other insecticides also contributed to a decrease in the population of potato plants by insect-pests and provided high protection at the level of 93,1-95,4%. Accordingly, the yield of potato tubers with the application of Enzhio, 24.7% s.c. was maximum and amounted to 29,7 t/ha.


1939 ◽  
Vol 17d (4) ◽  
pp. 103-107 ◽  
Author(s):  
M. I. Timonin

Beauveria Bassiana (Bals.) Vuill. isolated from infected Colorado potato beetle larvae is shown to be a pathogen to this host. The experiments indicated that some of the infected larvae may pass through the larval stage, but owing to further mycelial growth finally succumbed in the pupal stage. The fungus does not attack the eggs, but infected young larvae were found dying on the fourth day after hatching, when the eggs had been dusted with B. Bassiana spores. The mycelial growth on the infected larvae is more rapid in the soil than above ground.


Genetics ◽  
2001 ◽  
Vol 158 (2) ◽  
pp. 695-700 ◽  
Author(s):  
David J Hawthorne

Abstract A genetic linkage map was constructed from an intraspecific cross of the Colorado potato beetle, Leptinotarsa decemlineata. This is an initial step toward mapping the loci that underlie important phenotypes associated with insect adaptation to an agroecosystem. The map was made with 172 AFLP and 10 anonymous codominant markers segregating among 74 backcross (BC1) individuals. Markers were mapped to 18 linkage groups and a subset of the markers with a mean intermarker distance of 11.1 cM is presented. A pyrethroid-resistance candidate gene, LdVssc1, was placed onto the map as well. The sex chromosome was identified by exploiting the XO nature of sex determination in this species using patterns of variation at LdVssc1 and the codominant markers.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1464
Author(s):  
Maja Čačija ◽  
Renata Bažok ◽  
Majda Kolenc ◽  
Tena Bujas ◽  
Zrinka Drmić ◽  
...  

Colorado potato beetle (CPB) is an economic pest of potato that has developed resistance to all classes of chemical insecticides, thus requiring alternative control measures. As a potential solution, entomopathogenic nematodes (EPNs) have proven effective in suppressing this pest, but their efficacy against overwintering generations of CPB in Croatia has not been sufficiently researched. The aim of this two-year (2018–2019) field study was to determine the efficacy of Steinernema feltiae and Steinernema carpocapsae applied to overwintering CPB adults. EPNs were applied at three doses (7.5 mil./10 m2, 5.0 mil./10 m2 (the recommended dose) and 2.5 mil./10 m2) by watering the soil where the adults were overwintering. The first-year results were satisfactory for both EPNs: the efficacy of S. feltiae ranged from 79.03% to 100.00%, while the efficacy of S. carpocapsae ranged from 77.32% to 96.22%. In the second year, the highest efficacy (69.57%) was obtained using the recommended dose of S. feltiae. Although the results are not consistent across the two years of our study and suggest further research, they indicate that EPNs have great potential in controlling overwintering CPB generations to reduce first generation abundance and damage, and also to prevent the spread of new generations to surrounding potato growing areas.


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