INTERACTIONS AT THREE TROPHIC LEVELS: EDOVUM PUTTLERI GRISSELL (HYMENOPTERA: EULOPHIDAE), THE COLORADO POTATO BEETLE, AND INSECT-RESISTANT POTATOES

1989 ◽  
Vol 121 (10) ◽  
pp. 841-851 ◽  
Author(s):  
John R. Ruberson ◽  
Maurice J. Tauber ◽  
Catherine A. Tauber ◽  
Ward M. Tingey

AbstractResistant potato plants influenced the parasitoid Edovum puttleri Grissell directly, as well as indirectly through eggs of the parasitoid’s host, the Colorado potato beetle, Leptinotarsa decemlineata (Say). In the field, E. puttleri parasitized more egg masses on plants with no glandular trichomes or with glandular trichomes bearing only enclosed droplets of exudate than on plants with two types of glandular trichomes (one with exposed droplets and the other bearing enclosed droplets). Trichomes with exposed droplets entrapped numerous parasitoids. Although rearing L. decemlineata on resistant plants influenced many of the beetle’s life-history traits, it did not affect the suitability of their eggs for development and survival of preimaginal E. puttleri. However, eggs from L. decemlineata that were reared on resistant potato plants reduced the longevity of the parasitoids and also reduced the number of hosts (eggs) killed by parasitoids.

2005 ◽  
Vol 83 (2) ◽  
pp. 89-98 ◽  
Author(s):  
C. Noronha ◽  
G.M. Duke ◽  
M.S. Goettel

The phenology and damage potential of the Colorado potato beetle (Leptinotarsa decemlineata) were studied in the potato producing area in southern Alberta. Experimental plots were established at Lethbridge in 1998, 1999 and 2000, and at Vauxhall in 1998 and 1999. At each site, one plot was protected against the beetle by application of insecticides while the other was "unprotected." Natural potato beetle populations quickly colonized unprotected plots each year. Overwintered adults appeared in plots by mid June with mean densities reaching between 0.3 and 0.6 per plant. Eggs were laid on young plants with mean densities reaching two egg masses per plant by late June. Maximum larval densities reached 9.5 per plant for each of 1st, 2nd and 3rd instars and 14 per plant for 4th instars. Maximum density for newly emerged adults was 57 per plant in mid-July at the 2000 Lethbridge unprotected plot. Defoliation was very low at the beginning of the season but increased sharply when 3rd and 4th instar populations peaked and continued to rise as new adults emerged. Maximum defoliation occurred at the Lethbridge plot in 2000 with 100% defoliation by 10 August. Total yields in all unprotected plots ranged from 10 to 40% lower than in the protected plots. Mean density of overwintering adults within potato plots was 76 beetles m-2 with a maximum of 232 m-2. Mean overwintering mortality was 22% and mean depth of overwintering adults was 12 cm, with 63% of the beetles collected at depths ≤ 10 cm. Our results indicate that the phenology of the beetle is similar to that reported in areas where population buildups were rapid and devastating soon after insecticide resistant populations appeared. Consequently the beetle must be considered as a serious threat to potato production in southern Alberta.


Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1030
Author(s):  
Vladimír Půža ◽  
Jiří Nermuť ◽  
Jana Konopická ◽  
Oxana Skoková Habuštová

Colorado potato beetle Leptinotarsa decemlineata is among the most destructive pests of potatoes quickly developing resistance to traditional insecticides. In the present study, we tested the effect of various species and strains of entomopathogenic nematodes on CPB adults, and subsequently, the most effective nematodes were applied alone and in combination with entomopathogenic fungus B. bassiana in pots with potato plants and in the field and their effect on the number of emerging adults was evaluated. In the experimental infections, both the nematode invasion and pathogenicity were variable, and, in several strains, the mortality reached 100%. In pot experiments, soil application of nematodes S. carpocapsae 1343 and S. feltiae Jakub and fungus significantly decreased numbers of emerging CPB adults, while, after the application on leaves, only fungal treatment was effective. The field application of fungus B. bassiana significantly decreased the number of emerging CPB adults in comparison to control sites by ca. 30% while the effect of nematodes and the nematodes–fungus combination was not significant. In conclusion, we demonstrate the necessity of thorough bioassays to select the most effective nematode strains. Entomopathogenic nematodes have the potential to effectively decrease the emergence of CPB adults, but further research is needed to improve the effectiveness in the field.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 828F-828
Author(s):  
Benolt Lacasse ◽  
C. Laguë ◽  
S. Yelle ◽  
P.M. Roy ◽  
M. Khelifi

A front-mounted prototype designed to pneumatically remove Colorado potato beetles (CPB) from potato plants was tested in the field. Effects of different combinations of airflow velocities, nozzle widths, and travel speeds were investigated. Results showed that capture and dislodging of CPBs were better for adults and big larvae (L3 & L4). On the other hand, neither the airflow width and velocity nor the travel speed affected significantly the dislodging and the collection of small larvae. Field trials on the removal of larvae under the effect of different travel speeds showed that, the slower the prototype moved, the better was the collection of L3-L4 larvae. This study demonstrates the potential of pneumatic control of adult and L3-L4 CPBs.


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 820
Author(s):  
Pierre Bastarache ◽  
Gabriel Wajnberg ◽  
Pascal Dumas ◽  
Simi Chacko ◽  
Jacynthe Lacroix ◽  
...  

The Colorado potato beetle Leptinotarsa decemlineata is an insect pest that threatens potato crops globally. The primary method to control its damage on potato plants is the use of insecticides, including imidacloprid, chlorantraniliprole and spinosad. However, insecticide resistance has been frequently observed in Colorado potato beetles. The molecular targets and the basis of resistance to imidacloprid and chlorantraniliprole have both been previously quantified. This work was undertaken with the overarching goal of better characterizing the molecular changes associated with spinosad exposure in this insect pest. Next-generation sequencing was conducted to identify transcripts that were differentially expressed between Colorado potato beetles exposed to spinosad versus control insects. Results showed several transcripts that exhibit different expression levels between the two conditions, including ones coding for venom carboxylesterase-6, chitinase 10, juvenile hormone esterase and multidrug resistance-associated protein 4. In addition, several microRNAs, such as miR-12-3p and miR-750-3p, were also modulated in the investigated conditions. Overall, this work reveals a molecular footprint underlying spinosad response in Colorado potato beetles and provides novel leads that could be targeted as part of RNAi-based approaches to control this insect pest.


2016 ◽  
Vol 149 (2) ◽  
pp. 174-190 ◽  
Author(s):  
Gilles Boiteau ◽  
Pamela MacKinley

AbstractThis laboratory study confirmed that the strategy of adult terrestrial Colorado potato beetle (Leptinotarsa decemlineata (Say); Coleoptera Chrysomelidae) to survive the threat of drowning in water is based on avoidance of water crossings. It also showed that beetles at the surface of a body of water after failing to avoid it, long considered limited to passive floating and phoretic transport were in fact likely to rely on a complex fight or flee response. Beetles showed capacity to swim in a pattern similar to land foraging beetles. Beetles also tolerated submergence and walked underwater. These active behaviours should improve their probability of finding shore or refuge for longer survival. Results confirmed that Colorado potato beetles are likely to accumulate near water features in the potato agro-ecosystem landscape but suggest that successful crossings and colonisation of crops on the other side are more likely than previously expected. On a larger scale, new information provided by this study combined with our knowledge of dominant winds and currents should make it possible for future research to better predict the probability of surviving encounters with water and the orientation of invasive Colorado potato beetle colonisers dispersing at the surface of bodies of water.


2015 ◽  
Vol 24 (4) ◽  
pp. 729-740 ◽  
Author(s):  
Aleksandar Cingel ◽  
Jelena Savić ◽  
Branka Vinterhalter ◽  
Dragan Vinterhalter ◽  
Miroslav Kostić ◽  
...  

1997 ◽  
Vol 129 (4) ◽  
pp. 667-672 ◽  
Author(s):  
M.A. Edwards ◽  
W.D. Seabrook

AbstractTrials using four different sex combinations of Colorado potato beetle, Leptinotarsa decemlineata Say, demonstrated that male beetles move upwind towards females, whereas no attraction was seen between any of the other combinations. Attraction was not found to increase significantly after the female reached 10 days old. Visual stimuli appear to be unimportant from a distance of 50 cm. Orientation behaviour by the male beetle was observed as it walked upwind towards the female; no identifiable calling behaviour by the female was observed. The data indicate a sex pheromone is being produced by the female and is used by the male for mate location from a distance.


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