Effect of Planting Date and Plant Spacing on Field Colonization by Colorado Potato Beetles, Leptinotarsa decemlineata (Say), in New Brunswick

1986 ◽  
Vol 15 (2) ◽  
pp. 311-315 ◽  
Author(s):  
Gilles Boiteau
Keyword(s):  
New Brunswick ◽  
Leptinotarsa Decemlineata ◽  
Planting Date ◽  
Plant Spacing ◽  
Leptinotarsa Decemlineata Say

COLD TOLERANCE IN THE COLORADO POTATO BEETLE, LEPTINOTARSA DECEMLINEATA (SAY) (COLEOPTERA: CHRYSOMELIDAE)

1996 ◽  
Vol 128 (6) ◽  
pp. 1087-1099 ◽  
Author(s):  
Gilles Boiteau ◽  
Warren Coleman
Keyword(s):  
Low Temperature ◽  
New Brunswick ◽  
Cold Tolerance ◽  
Seasonal Change ◽  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Gut Content ◽  
Potato Beetle ◽  
Leptinotarsa Decemlineata Say ◽  
Burrowing Behaviour

AbstractThe seasonal change in the level of cold tolerance in a field population of Colorado potato beetle, Leptinotarsa decemlineata (Say), is described for a northern location. Survival of overwintering adult beetles is highest from September through January. After that it falls to a lower level that is maintained until beetle emergence in May or June. The seasonal change in the level of cold tolerance is parallel to the change in the intensity of diapause but not to the change in the low temperature exotherm. The value of the low temperature exotherm is variable but averages −8.8°C for active beetles on plants and −11.7°C for soil-collected overwintering beetles in their deep diapause phase. Experimental results suggest that reduction of the gut content and increase in the amount of body fat in diapausing beetles is sufficient to lower the low temperature exotherm by a few degrees. The diapausing state itself, without cold acclimation, is sufficient to increase cold tolerance. However, results suggest that it is not the level of cold tolerance of the Colorado potato beetle provided by the diapausing process that has allowed this species to extend its range northward into New Brunswick but its accompanying burrowing behaviour.

TIMING OF INSECTICIDE APPLICATIONS FOR THE CONTROL OF THE COLORADO POTATO BEETLE, LEPTINOTARSA DECEMLINEATA (SAY), (COLEOPTERA: CHRYSOMELIDAE), ON POTATOES IN NEW BRUNSWICK

1988 ◽  
Vol 120 (6) ◽  
pp. 587-591 ◽  
Author(s):  
G. Boiteau
Keyword(s):  
New Brunswick ◽  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Russet Burbank ◽  
Optimal Time ◽  
Larval Abundance ◽  
Potato Beetle ◽  
Leptinotarsa Decemlineata Say ◽  
Spray Regimes ◽  
Insecticide Spray

AbstractDifferent insecticide spray regimes were tested in 1984, 1985, and 1986 to determine the optimal time to control the Colorado potato beetle, Leptinotarsa decemlineata (Say), on Russet Burbank potatoes in New Brunswick. Insecticides applied in mid-July at the peak of larval abundance when plants were entering into bloom had the greatest efficacy in controlling beetles and protecting the yield. A single insecticide application at 50% bloom was 12–17% and 82–95% more effective than one application at bloom and full growth, respectively.

scholarly journals Biochemical characterisation of α-glucosidase and β-glucosidase in the alimentary canal of larval Leptinotarsa decemlineata SAY, 1824 (Coleoptera: Chrysomelidae)

2014 ◽  
Vol 83 (4) ◽  
pp. 281-294 ◽  
Author(s):  
Majid Kazzazi ◽  
Fahimeh Dehghanikhah ◽  
Hossein Madadi ◽  
Vahid Hossseininaveh
Keyword(s):  
Incubation Time ◽  
Leptinotarsa Decemlineata ◽  
Digestive Enzymes ◽  
Specific Activity ◽  
Inhibitory Effect ◽  
Maximum Activity ◽  
Pest Population ◽  
Biochemical Characterisation ◽  
Leptinotarsa Decemlineata Say ◽  
Environmentally Safe

ABSTRACT Host plant resistance is an environmentally safe method used for reducing a pest population. Basically, when developing resistant cultivars one needs to study the biochemical characteristics of the digestive enzymes in the insect’s midgut. In this study, the activities of α- and β-glucosidase were determined from Leptinotarsa decemlineata midgut using p-nitrophenyl-α-Dglucopyranoside and p-nitrophenyl-β-D-glucopyranoside as substrates respectively. The results showed that the specific activity of α- and β-glucosidase from 4th instar larvae midguts of L. decemlineata were 5.14 and 5.48 Umg-1 protein respectively. The activity of α-glucosidase was optimal at pH 4, whereas the maximum activity of β-glucosidase in the midgut of L. decemlineata occurred at pH 4-5.5. Both enzymes were stable at pH 3-8 over an incubation time of 8 hours. The respective activities of α- and β-glucosidase were at their highest at 45 °C and 50 °C, but they were not stable at 50 °C during an incubation time of 8 days. Furthermore, our data showed that MgCl2, Tris and urea have a moderate but SDS a severe inhibitory effect on enzyme activity. Biochemical characterisation revealed one and three bands of α- and β-glucosidase activities in the midgut of L. decemlineata respectively.

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