scholarly journals ContacToxicity of Six Plant Extracts to Different Larval Stages of Colorado Potato Beetle (Leptinotarsa decemlineata SAY (Col: Chrysomelidae))

2017 ◽  
pp. 309-3316
Author(s):  
Mustafa Alkan ◽  
Ayhan Gökçe ◽  
Kenan Kara
1992 ◽  
Vol 124 (6) ◽  
pp. 945-949 ◽  
Author(s):  
Yvan Pelletier ◽  
Catherine L. Clark

AbstractHaemolymph from Colorado potato beetles at larval, pupal, and adult stages was analyzed for pH, osmolality, and concentrations of magnesium, calcium, potassium, sodium, chloride, phosphate, and citrate. Differences in the concentrations of some ions observed between stages were used to formulate physiological saline solutions for the adult and larval stages.


2010 ◽  
Vol 88 (5) ◽  
pp. 468-478
Author(s):  
G. Boiteau ◽  
P. C. McCarthy

It has been suggested that the stripes on the elytra of the adult Colorado potato beetle ( Leptinotarsa decemlineata (Say, 1824); Coleoptera: Chrysomelidae) and the red colouration of the larvae are aposematic characters warning predators of their distastefulness as prey. The role of stripes and red colour in determining the avoidance behaviour of the American Toad ( Bufo americanus Holbrook, 1836 = Anaxyrus americanus (Holbrook, 1836); Anura: Bufonidae) for the Colorado potato beetle was investigated in a series of laboratory tests. The behaviour of toads exposed to wild Colorado potato beetles was compared with that of toads exposed to genetic mutant Colorado potato beetles without elytral stripes. Tests confirmed the distastefulness of adult and larval stages and demonstrated the development of prey avoidance (cessation of feeding in spite of hunger) combined or not to behavioural displays where the toad plants down, crouches, and turns away or shows wincing, prey dropping, and mouth gaping after snapping at the beetle. However, toads showed the same response to mutant adult beetles without stripes and to mutant larval beetles without the red colour as to wild adult beetles with stripes and to wild red larvae. Results indicate that the stripes and the red colouration of the Colorado potato beetle do not constitute aposematic characters for the toad.


1990 ◽  
Vol 122 (6) ◽  
pp. 1141-1147 ◽  
Author(s):  
Yvan Pelletier

AbstractSolanum berthaultii Hawkes bears trichomes reportedly providing resistance to insects. Results indicated that the density of types A and B trichomes was linearly related to the inverse of the leaflet area. The number of trichomes on the adaxial and on the abaxial surface of terminal leaflets was not affected by two levels of water stress or by growing conditions in the greenhouse or the field. The leaflets of the water-stressed plants were generally smaller and, consequently, the density of trichomes higher.The survival of first-instar Colorado potato beetle larvae was similar on S. berthaultii grown under varying drought conditions and on leaves from field-grown plants bearing different densities of trichomes.


Sign in / Sign up

Export Citation Format

Share Document