Landscape-scale intensification of individual crops and pesticide use that is associated with this intensification is an emerging, environmental problem that is expected to have unequal effects on pests with different lifecycles, host ranges, and dispersal abilities. We investigate if intensification of a single crop in an agroecosystem has a direct effect on insecticide resistance in a special...

J. Econ. Entomol.91 (1): 7-20 (1998) ABSTRACT The relationship between Irish potato tuber yield, So/anum tuberosum L., and defoliation by the Colorado potato beetle, Leptinotarsa decem/ineata (Say), was investigated and the use of regression and mean separation analyses as a basis for developing economic injury levels were compared. The type of statistical analysis used to describe this relatio...

A male-produced aggregation pheromone was identified for the Colorado potato beetle Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae). While male beetles produced only minor amounts of the pheromone, its production could be enhanced by topical application of juvenile hormone III (JH III) (eightfold), by antennectomy (40-fold) or by the combined treatment of JH III and antennectomy (al...

Variation in sperm precedence was examined in the Colorado potato beetle, Leptinotarsa decemlineata Say, using neutral allozyme markers. Two temporal components were studied: (1) pairing duration and (2) time since initial pairing. We used two pairing protocols that differed in the timemales and femaleswere allowed tomate for Þrst and secondpairings.Whenpairingswere limited to 8 h each for the ...

Plant surfaces showing hierarchical structuring are frequently found in plant organs such as leaves, petals, fruits and stems. In our study we focus on the level of cell shape and on the level of superimposed microstructuring, leading to hierarchical surfaces if both levels are present. While it has been shown that epicuticular wax crystals and cuticular folds strongly reduce insect attachment,...

the aim of the present work was to purify cysteine protease inhibitors from rapeseed (brassica napus l.), with potential activity on digestive protease of colorado potato beetle (cpb), leptinotarsa decemlineata (say). ammonium sulfate precipitated proteinaceous fractions; 30, 50, 70, and 100% showed 39.07, 57.03, 51.47, and 22.44% inhibition on the fourth instar larval gut general protease acti...

Information on the genetic structure of animal populations can allow inferences about mechanisms shaping their social organization, dispersal, and mating system. The mongooses (Herpestidae) include some of the best-studied mammalian systems in this respect, but much less is known about their closest relatives, the Malagasy carnivores (Eupleridae), even though some of them exhibit unusual associ...