Spatial Demogenetic Model for Studying Phenomena Observed upon Introduction of the Ragweed Leaf Beetle in the South of Russia

Abstract

The introduction of the ragweed leaf beetle in the South of Russia in 1978-1989 was accompanied by a number of spectacular phenomena that determined the general success of the ragweed control and further dispersal and acclimatization of the beetles: (i) formation of solitary population waves (SPW), characterized by an extremely high density of the phytophage population at the narrow band of the front of a moving wave defoliating nearly all ragweed plants, and (ii) rapid, within 5-6 generations, development of flight in the leaf beetle species that in its homeland lost the ability to fly. We present here a demogenetic model capable of reproducing both these phenomena, assuming that the flight ability of a phytophage population is governed by a single diallelic locus with flight and flightless alleles that determine three genotypes of the ragweed leaf beetle. Simulation results agree well with the practical recommendation of retaining a high density of common ragweed in the release area in order to provide the necessary conditions for the initial increase of the leaf beetle population and the formation of the wave. The model confirms the earlier hypothesis that the SPW is the key factor that determines efficiency of weed biocontrol program. We demonstrate also that the formation of the wave has crucially accelerated the development of the beetles' ability to fly.

Modelling Effects of Rapid Evolution on Persistence and Stability in Structured Predator-Prey Systems

“…Food-web models including rapid evolution are now gaining more and more popularity in the ecological literature in the recognition of the fact the rapid evolution can dramatically affect population dynamics [21,22,13,45,16,44]. In this paper, we have analytically investigated the recent eco-evolutionary predator-prey model proposed by Morozov et al in [34], which is given by equations (1.1)-(1.2).…”

Modeling Study of Factors Determining Efficacy of Biological Control of Adventive Weeds

“…Model ( 1)-( 4) is a modification of the system presented previously in [15,16], which did not consider effect of the cultivated plant but accounted for the genetic structure of the phytophagous population. Since apart from the weed there present also other plants in terrestrial ecosystems, inclusion of a cultivated plant in the model makes it more realistic and appropriate for solving applied problems of weed biocontrol.…”

“…The first mathematical model describing the SPW of the ragweed leaf beetle was suggested by Vechernin and Kovalev [14]. Later, Tyutyunov and coauthors [15,16] elaborated a more detailed demogenetical model capable of reconstructing the formation and movement of the phytophage SPW and explaining other phenomena observed after the introduction of the ragweed leaf beetle, including the rapid transformation of the genetic structure of the leaf beetle population caused by selection of traits enhancing the flight ability of the beetle, which had been evolutionarily lost in its homeland.…”

Factors of biologization of farming in the forest-steppe zone of Volga region

“…4) Biological plant protection. Biologization of plant protection is possible due to techniques directed to preserving natural entomophages and antagonists [31]; the introduction of phytophages against certain species of weeds [32] and the use of biological products for the destruction of pests and pathogens.…”