History, evolution, and consequences of insecticide resistance

Effects of Bio-Rational Insecticides on Selected Biological Aspects of the Egyptian Cotton Leafworm Spodoptera Littoralis (Boisd.) (Lepidoptera: Noctuidae)

“…Due to appearance of high resistance to many chemical pesticides and resurgence of chemical pesticides (Forgash 1984;Georghiou 1986) more attentional should be paid to the use of bioinsecticides such as compounds based on bacteria, fungi, insect growth regulators and botanical pesticides (Rao et al 1990). These groups have different mode of action from conventional products (Asher 1993;Thompson et al 1999) and their properties may differ considerably from the conventional agents with which growers are familiar.…”

Effect of bio-rational insecticides on some biological aspects of the Egyptian cotton leafworm Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae)

“…Due to the appearance of high resistance to many chemical pesticides and resurgence of chemical pesticides (Forgash 1984;Georghiou 1986) there is growing interest in the use of bioinsecticides such as compounds based on bacteria, fungi, insect growth regulators and botanical pesticides (Rao et al 1990;Ahmad et al 2008;Mourad et al 2008). These groups have modes of action different from those of conventional products (Ascher 1993; Thompson et al 1999); also, their properties may differ considerably from the conventional chemicals with which growers are familiar.…”

Pesticide Mixtures

“…The assumptions presented above, in nearly all instances, are not realistic. For example, pesticide mixtures may, in fact, promote the expression of multiple resistance, which could extend across other chemical classes resulting in specific arthropod pest populations being very difficult to manage (Forgash 1984;Brattsten et al 1986;Ahmad 2004;Attique et al 2006). Furthermore, multiple evolutionary pathways may exist that eventually result in a pesticide-resistant arthropod pest population (Metcalf 1980;Georghiou 1983;Brattsten et al 1986;Ishaaya 1993).…”

“…It is possible that under these given circumstances, individuals simultaneously possessing resistance mechanisms to both pesticides will be extremely rare (Curtis 1985;Brattsten et al 1986;Mallet 1989;Roush 1993); 2) individuals in the arthropod pest population possess resistance genes (alleles) that are exclusively recessive and/or individuals that are doubly-resistant are very rare. Evolution of resistance will be instantaneous if any survivors possess doubly-resistant genes or multiple resistance mechanisms (Curtis 1985;Comins 1986;Tabashnik 1989;Mallet 1989); 3) some individuals in the arthropod pest population are not treated or exposed to the pesticide mixture primarily due to the presence of refugia (Georghiou and Taylor 1977b;Brattsten et al 1986;Tabashnik 1989;Tabashnik 1990), or there is immigration of and mating with susceptible individuals, which reduces the frequency or proportion of resistant individuals (or resistant genes) in the arthropod pest population (Comins 1977;Georghiou and Taylor 1977b;Tabashnik and Croft 1982;Comins 1986;Georghiou and Taylor 1986;Mallet 1989;Jensen 2000;Stenersen 2004); 4) the pesticides mixed together have equal persistence so that any individuals in the arthropod pest population are not exposed to just one pesticide for an extended length of time (Forgash 1984;Curtis 1985;Tabashnik 1989;Tabashnik 1990;Roush 1993); and 5) resistance mechanisms to each pesticide are present at such low frequencies that they may not occur together in any individuals in an arthropod pest population (Yu 2008). The assumptions presented above, in nearly all instances, are not realistic.…”

“…The carbamate insecticides methiocarb, pirimicarb and oxamyl, and even the fungicide propamocarb have been shown to synergize the efficacy (based on percent mortality) of the pyrethroid-based insecticide acrinathrin against the western flower thrips (Bielza et al 2007;Bielza et al 2009). However, continued use of these types of pesticide mixtures may result in resistance to both modes of activity by arthropod pest populations, especially those that have the capacity of developing multiple resistance, which refers to an arthropod pest population resistant to pesticides with discrete modes of action or across chemical classes affiliated with the expression of different resistance mechanisms (Forgash 1984;Comins 1986;Georghiou 1986;Brattsten et al 1986;Metcalf 1989;Attique et al 2006;Ahmad et al 2008). As with applications of individual pesticides, it is important to only mix together pesticides with different modes of action or those that affect different biochemical processes in order to mitigate resistance developing in arthropod pest populations (Cranham and Helle 1985;Cloyd 2009).…”