Antifeedant effect, biological efficacy and high affinity binding of imidacloprid to acetylcholine receptors inMyzus persicaeandMyzus nicotianae

Abstract

: It is known from laboratory studies that tobacco-associated forms of Myzus persicae (Sulzer) and the closely related tobacco aphid Myzus nicotianae (Blackman) are often somewhat less susceptible to imidacloprid than nontobacco strains of M. persicae. Choice tests (Ñoating leaf technique) showed that tobacco aphids were also less susceptible to the antifeedant potential of imidacloprid in contact bioassays. Synergists like piperonyl butoxide or DEF did not enhance the susceptibility of tobacco-associated morphs of Myzus ssp. to imidacloprid, thus providing evidence that neither oxidative detoxication nor hydrolytic metabolization took place. However, in an attempt to study the inÑuence of endosymbiotic bacteria on the efficacy of imidacloprid, we allowed small populations of tobacco aphids to feed on diets containing the antibiotic chlortetracycline prior to imidacloprid treatment. While the e †ectiveness of imidacloprid, i.e. lower values, could be improved in all strains, including the susceptible LC 50 reference strain, there was no change in overall tolerance factors. In order to investigate any possible alteration of the target site, the affinity of imidacloprid and nicotine to nicotinic acetylcholine receptors in whole-aphid homogenates was measured. All strains (and clones) showed the same high-affinity binding sites and no detectable di †erence.Studies using the FAO dip method revealed that the lower susceptibility of M. nicotianae is not restricted to chloronicotinyls like imidacloprid or acetamiprid, because other insecticides with di †erent modes of action such as pymetrozine and Ðpronil were also a †ected in laboratory studies. It is considered that the observed tolerance to chloronicotinyls in certain strains of Myzus ssp. is a natural variation in response, probably not coupled with any known mechanism of resistance in this species complex.1998 SCI ( Pestic. Sci., 53, 133È140 (1998)

Adsorption and Leaching Potential of Imidacloprid Pesticide through Alluvial Soil

“…It is most commonly used on rice, cereal, maize, sunflowers, potatoes and vegetables. It is applied as a seed and soil treatment, crop and structural treatment, and a topical flea control treatment on domestic pets [1][2][3][4][5]. It is also used for animal health applications to control parasites like fleas of dogs and cats [6].…”

Effect of Selected Insecticides on <I>Homalodisca coagulata</I> (Homoptera: Cicadellidae) and Transmission of Oleander Leaf Scorch in a Greenhouse Study

“…The knockdown effect of pyrethroids on insects are well known. Imidacloprid is widely used as a systemic insecticide to control piercing-sucking insects (Nauen et al 1998;1999), including sharpshooters in citrus orchards and vineyards Castle et al 2005;Byrne & Toscano 2006;Byrne & Toscano 2007). The contact effect of imidacloprid, causing high sharpshooter mortality within a short period of time, is described here for the first time.…”

Susceptibility of Asian citrus psyllid, Diaphorina citri (Hemiptera: Liviidae), to the insecticide afidopyropen: a new and potent modulator of insect transient receptor potential channels

“…Previous investigations have shown that continuous feeding for approximately 30 min on infected trees is required to successfully acquire the pathogen, and 5-7 h of feeding on trees is required to transmit the pathogen to healthy plants ( Grafton-Cardwell et al 2013). Therefore, the spread of HLB may be reduced by deterring the vector from feeding on citrus plants (Chiyaka et al 2012;Nakasuji et al 1975;Nauen 1995;Nauen et al 1998), which serve as hosts for both the pathogen and the vector. The present study indicated that afidopyropen acts as a feeding deterrent against D. citri.…”

“…Exposure to sublethal insecticide concentrations is known to cause physiological changes that reduce development and fecundity and lead to an overall fitness decline in certain insect species (Harnoto et al 1984;Luckey 1968;Omer and Leigh 1995;Stark and Banks 2003). In general, exposure of hemipteran species to sublethal insecticide concentrations reduces feeding, growth, survival, and reproduction (Kerns and Stewart 2000;Lee et al 1988;Nauen et al 1998). Alternatively, exposure to sublethal concentrations may increase fecundity by stimulating reproduction through hormoligosis, which increases fitness (Chen and Nakasuji 2004;.…”