Side Effects of Lambda Cyhalothrin and Thiamethoxam on Insect Pests and Natural Enemies Associated with Cotton

Abstract

T he genus Gossypium (Malvaceae) comprises of 40 species, among which four are commercially cultivated. One of the latter, the upland cotton, Gossypium hirsutum L., predominates with 95% of the total production area (FAO, 2015;Trapero et al., 2016). It is grown mainly to obtain fiber as a raw material for the textile industry (FAO, 2015). In 2019, 82,589,031 tons of cotton were produced from approximately 38,640,608 hectares (FAOSTAT, 2019) cultivated in more than 78 countries (Razaq et al., 2020). This represents 2.3% of all cultivated land in the world and indicates its economic and social importance (FAO, 2015).Until the end of the 19th century, there were few cases of pests associated with cotton (Razaq et al., 2020). However, the large number of hectares planted in different biogeographic regions, resulted in the insertion of a variety of arthropod species within the trophic networks of the agroecosystem, which expanded the diversity of these organisms, compared to what was originally found in center of origin (Naranjo, 2011). There are currently 1,300 species of phytophagous arthropods associated with cotton, Abstract | Cotton (Gossypium hirsutum) is cultivated mainly for the production of fiber for the textile industry and is attacked by different insect pests, therefore it is produced with frequent pesticide applications. Research was conducted to evaluate the effect of lambda cyhalothrin + thiamethoxam on the incidence of insect pests and its associated natural enemies. Results revealed that populations of B. tabaci were higher in plots treated with lambda cyhalothrin + thiamethoxam associated with low levels of parasitism. Further, A. gossypii were high and their parasitism low, in both treated and untreated plots. Individuals of T. palmi, B. thurberiella, H. virescens and A. vestitus were low in the treatments; while individuals of Dysdercus spp. were lower in the plots treated with the chemical insecticide. However, the predators, Coleomegilla maculata, Cycloneda sanguinea, Cheilomenes sexmaculata and Zelus sp., were inferior in the treated plots. Yield ranged from 1.2 to 1.4 tons. Thrips palmi is first reported feeding on cotton in Ecuador. The results showed high populations of B. tabaci in the chemical treatment, and its suppressive effect on the beneficial entomofauna. Future research should focus on evaluating the selective applications of some insecticides to control A. gossypii and Dysdercus spp. infestations that impact as little as possible on non-target organisms such as parasitoids and predators.

Can Capsicum spp. genotypes resist simultaneous damage by both Phytophthora capsici and Bemisia tabaci? Can natural enemies of Bemisia complement plant resistance?

“…In Ecuador, E. formosa has been the subject of biological control programs for tomato whitefly (Castillo et al, 2020). Encarsia nigricephala and E. pergandiella have been reported to attack B. tabaci nymphs on melon and cotton (Zambrano et al, 2021;Garcıá-Veĺez et al, 2023).…”

Effect of a synthetic insecticide and a botanical on pests, natural enemies and melon productivity

“…Populations of A. gossypii decreased from 81.3 to 10.6 individuals.leaf -1 at 336 hours post-application in plots sprayed with azadirachtin on a hydroponic cucumber (Saleem et al, 2019). In a field experiment conducted on cotton, A. gossypii populations failed to be controlled with L+T observing maximum levels of 63 individuals.leaf -1 (Zambrano et al, 2021). In the case of F. occidentalis, the number of thrips ranged from 10.3 to 24.6 individuals.leaf -1 with no significant differences between treatments (table 1).…”

Pyrethroid and Neonicotinoid Poisoning: A Good Prognosis

“…Insecticides are commonly used in India to save crop fields from being destroyed by unwanted insects and are hence readily available to a broad majority in rural India in an unregulated manner. Thiamethoxam and lambda-cyhalothrin are a newer insecticide combination of pyrethroid and neonicotinoid compounds commonly used now in India as commercial and home insecticides [ 1 ]. People are known to do unforeseen things while under the influence of alcohol.…”