Relative resistance of maize varieties against maize weevil, Sitophilus zeamais (Motschulsky), (Coleoptera: Curcolionidae)

Abstract

The maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), is one of the most damaging pests of stored cereals causing severe damage to stored grains. In current investigation, six open pollinated maize varieties viz. JALAL (white), AZAM (white), SADAF (yellow), ZARD LOCAL (yellow), KASHMIRI (yellow) and PAHARI (white) were screened out in the laboratory of Entomology Department, Faculty of Agriculture, Gomal University, Dera Ismail Khan, Pakistan for their relative susceptibility/resistance to maize weevil. The experiment was laid out following completely randomized design (CRD) with 5 replicates. Results revealed that minimum (23.8) days to adult emergence of maize weevil were recorded when it was reared on variety Azam; whereas; maximum (34.2) days were recorded on variety Sadaf. Total number of F1 adults emerged were maximum (91) in Azam while minimum (62) in variety Sadaf. Percent infestation of maize kernels was maximum (39.01%) in Azam while minimum (25.80%) was recorded in variety Sadaf. Percent weight loss was maximum in Azam i.e. 26.12% while minimum percent weight loss (16.88%) was recorded in Sadaf. Maximum longevity (68.4 days) of adult weevils was recorded on Azam while minimum (53.4 days) was recorded on variety Sadaf. All the tested varieties had no significant effect on the sex ratio of emerged weevils. High germination percentage was recorded in Sadaf (90%) whereas; low germination was found in Azam (57%). The grain hardness test indicated that yellow varieties including Sadaf, Zard local and Kashmiri had maximum hardness having 317, 302.33 and 296 N grain hardness, whereas; white varieties i.e. Pahari, Jalal and Azam had minimum values of grain hardness i.e. 264.33, 251.66 and 238.33 Newton. The present work has shown that Azam is the most susceptible variety and should not be stored for longer periods whereas; Sadaf is the resistant variety against maize weevil.

Mecanismos de resistencia de poblaciones de maíz originarias de México al ataque del picudo Sitophilus zeamais

“…Acheampong et al (2019) demostraron que la variedad de maíz 'Aseda' inhibió el ataque de S. zeamais con menor pérdida de peso, daño y alta germinación del grano; así como una alta mortalidad de adultos y retraso en el desarrollo, minimizando la merma de semillas cuando se almacenan durante tres meses. Los genotipos resistentes reducen la tasa de daño a los granos almacenados causados por escarabajos y palomillas, debido a la dureza del grano, pericarpio liso (impedimento de las mandíbulas para el agarre), así como la concentración alta de compuestos fenólicos (Mamoon-Ur-rashid et al, 2021). Además mantienen la germinación de los granos y la calidad, muy probablemente por alelos adaptativos como las líneas endogámicas retrocruzadas (BILs) y los locus de rasgos cuantitativos (QTLs) que continúan evolucionando para que los mecanismos de tolerancia y resistencia subsistan (Joshi et al, 2021).…”

“…El picudo del maíz Sitophilus zeamais (Motschulsky) es un insecto del orden Coleoptera: Curculionidae, y se considera una de las principales plagas pre y postcosecha, cuyo daño se detecta principalmente durante el almacenamiento (García-Lara y Bergvinson 2013; Mamoon- Ur-rashid et al, 2021) como un colonizador primario del grano de maíz (Trematerra et al, 2014), donde produce hasta un 60 % de pérdidas de peso y calidad dentro de los 3 a 6 primeros meses de almacenamiento en los países en desarrollo (Ileke et al, 2020). Su distribución es mundial, afecta principalmente a regiones tropicales, subtropicales húmedas y templadas (Hong et al, 2018).…”

Medicinal Plants as a Natural Greener Biocontrol Approach to “The Grain Destructor” Maize Weevil (Sitophilus zeamais) Motschulsky

“…Studies on pesticide resistance are crucial for developing practical pest management strategies as well as serving as models for the evolution of newly adaptive phenotypes and the physiological (and genetic) alterations that they cause [101][102][103]. When pesticide use is reduced, eliminated, or changed, the pleiotropic consequences that typically follow selection for pesticide resistance may disadvantage the resistant insects [101,[104][105][106][107]. In the absence, diminution, or modification of pesticide selection, this may cause a gradual decrease in the frequency of resistant individuals over time.…”

“…In the absence, diminution, or modification of pesticide selection, this may cause a gradual decrease in the frequency of resistant individuals over time. Only in the last scenario is there no common expectation of a physiological cost of resistance among the four fundamental molecular mechanisms of pesticide resistance (constitutive overproduction, constitutive underproduction, target alteration, and inducible change in gene regulation) [98,99,101,106]. Pesticide resistance-causing changes typically cause negative effects by obstructing the routes of their targets (or receptors) [99].…”

A study on the susceptibility of maize genotypes against the maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae)

“…Although pest infestations can happen in the field, the majority of damage happens during storage (Manu et al, 2018). The maize weevil, Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae), which is a significant pest of maize in the tropics and causes significant losses to many impoverished farmers who store grains on their farms for use as food and seeds, is primarily responsible for the damage (Rashid et al, 2021).…”