Effect of sublethal doses of abamectin on demographic traits of tomato leafminer Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae)

Abstract

The tomato leafminer, Tuta absoluta is a serious pest of tomato crops worldwide. In this study the effect of sublethal concentrations of abamectin (at 10 and 30% lethal concentrations, LC 10 and LC 30 ) was investigated on developmental and reproduction parameters of the tomato leafminer Tuta absoluta. Lethal concentrations were estimated by leaf dip bioassay on the fourth instar larvae of the T. absoluta that, LC 50 , LC 30 and LC 10 were 0.23, 0.15 and 0.12 mg · l -1 , respectively. The sublethal concentrations led to significant decreases in adult emergence, the percentage of pupation of the parent generation, fecundity and adult longevity compared to the control. Sublethal concentrations significantly decreased the net reproductive rate (R 0 ), intrinsic rate of increase (r), finite rate of increase (λ), and gross reproduction rate (GRR). There was a significant decrease in the time to egg developmental and doubling time (DT) of T. absoluta. However, sublethal concentrations of abamectin had no significant effects on the percentage of pupation, larva, prepupa and pupa developmental periods, hatchability and sex ratio of offspring. The results of this study indicated that sublethal concentrations of abamectin could influence some biological parameters of T. absoluta. The results could also be helpful for making better management decisions for controlling the tomato leafminer.

Sublethal Effects of Emamectin Benzoate on Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…LC 10 , LC 20 and LC 30 abamectin severely affected the fecundity of predatory mite, Phytoseius plumifer (Canestrini and Fanzago) and Scolothrips longicornis Priesner [39,40]. Similar, the fecundity of T. absoluta treated with LC 10 and LC 30 abamectin was significantly lower than the control [41]. Although sublethal concentrations (LC 10 and LC 20 ) of EMB did not influence FAW fecundity in our study, both concentrations could cause a significant reduction in viable eggs laid by female.…”

“…Due to its burst release and rapid degradation of EMB under natural sun light, EMB shows a short half-lives (0.37-0.64 days) in the crops [32,34]. However, the residues of EMB might lead to sublethal effects over space and time, including influencing the developmental time, weight, fecundity, longevity and physiological parameters without directly causing death [16,[22][23][24][25]35]. FAW is a highly destructive polyphagous invasive pest that causes substantial losses to agricultural production.…”

“…Low-lethal concentrations (LC 10 , LC 20 and LC 30 ) of abamectin significantly reduced the longevity of predatory thrips S. longicornis [40]. The longevity of T. absoluta female and male exposed to the LC 10 and LC 30 treatment of abamectin was significant lower than the control [41]. Similarly, LC 50 value of abamectin caused significant reduction in female longevity of Cryptolaemus montrouzieri Mulsant [44].…”

“…), and reduce their population parameters [22]. LC 30 of EMB decrease the pupal weight, longevity and fecundity of Tuta absoluta (Meyrick) [23], and inhibit the body weight of Lymantria dispar (L.) [24]. EMB is mainly stomach toxicity, which has a specific contact-killing effect.…”

Efectos subletales y costos de resistencia a abamectina en palomilla dorso de diamante (Plutella xylostella) (Lepidoptera: Plutellidae)

“…En esta investigación se confirma dicha capacidad al obtener un factor de resistencia de 33,39 veces al realizar una presión de selección de abamectina en diez generaciones. Zhou et al (2010) reportan un incremento en la susceptibilidad de 5,80 veces para este mismo insecticida bajo una selección de resistencia en 11 generaciones de P. xylostella. Por su parte Wang y Wu (2014) obtuvieron un factor de resistencia de 11,50 veces para una línea recolectada en campo y mantenida bajo presión de selección durante 21 generaciones.…”