Lethal and Sublethal Effects of Various Pesticides on Trichogramma achaeae (Hymenoptera: Trichogrammatidae)

Abstract

Little information is available regarding the lethal and sublethal effects of pesticides on Trichogramma achaeae (Nagaraja and Nagarkatti; Hymenoptera: Tricogrammatidae) during integrated management of Tuta absoluta (Meyrick; Lepidoptera: Gelechiidae), an important pest for tomato production. Twenty-two pesticides sprayed on Ephestia kuehniella (Zeller; Lepidoptera: Pyralidae) eggs were evaluated on the mortality of adult parasitoids upon contact with the hosts 24 h after the treatments and their sublethal effects on the parasitoids were assessed in laboratory conditions. Tests were carried out with fresh solutions at the recommended concentration. According to the International Organisation for Biological and Integrated Control (IOBC) standards, chlorpyrifos is harmful to the parasitoid; merthiocarb, methomyl, spinosad lambda-cyhalothrin, and acrinatrin are moderately harmful; and chlorantraniliprole, lufenuron, hexythiazox, cyromazine and Bacillus thuringiensis have no effect on the parasitoid. Sulfur is slightly harmful, and azoxystrobin is harmless. Chlorpyrifos was the most lethal among these pesticides and killed all females in less than 24 h. All other pesticides affected the biological parameters of T. achaeae to varying degrees. Regarding the lethal and sublethal effects, merthiocarb and spinosad killed all female offspring in less than 24 h; lambda-cyhalothrin and sulfur reduced the number of parasitized eggs; and acrinatrin, deltamethrin and azoxystrobin affected the emergence rate. After that, we can recommend the use of chlorantraniliprole and B. thuringiensis to control Lepidoptera, cyromazine to control Diptera, pirimicarb to control Homoptera, hexythiazox to control mites and azoxystrobin can be used as fungicide in an integrated pest management program with mass released of T. achaeae.

Effect of Sublethal Doses of Imidacloprid on the Biological Performance of Aphid Endoparasitoid Aphidius gifuensis (Hymenoptera: Aphidiidae) and Influence on Its Related Gene Expression

“…Therefore, the effects of sublethal doses of pesticides are important for improving IPM programs. In this work, we found that oral ingestion of sublethal doses of IMD, adversely affected parasitoid performance, including the survival rate, parasitic capacity, and longevity of female adults, which was consistent with the performance of the Aphidius colemani, Microplitis mediator, O. insidiosus, C. flavipes , and Trichogramma species exposed to pesticides (D'Avila et al, 2018; Fontes et al, 2018). In the M. mediator , exposure to flonicamid, pymetrozine, spinosad, and thiacloprid reduced its parasitization activity, percentage of parasitism and female longevity.…”

“…In the M. mediator , exposure to flonicamid, pymetrozine, spinosad, and thiacloprid reduced its parasitization activity, percentage of parasitism and female longevity. In addition, IMD impaired the longevity and parasitic capacity of Trichogramma species including Trichogramma achaeae, T. chilonis, T. platneri , and T. pretiosum (Khan and Ruberson, 2017; Fontes et al, 2018). The exposure to pesticides also adversely affected the biocontrol efficiency of pest predators (Moscardini et al, 2013; Nawaz et al, 2017).…”

Selectivity of deltamethrin doses on Palmistichus elaeisis (Hymenoptera: Eulophidae) parasitizing Tenebrio molitor (Coleoptera: Tenebrionidae)

“…The impact of deltamethrin on parasitism varies between species of parasitoids 25,26 , but, in general, this insecticide presented low selectivity and high sublethal potential since its low doses can reduce the fecundity and longevity of parasitoids 27 . Deltamethrin reduced the parasitism percentage of Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) in Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) eggs to 2.67% 28 and Eretmocerus mundus Mercet (Hymenoptera: Aphelinidae) on Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae) nymphs to 30% 29 .…”

Differential impacts of pesticides on Euschistus heros (Hem.: Pentatomidae) and its parasitoid Telenomus podisi (Hym.: Platygastridae)

“…Although biological control is essential for Integrated Pest Management (IPM) by maintaining pest populations below economic threshold levels, chemical control in many circumstances is necessary for effective management of stink bugs and other harmful organisms 22 present simultaneously in soybean crops. Therefore, the choice of chemicals for pest control in IPM programs should not be based only on the agronomic efficiency (e.g.…”