Chlorantraniliprole impact on survival and progeny quality of the pupa of the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae)

Abstract

The insecticide chlorantraniliprole is recommended for integrated pest management programmes of caterpillar (Lepidoptera) pest species. This insecticide is considered harmless to parasitoids, but its selectivity may vary with the species of natural enemy, few of which were subjected to testing. Furthermore, in addition to the active ingredient, formulation adjuvants may improve insecticide efficiency, but also its impact on nontargeted organisms. Here the chlorantraniliprole effect and its interaction with adjuvant on the survival and qualitative parameters of progeny of the nontarget parasitoid Palmistichus elaeisis (Delvare and LaSalle) (Hymenoptera: Eulophidae) were studied. The treatments used were: chrolantraniliprole (T1), chlorantraniliprole+surfactant (T2), and deionised water (T3, control). Pupae of Diaphania hyalinata Linnaeus (Lepidoptera: Crambidae) were subjected to these treatments for 24 hours and offered to the adult parasitoids. Chlorantraniliprole and chlorantraniliprole+surfactant did not elicit direct toxicity to female parasitoids. However, chlorantraniliprole and its combination with surfactant reduced the head capsule width of the female progeny. This insecticide alone also reduced emergence and the progeny metatibia length. Chlorantraniliprole did not induce mortality of P. elaeisis adults, but its negative impact on the emergence and progeny size of this parasitoid suggests an important sublethal effect to be considered.

Inert agricultural spray adjuvants may increase the adverse effects of selected insecticides on honey bees (Apis mellifera L.) under laboratory conditions

“…This suggests that the acute toxicity of the active ingredient also largely determines the effect enhancement by the adjuvant. Consequently, the toxicities of adjuvants are highly dependent not only on the particular target organism or PPP (class) combination but also on how they were administered (i.e., route of exposure) and what developmental stage they reach (i.e., egg, larva, adult) (Demkovich et al 2018;Lie et al 2019;de Sousa Pereira et al 2019). Whether the adjuvants examined in this study can have negative effects on honey bees after oral administration or under eld conditions must be answered in further experiments.…”

Compatibility of Bioinsecticides with Parasitoids for Enhanced Integrated Pest Management of Drosophila suzukii and Tuta absoluta

“…The 51.8% of host mortality found in the current study using the recommended label rate could be related to the widespread resistance of this pest to chlorantraniliprole across the Mediterranean region [6], including Italy where the pest colony used in this study was initiated. Although chlorantraniliprole is generally considered harmless to natural enemies [71,72], several studies also showed negative effects on the parasitoid's reproduction and offspring emergence [73]. In this study, chlorantraniliprole was also found to moderately impair the reproductive and non-reproductive behavioral traits of N. tutae, as well as its offspring survival (Table 1).…”

Inert agricultural spray adjuvants may increase the adverse effects of selected insecticides on honey bees (Apis mellifera L.) under laboratory conditions

“…Thus, bee broods seem to appear signi cantly more sensitive to certain adjuvants and co-formulants, such as NMP, than adult bees (Zuh et al 2014;Mullin et al 2015;Chen et al 2018). Moreover, chlorantraniliprole (Coragen®) is considered a highly selective insecticide (de Sousa Pereira et al 2019) and, similar to Sivanto® Prime, has a very high LD50 in contact exposure (Table 1). This may explain the lower activity of the two insecticides in combination with the adjuvants in our study.…”