Susceptibility of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidea) to gamma-cyhalothrin under laboratory conditions

Abstract

Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) is an important biological control agent of the cotton leafworm [Alabama argillacea (Hübner)] in the cotton crops in Brazil. The use of selective products such as pyrethroids has been emphasized in this agroecosystem. Then, the susceptibility of the predatory stinkbug P. nigrispinus to the pyrethroid insecticide gamma-cyhalothrin was studied in the laboratory. Nymphs and adults of the predator were exposed to seven concentrations of the gamma-cyhalothrin via topical contact and ingestion through treated water. The concentrations studied of this insecticide via topical application were relatively harmless for adults of P. nigrispinus (females: LC 50 = 143.5 ppm a.i., and males: LC 50 = 145.1 ppm a.i.) and 5th-instar nymphs (LC 50 = 103.9 ppm) as compared to via ingestion (females: LC 50 = 1.98 ppm a.i., males: LC 50 = 1.91 ppm a.i., and 5th-instar nymphs: LC 50 = 2.05 ppm a.i.). The use of pyrethroids and beneficial insects in IPM programs should be better evaluated. Key words: cotton, biological control, pyrethroid, selectivity, natural enemies SUSCETIBILIDADE DE Podisus nigrispinus (DALLAS) (HETEROPTERA: PENTATOMIDAE) A GAMMA-CYHALOTHRIN SOB CONDIÇÕES DE LABORATÓRIORESUMO: Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) é um importante agente de controle biológico do curuquerê [Alabama argillacea (Hübner)] na cultura do algodão no Brasil. O uso de produtos seletivos tais como piretróides tem sido enfatizado no agroecosistema do algodoeiro. Portanto, estudou-se em laboratório a suscetibilidade do percevejo predador Podisus nigrispinus (Dallas) ao inseticida piretróide gamma-cyhalothrin. As exposições via ingestão e aplicação tópica de ninfas de 5 o ínstar, fêmeas e machos de P. nigrispinus a gamma-cyhalothrin foram feitas, usando-se sete concentrações do inseticida. Gammacyhalothrin via aplicação tópica foi relativamente menos tóxico às formas adultas de P. nigrispinus (fêmeas: CL 50 = 143,5 ppm i.a. e machos: CL 50 = 145,1 ppm i.a.) e às ninfas de 5 o ínstar (CL 50 = 103,9 ppm) desse predador, quando comparado a sua utilização por ingestão (fêmeas: LC 50 = 1,98 ppm i.a., machos: LC 50 = 1,91 ppm i.a. e ninfas de para ninfas de 5 o instar: LC 50 = 2,05 ppm i.a.). Os resultados dessa pesquisa sugerem que o uso de piretróides em programas de MIP deve ser avaliado com bastante cautela. Palavras-chave: algodão, controle biológico, piretróide, seletividade, inimigo natural

Effect of insecticides on predatory assassin bug, <i>Sycanus collaris</i> (Fabricius) (Hemiptera: Reduviidae)

“…In the present study, mortality rate of adults is relatively lesser than the nymphs. This result corroborates with the findings of Pereira et al (2005), who reported that gamma cyhalothrin (P) is more toxic against Podisus nigripinus Dallas (Hemiptera: Pentatomidae) in the nymph than in the adult stage, perhaps due to the thicker cuticle of adults compared to that of nymphs. Curkovic et al (2007) reported that some insects, particularly adults, are protected against the entry of insecticides by thick and sclerotized cuticles and that larvae and nymphs become progressively less permeable as their cuticle thickens.…”

Effects of imidacloprid-sodium chloride association on survival and reproduction of the stink bug Podisus nigrispinus

“…The neonicotinoids had been reported as molecules that did not affect the oviposition and egg hatch of treated female adults of Podisus sp. and showing lower mortality and survival impacts compared with to residual toxicity of pyrethroid molecules (De Cock et al, 1996;Tillman and Mullinix, 2004;Torres and Ruberson, 2004;Pereira et al, 2005). These results suggest that the viability of the eggs was not affected by the imidacloprid with or without salt but the fertility of this predator was reduced in agreement with results for pesticides reducing mature oocytes and increasing the maturation period of P. nigrispinus (Reis et al, 2018).…”

Selectivity of insecticide use in soybean crop to the predator Podisus nigrispinus (Hemiptera: Pentatomidae)

“…Thus, despite the greater selectivity to the adult stage, those products might also have sublethal effects on adults. The higher IGRs selectivity to adults may be related to the higher degradation capacity of the molecule by the P. nigrispinus adult and thus, its ability to avoid direct contamination or deleterious effects in later generations (PEREIRA et al, 2005). Water: y= 9.9 -0.5x (R 2 =0.6971; p<0.0001) Lufenuron: y= 10.7 -1.9x (R 2 =0.8913; p<0.0001) Teflubenzuron: y= 10.5 -1.3x (R 2 =0.8341; p<0.0001) Triflumuron: y= 9.7 -1.5x (R 2 =0.5756; p<0.0001) Tebufenozide: y= 9.7 -1.2x (R 2 =0.4517; p<0.0001) Clorfluazuron: y= 9.9 + 0.3x -0.3x 2 (R 2 =0.8480; p=0.0004) Novaluron: y= 10.1 -0.3x -0.2x 2 (R 2 =0.7826; p=0.0419) Methoxyfenozide: y= 10.4 -1.0x (R 2 = 0.5730; p<0.0001) Chlorpyrifos*: y= 2.8 -1.5x + 0.2x 2 (R 2 =0.7857; p<0.0001) Water: y= 10.2 -0.8x (R 2 =0.5975; p<0.0001) Lufenuron: y= 10.3 -1.0x (R 2 =0.5468; p<0.0001) Teflubenzuron: y= 9.6 -0.8x (R 2 =0.6328; p<0.0001) Triflumuron: y= 9.7 -0.8x (R 2 =0.5060; p<0.0001) Tebufenozide: y= 9.6 -0.7x (R 2 =0.7647; p<0.0001) Clorfluazuron: y= 10.3 -0.7x (R 2 =0.7893; p<0.0001) Novaluron: y= 9.6 -0.5x (R 2 =0.5584; p<0.0001) Methoxyfenozide: y= 10.1 -0.4x (R 2 = 0.4247; p=0.0001) Chlorpyrifos*: y= 2.8 -1.5x + 0.2x 2 (R 2 =0.7857; p<0.0001) Among the evaluated products, the most selective for P. nigrispinus were those belonging to the spinosyns (spinosad and spinetoram) group ( Figure 1) as well as the diamides group (flubendiamide and chlorantraniliprole) (Figure 3), which were classified as harmless (class 1) and slightly harmful (class 2) for both nymphs and adults of P. nigrispinus (Table 2).…”