Sublethal effects of flonicamid and thiamethoxam on green peach aphid, Myzus persicae and feeding behavior analysis

Abstract

The green peach aphid, Myzus persicae Sülzer, is an important sap-sucking pest of many plants, including Chinese cabbage. The objective of the present study was to determine the effects of sublethal concentrations of two insecticides (flonicamid and thiamethoxam) and the action mechanisms on the feeding behavior of M. persicae. The median lethal concentrations (LC 50 ) of flonicamid and thiamethoxam for adult M. persicae were 2.56 and 4.02 mg/L, respectively. The sublethal concentrations of flonicamid were 0.44 mg/L (LC 10 ) and 1.25 mg/L (LC 30 ), and those of thiamethoxam were 1.19 mg/L (LC 10 ) and 2.45 mg/L (LC 30 ). The developmental period of M. persicae nymphs was 5.9 days at LC 10 and 6.1 days at LC 30 for both insecticides compared to 5.7 days for the control. Adult longevities at LC 10 and LC 30 of flonicamid were 13.2 and 13.7 days, respectively. Adult longevity at LC 10 of thiamethoxam was 14.7 days. Control adult longevity was 11.6 days. Total fecundity was higher at LC 10 (41.8 offspring/female) and LC 30 (43.0 offspring/ female) of flonicamid, and at LC 10 (42.1 offspring/female) of thiamethoxam than that of the control (29.5 offspring/female). Feeding behavior analysis using an electrical penetration graph showed that sublethal doses of flonicamid and thiamethoxam had significant effects on the duration of phloem ingestion. However, higher doses of flonicamid induced starvation by inhibition of phloem ingestion and higher doses of thiamethoxam induced contact toxicity rather than inhibition of feeding behavior. This study provides the basis for a more efficient use of these pesticides in Korea.

The toxicity of flonicamid to cotton leafhopper, Amrasca biguttula (Ishida), is by disruption of ingestion: an electropenetrography study

“…If so, then A. biguttula may have preferred to lacerate and ingest from phloem, but may have switched their ingestion to mesophyll/parenchyma on flonicamid‐treated leaves to survive slightly longer than starved insects. Cho et al . found that flonicamid induced starvation in aphids with the inhibition of phloem sap ingestion, and that lower LC 50 values of flonicamid were associated with a decrease in the duration of phloem ingestion and increase in the Np period; these findings support the results obtained in the present study.…”

Feeding response of the cotton aphid,Aphis gossypii, to sublethal rates of flonicamid and imidacloprid

“…Sublethal concentrations (LC 30 ) of flonicamid and imidacloprid shortened the nymphal period of A. gossypii . In previous work, sublethal concentrations (LC 10 and LC 30 ) of flonicamid did not affect the nymphal period of the green peach aphid, Myzus persicae (Sulzer) (Cho et al., ). Boina et al.…”

“…However, feeding behavior was not inhibited by imidacloprid even at a concentration 2× higher than that recommended. The antifeedant effects of flonicamid lead to weight loss and subsequent death from starvation for M. persicae (Morita et al., ; Cho et al., ). Low concentrations of imidacloprid have been shown to have antifeedant effects (Nauen et al., ; Han et al., ), but it did not inhibit feeding behavior in our study.…”

Sublethal Effects of Imidacloprid on Bemisia tabaci (Hemiptera: Aleyrodidae) Under Laboratory Conditions

“…Increased fecundity and reproduction after exposure to sublethal concentrations of insecticides have been reported (Morse 1998;Zanuncio et al 2003;Cutler et al 2009;Cho et al 2011). This may be one of the mechanisms of pest resurgence (Cutler et al 2009;James & Price 2002).…”