Performance of Commercial Insecticide Formulations Against Different Developmental Stages of Insecticide-Resistant Tropical Bed Bugs (Hemiptera: Cimicidae)

Abstract

This study examined the presence of insecticide resistance in different developmental stages (adults, first instars, and eggs) of the tropical bed bug, Cimex hemipterus (F.) using several insecticide formulations. Adults and first instars of five strains (Queensland, Kuala Lumpur, Bukit Mertajam, Saujana, and Krystal Point) were evaluated using the surface contact method and compared with a susceptible strain (Monheim) of the common bed bug Cimex lectularius L. The insecticide formulations were used at their label rates in this study: Tandem (thiamethoxam [11.6%], lambda-cyhalothrin [3.5%]) at 183.96 mg/m2; Temprid SC (imidacloprid [21%], beta-cyfluthrin [10.5%]) at 106.13 mg/m2; Sumithion 20CS (fenitrothion [20%]) at 250 mg/m2; Pesguard FG161 (d-tetramethrin [4.4%], cyphenothrin [13.2%]) at 110 mg/m2; and Sumithrin 10SEC (d-phenothrin [10%]) at 100 mg/m2. Results showed a very high level of resistance to Pesguard FG161 (388.3 to >605.0 times) and Sumithrin (302.9 to >365.5 times) in all adults of the strains tested, whereas low to high levels of resistance were registered for Tandem (1.4–4.7 times), Temprid (7.3–16.7 times), and Sumithion (1.2–14.6 times) for adults of all bed bug strains. For first instars, resistance to the former two formulations were high to very high (31.4–118.1 times). In contrast, they showed lower resistance to Tandem, Temprid, and Sumithion (1.0–10.2 times). An immersion method used to test on bed bug eggs found high to very high resistance toward all tested formulations. Results demonstrate that the resistance level varies between bed bug developmental stages.

Cuticle thickening associated with fenitrothion and imidacloprid resistance and influence of voltage‐gated sodium channel mutations on pyrethroid resistance in the tropical bed bug, Cimex hemipterus

“…We also noticed that all the three pyrethroid‐resistant C. hemipterus strains (SEL_MY, PEN2_MY, and KUL_MY) carrying the M918I and L1014F mutations were also resistant to fenitrothion and imidacloprid (Table 2). This finding suggests that multiple resistance mechanisms against various classes of insecticides may exist within each population, which was consistent with previous reports 19,33,51 . To understand this further, we investigated if metabolic enzyme activities also contributed to the observed phenomena.…”

Insecticide Resistance of Cimex lectularius L. Populations and the Performance of Selected Neonicotinoid-Pyrethroid Mixture Sprays and an Inorganic Dust

“…Cotton and Indy populations exhibited RR 50 for deltamethrin less than 2.0, but the mortality was only 73% and 67%, respectively. Similarly, Leong et al [ 56 ] found that bed bugs treated with Tandem insecticide showed a RR 50 value of 1.4 but the mortality was only 53%. The key mechanisms causing pyrethroid resistance among bed bugs are overexpression of detoxification enzymes and the target site insensitivity ( kdr -type mutation) [ 57 , 58 ].…”

“…One population (Irvington, Table S1 ) had a RR 50 > 160 after being maintained in the laboratory for approximately 10 yr. Likewise, C. hemipterus exhibited high resistance (RR 50 > 600) to neonicotinoid-pyrethroid mixture insecticides after a 14 yr maintenance without exposure to insecticides [ 56 ]. The bed bug resistance to insecticides may therefore not degrade as rapidly as aforementioned.…”

Bacterial symbionts influence host susceptibility to fenitrothion and imidacloprid in the obligate hematophagous bed bug, Cimex hemipterus

“…Chemical control based on the application of residual insecticides remains the primary choice for managing bed bugs infestations 19 , 21 . Numerous studies have reported insecticide resistance in bed bugs to most major insecticide classes including pyrethroid 24 – 27 , organophosphate 28 – 31 , neonicotinoid 32 , carbamate 31 , chlorinated hydrocarbons 33 , 34 , and phenylpyrazole 35 . Several mechanisms have been identified to explain the reduced efficiency of insecticides in bed bugs which include penetration resistance due to enhanced cuticle thickness 36 , metabolic resistance due to enhanced expression of xenobiotic metabolizing enzymes 29 , and reduced target site sensitivity due to mutations that causes binding inefficiency of pyrethroids in the voltage gated sodium channels 24 , 25 , 37 .…”