In recent years, an invasive cassava mealybug Phenacoccus manihoti has been threatening cassava cultivation alongside another invasive papaya mealybug Paracoccus marginatus which invaded the country more than a decade ago. In order to evaluate their responses against the commonly used neonicotinoid insecticides: thiamethoxam 25 WG and imidacloprid 17.8 SL, acute toxicity experiments to determine the susceptibility baselines in populations of two invasive mealybugs in the cassava agro-ecosystem, namely, cassava mealybug P. manihoti and papaya mealybug P. marginatus were performed upto 15 generations. A systemic uptake method was used for the bioassay. The LC50 values of thiamethoxam for F1 generation were 3.298 ppm whereas it was 1.066 ppm for F15 in cassava mealybug. The LC50 values of F1 generation were 2.014 ppm and that of F15 generation was 1.384 ppm when tested with imidacloprid. In the case of papaya mealybug, the LC50 values ranged from 6.138 ppm (F1) to 2.503 ppm (F15) for thiamethoxam and 7.457 ppm (F1) to 3.231 ppm (F15) for imidacloprid. All the susceptibility indices calculated were less than threefold. The rate of resistance development was negative in all cases showing that none of the tested populations harboured any resistance without insecticidal selection pressure. Tentative discriminating doses were fixed for both chemicals with the help of LC95 values obtained from the bioassay experiments, namely five ppm for both thiamethoxam and imidacloprid in the case of cassava mealybug and 10 ppm and 15 ppm, respectively, for thiamethoxam and imidacloprid in the case of papaya mealybug.
Baseline toxicity, Discriminating dose, Neonicotinoids, Paracoccus marginatus, Phenacoccus manihoti
Alexander, A., Krishnamoorthy, S. V., Kuttalam, S. & Mohankumar, S. (2013). Generating Baseline Data for Insecticide Resistance: Monitoring in Papaya Mealybug, Paracoccus marginatus (Williams and Granara de Willink). Pesticide Research Journal, 25(1), 36-41.
Anonymous (2018). Horticulture Statistics at a Glance, Ministry of Agriculture and Farmers Welfare, Govt of India
Bellotti, A. C., Smith, L. & Lapointe, S. L. (1999). Recent advances in cassava pest management. Annual Review of Entomology, 44(1), 343-370.
Bellotti, A., Herrera Campo, B. V. & Hyman, G. (2012). Cassava production and pest management: present and potential threats in a changing environment. Tropical Plant Biology, 5, 39-72.
Cook, D. R., Leonard, B. R. & Gore, J. (2004). Field and laboratory performance of novel insecticides against armyworms (Lepidoptera: Noctuiidae). Florida entomologist, 87(4), 433-439.
Dai, C., Ricupero, M., Wang, Z., Desneux, N., Biondi, A. & Lu, Y. (2021). Transgenerational effects of a neonicotinoid and a novel sulfoximine insecticide on the harlequin ladybird. Insects, 12(8), 681. https://doi.org/10.3390/insects12080681
Haas, J., Lozano, E. R. & Poppy, G. M. (2018). A simple, light clip‐cage for experiments with aphids. Agricultural and Forest Entomology, 20(4), 589-592.
Joshi, S., Pai, S. G., Deepthy, K. B., Ballal, C. R. & Watson, G. W. (2020). The cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Coccomorpha: Pseudococcidae) arrives in India. Zootaxa, 4772(1), zootaxa-4772. https://doi.org/10.11646/zootaxa.4772.1.8
LeOra. (1987). POLO-PC: a user’s guide to probit or logit analysis. LeOra Software, Berkeley, CA.
Mansion, H. & Kumar, A. (2023). Humbling Arrival of an Exotic Parasitic Wasp to Tackle Invasive Cassava Mealybug Menace in India. Vigyan Varta, 4(2): 76-78.
Nwanze, K. F. (1982). Relationships between cassava root yields and crop infestations by the, Phenacoccus manihoti. International Journal of Pest Management, 28(1), 27-32.
Odebiyi, J. A. & Bokonon-Ganta, A. H. (1986). Biology of Epidinocarsis [= Apoanagyrus] lopezi [Hymenoptera: Encyrtidae] an exotic parasite of cassava mealybug, Phenacoccus manihoti [Homoptera: Pseudococcidae] in Nigeria. Entomophaga, 31, 251-260.
Prabhaker, N., Gispert, C. & Castle, S. J. (2012). Baseline susceptibility of Planococcus ficus (Hemiptera: Pseudococcidae) from California to select insecticides. Journal of economic entomology, 105(4), 1392-1400.
Preetha, G., Stanley, J., Manoharan, T. & Kuttalam, S. (2014). Baseline toxicity of chloronicotinyls against cotton leafhopper, Amrasca biguttula biguttula, and detection of insecticide resistance. Archives of Phytopathology and Plant Protection, 47(17), 2095-2105.
Regupathy, A. and K. Dhamu. (1990). Statistics work book for insecticide toxicology: Suriya
Routray, S. & Misra, H. P. (2019). Establishment of baseline toxicity data to thiamethoxam for adult black legume aphid, Aphis craccivora Koch. by leaf dip bioassay method. Journal of Entomology and Zoology studies, 7 (4), 990-993.
Sampathkumar, M., Mohan, M., Shylesha, A. N., Joshi, S., Venkatesan, T., Gupta, A., ... & Bakthavatsalam, N. (2021). Occurrence of cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Pseudococcidae: Hemiptera), a new invasive pest on cassava in India and prospects for its classical biological control. Current Science, 25(2), 432-435. http://krishi.icar.gov.in/jspui/handle/12345678 9/475 96
Senthilkumar C. M. & Regupathy A. (2004) Generating Base Line Data for Insecticide Resistance Monitoring in Coffee Green Scale, Coccus viridis (Green) In: Resistance management from around the Globe. Resistant Pest Management 13: 5–6.
Shylesha, A. N., Joshi, S., Rabindra, R. J. & Bhumannavar, B. S. (2010). Classical biological control of the papaya mealybug. National Bureau of Agriculturally Important Insects, Banglore, India, 1-4.
Srinivas, T. (2007). Industrial demand for cassava starch in India. Starch‐stärke, 59(10), 477-481.
Stanley, J., Chandrasekaran, S. & Regupathy, A. (2009). Baseline toxicity of emamectin and spinosad to Helicoverpa armigera (Lepidoptera: Noctuidae) for resistance monitoring. Entomological Research, 39(5), 321-325.
Tanwar, R. K., Jeyakumar, P. & Vennila, S. (2010). Papaya mealybug and its management strategies.
Zhao, J. Z. & Grafius, E. (1993). Assessment of different bioassay techniques for resistance monitoring in the diamondback moth (Lepidoptera: Plutellidae). Journal of Economic Entomology, 86(4), 995-1000.
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
This work is licensed under Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) © Author (s)