Insecticidal Action of Glycerol Monolaurate against the Lesser Mealworm (Alphitobius diaperinus) and its Ecotoxicological Effect on Enchytraeus crypticus

Thainã Tomasi, Talyta Zortéa, Tamires Rodrigues dos Reis, Leonardo Quintana Soares Lopes, Matheus Dallamea Baldissera, Roberto Christ Vianna Santos, Dilmar Baretta, Lenita Moura Stefani, Aleksandro Schafer da Silva


Background: Alphitobius diaperinus, known as the lesser mealworm, is recognized as a problem for the poultry production sector. Several chemical methods have been employed in an attempt to control it, without successful results. Thus, alternative methods should be considered as an interesting approach to control this type of infestation. A recent study showed that glycerol monolaurate (GML) possesses insecticidal effect against bees. Therefore, the aim of this study was to evaluate, for the first time, the effect of GLM against the larval and adult forms of the lesser mealworm in vitro, and to verify whether GLM treated poultry litter used as soil fertilizer exerts any negative effect on its fauna.

Materials, Methods & Results: In vitro tests were performed using three concentrations of GLM: 0.2, 0.4 and 1 mg mL-1, and the number of dead larvae and adults of A. diaperinus was counted on days 0, 2, 5 and 8 post-treatment. Poultry litter was pulverized with 1 mg mL-1 of GML, maintained under controlled conditions for 20 days and revolved every two days. Two ecotoxicological tests were performed using Enchytraeus crypticus. In the first test, GML was applied directly into the soil at doses of 0.5, 1 and 2 mg kg-1 of soil, while the second test used poultry litter as soil fertilizer at concentrations of 0, 2, 4 and 8 tons per hectare. Insecticidal action of GML against larvae and adults of A. diaperinus where only the 1 mg mL-1 concentration showed positive effect. GML caused 100% mortality of larvae two days after the beginning of treatment. Similarly, GML showed high efficacy to control adult forms of A. diaperinus, causing 83 and 90% of mortality on days 5 and 8 post-treatment, respectively. No difference was observed while applying GML directly at doses of 0.5, 1 and 2 mg kg-1 in the TAS when compared to the control group, similarly to what was observed using poultry litter containing 1 mg/m2 of GML at concentrations of 0, 2, 4 and 8 tons per hectare compared to the control group.

Discussion: GML treatment exerted larvicidal and insecticidal action in vitro against A. diaperinus, similarly to what was observed by researchers against bees, where this product was able to eliminate 55% of the bees after 120 h of treatment. GML insecticidal mechanism of action is poorly investigated and remains unknown. However, there are evidences regarding its antimicrobial property using Staphylococcus aureus, Streptococcus spp., Enterococcus faecalis, as well as its capacity to inhibit some virulence factors linked to antimicrobial resistance. Some tests have been performed in order to reduce the use of chemical products, as Melaleuca alternifolia (tea tree oil), Ocotea odorifera (popularly known as sassafras) and Eucalyptus viminalis (popularly known as eucalypt) essential oils exerts insecticidal action against the larvae and adults of mealworms. The main chemical used to control A. diaperinus is cypermethrin, a chemical product that can damage the soil fauna due to its intensive utilization. The use of GML did not cause negative effects in the soil fauna, in disagreement other study with GML at concentrations of 50 and 100 µg mL-1 and found negative effects on the soil fauna using adults and juvenile forms of springtails (Folsomia candida) as biomarkers, showing a LD50 of 41 µg mL-1. Based on these evidences, we can suggest that the toxicity of GML to soil fauna is related to the biomarker used to determine the toxicity. Therefore, it is possible to conclude that GML possesses insecticidal action without toxic effects for the soil fauna, demonstrating potential as an alternative method to control the lesser mealworm.

Full Text:



Bautista D.A., Durisin M.D., Razavi-Rohani S.M., Hill A.R. & Griffiths M.W. 1993. Extending the shelf-life of cottage cheese using monolaurin. Food Research International. 26(3): 203-208.

Do Prado G.P., Stefani L.M., Da Silva A.S., Smaniotto L.F., Garcia F.R.M. & De Moura N.F. 2013. Alphitobius diaperinus (Coleoptera: Tenebrionidae) susceptibility to Cunila angustifolia essential oil. Journal of Medical Entomology. 50(5): 1040-1045.

Garcia M. 2004. Effects of pesticides on soil fauna: development of ecotoxicological test methods for tropical regions. [Bonn: Ecology and Development Series v.19]. Göttingen: Cuvillier Verlag, 254p.

Goodwin M.A. & Waltman W.D. 1996. Transmission of Eimeria, viruses, and bacteria to chicks: darkling beetles (Alphitobius diaperinus) as vectors of pathogens. Journal of Applied Poultry Research. 5(1): 51-55.

Hess D.J., Henry-Stanley M.J. & Wells C.L. 2015. The natural surfactant glycerol monolaurate significantly reduces development of Staphylococcus aureus and Enterococcus faecalis biofilms. Surgical Infections. 16(5): 538-542.

ISO 16387. 2004. Soil quality-effects of pollutants on Enchytraeidae (Enchytraeus sp.) determination of effects on reproduction and survival. International Organization for Standardization, Geneve, Switzerland.

ISO 11267. 1999. Soil quality - inhibition of reproduction of Collembola (Folsomia candida) by soil pollutants. International Organization for Standardization, Geneva, Switzerland.

Leschen R.A.B. & Steelman C.D. 1988. Alphitobius diaperinus (Coleoptera: Tenebrionidae) larva and adult mouthparts. Entomology News. 99(2): 221-224.

Lopes L.Q., Santos C.G., Vaucher R.A., Raffin R.P., Da Silva A.S., Baretta D., de Ávila Scheeren C. 2017. Ecotoxicology of Glycerol Monolaurate nanocapsules. Ecotoxicology and Environmental Safety. 139(1): 73-77.

Lopes L.Q., Santos C.G., Vaucher R.A., Gende L., Raffin R.P. & Santos R.C. 2016. Evaluation of antimicrobial activity of glycerol monolaurate nanocapsules against American foulbrood disease agent and toxicity on bees. Microbial Pathogenesis. 97(1): 183-188.

McAllister J.C., Steelman C.D., Newberry L.A. & Skeeles J.K. 1995. Isolation of infectious bursal disease virus from the lesser mealworm, Alphitobius diaperinus (Panzer). Poultry Science. 74(1): 45-49.

Preuss H.G., Echard B., Enig M., Brook I. & Elliott T.B. 2005. Minimum inhibitory concentrations of herbal essential oils and monolaurin for gram-positive and gram-negative bacteria. Molecular and Cellular Biochemistry. 272(1): 29-34.

Razavi‐Rohani S.M. & Griffiths M.W. 1994. The effect of mono and polyglycerol laurate on spoilage and pathogenic bacteria associated with foods. Journal of Food Safety. 14(2): 131-151.

Ruzin A. & Novick R.P. 2000. Equivalence of lauric acid and glycerol monolaurate as inhibitors of signal transduction in Staphylococcus aureus. Journal of Bacteriology. 182(9): 2668-2671.

Schlievert P.M. & Peterson M.L. 2012. Glycerol monolaurate antibacterial activity in broth and biofilm cultures. Plos one. 7(7): e40350.

Volpato A., Lorenzetti W.R., Zortéa T., Giombelli L.C., Baretta D., Santos R.C.V., Vaucher R.A., Raffin R.P., Souza, M.E., Stefani L.M., Boligon A.A., Athayde M.L. & Da Silva A.S. 2016. Melaleuca alternifolia essential oil against the lesser mealworm (Alphitobius diaperinus) and its possible effect on the soil fauna. Revista Brasileira de Ciência Avicola. 18(1): 41-46.

Wallace M.M.H., Winks R.G. & Voestermans J. 1985. The use of a beetle, Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) for the biological control of poultry dung in high-rise layer houses. Journal of the Australian Institute of Agricultural Science. 51(3): 214-219.

Zortéa T., Baretta D., Maccari A.P., Segat J.C., Boiago E.S., Sousa J.P. & Da Silva A.S. 2015. Influence of cypermethrin on avoidance behavior, survival and reproduction of Folsomia candida in soil. Chemosphere. 122(1): 94-98.


Copyright (c) 2018 Thainã Tomasi, Talyta Zortéa, Tamires Rodrigues dos Reis, Leonardo Quintana Soares Lopes, Matheus Dallamea Baldissera, Roberto Christ Vianna Santos, Dilmar Baretta, Lenita Moura Stefani, Aleksandro Schafer da Silva

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.