2020
Shikano, I. 2020. Efficacy of a Fungal Biopesticide for Bed Bug Management is Influenced by the Toxicity and Associated Behavioral Avoidance of Harborages on Insecticide-Impregnated Box Spring Covers. Journal of Economic Entomology 113 (6): 2850-2857. doi:10.1093/jee/toaa227.
“Bed bugs spend most of their lives hiding in harborages, usually in the seams of mattresses and box springs and in crevices of bed frames. For insecticidal products that target these shelters, the repellency of the products for bed bugs may influence their duration of contact. Bed bugs are known to avoid contacting surfaces treated with certain insecticides. The fungal biopesticide Aprehend contains spores of the entomopathogen, Beauveria bassiana. It is sprayed around bed frames, box springs, and furniture where bed bugs are likely to walk, which includes potential shelters. Here, I investigated the influence of a permethrin-impregnated cover, ActiveGuard, on bed bug sheltering behavior and the effectiveness of combining ActiveGuard with Aprehend. Bed bugs avoided harboring in a shelter constructed with ActiveGuard compared to a nontoxic encasement-type cover. This avoidance behavior reduced mortality induced by ActiveGuard shelters compared to forced continuous contact on the ActiveGuard cover. However, while bed bugs also avoided Aprehend-treated ActiveGuard shelters, the combined treatment induced almost complete mortality and more quickly than Aprehend-treated shelters made of the encasement-type cover. This suggests compatibility between the two integrated pest management (IPM) tools even though the bed bug’s avoidance behavior would suggest otherwise. Since Aprehend is highly effective against pyrethroid-resistant bed bugs, its use would provide more effective control where bed bug populations are more resistant to the permethrin-impregnated cover.”
2018
Aak, A., H. Morten, and B. A. Rukke. 2018. Insect pathogenic fungi and bed bugs: behaviour, horizontal transfer and the potential contribution to IPM solutions. Journal of Pest Science. 91(2):823-835. doi: 10.1007/s10340-017-0943-z
“The increasing problem of bed bugs requires the development of new control strategies, and insect pathogenic fungi can contribute towards management. We used laboratory bioassays with Isaria fumosoroseus, Lecanicillium muscarium and Beauveria bassiana to evaluate their virulence to the bed bug. Only B. bassiana significantly affected bed bug survival and was dependent on dose and formulation. A 2% B. bassiana oil formulation induced horizontal transfer to elevate mortality in a 10-day arena bioassay. Temporal distribution of contagious individuals and increasing the dose from 2 to 4% did not increase mortality. Horizontal transfer mainly occurred between adults, and only partly between adults and nymphs. Bed bugs showed activity peaks during the night, and activity was increased by elevated levels of CO2. Distribution between harbourages was not affected by CO2 activation, level of infection or the bio-pesticide, and horizontal transfer was not dependent on the degree of aggregation. Movement in the arenas negatively affected horizontal transfer when the number of susceptible individuals was large. Level of infection also influenced behaviour as the bed bug movement increased with elevated disease burden. The use of fungi as a part of an integrated pest management strategy seems to be an interesting option that should be investigated further. B. bassiana kills bed bugs and can be carried to harbourages to target hidden individuals.”
Pietri, J. E., and D. Liang. 2018. Virulence of entomopathogenic bacteria in the bed bug, Cimex lectularius. Journal of Invertebrate Pathology. 151: 1-6. doi: 10.1016/j.jip.2017.10.004
“Due in part to the development of insecticide resistance, the common bed bug, Cimex lectularius, has overcome human intervention efforts to make a global resurgence. The failure of chemical pesticides has created a need for novel strategies to combat bed bugs. While a number of insect pests are susceptible to the use of entomopathogenic microbes or microbial-derived toxins, biological control methods have not been thoroughly explored in bed bugs. Here, we tested the virulence of three entomopathogenic bacterial species in C. lectularius to determine their potential for bed bug control. We examined bed bug survival after inoculation with live or heat-killed Serratia marcescens, Pseudomonas fluorescens, and Bacillus thuringiensis israelensis at varying temperatures. We also analyzed the viability and growth of the same bacteria in infected bed bugs. All three bacterial species were pathogenic to bed bugs. However, the effects of S. marcescens and P. fluorescens were temperature-dependent while the lethality of B. thuringiensis israelensis was not. In addition, bacterial virulence was partly dependent on the route of infection but was not strongly associated with proliferation. Thus, our results suggest multiple possible mechanisms of microbial pathogenicity in the bed bug and indicate that entomopathogenic bacteria, or products derived from them, may have useful applications for bed bug control.”
2017
Barbarin, A. M., G. S. Bellicanta, J. A. Osborne, C. Schal, and N. E. Jenkins. 2017. Susceptibility of insecticide-resistant bed bugs (Cimex lectularius) to infection by fungal biopesticide. Pest Management Science. 73(8): 1568–1573. doi: 10.1002/ps.4576
“Bed bugs are a public health concern, and their incidence is increasing worldwide. Bed bug infestations are notoriously difficult to eradicate, further exacerbated by widespread resistance to pyrethroid and neonicotinoid insecticides. This study evaluated the efficacy of the newly developed fungal biopesticide Aprehend™, containing Beauveria bassiana, against insecticide-resistant bed bugs. Overall mortality for the Harold Harlan (insecticide-susceptible) strain was high (98–100%) following exposure to Aprehend™ or Suspend SC (deltamethrin). The mean survival times (MSTs) for Harold Harlan bed bugs were 5.1 days for Aprehend™ and 4.8 and 3.0 days for the low and high concentrations of Suspend SC respectively. All three strains of pyrethroid-resistant bed bugs were susceptible to infection by B. bassiana, resulting in MSTs of <6 days (median = 4 days) and >94% overall mortality. Conversely, mortality of the three insecticide-resistant strains after exposure to Suspend SC was only 16-40%. These results demonstrate that Aprehend™ is equally effective against insecticide-susceptible and insecticide-resistant bed bugs and could provide pest control operators with a promising new tool for control of bed bugs and insecticide resistance management.”
Zahran, Z., N. M. I. Mohamed Nor, H. Dieng, T. Satho, and A. H. Ab Majid. 2017. Laboratory efficacy of mycoparasitic fungi (Aspergillus tubingensis and Trichoderma harzianum) against tropical bed bugs (Cimex hemipterus) (Hemiptera: Cimicidae). Asian Pacific Journal of Tropical Biomedicine. 7(4): 288–293. doi: 10.1016/j.apjtb.2016.12.021
“To test the effectiveness of conidial spore formulations [Aspergillus tubingensis (A. tubingensis) and Trichoderma harzianum (T. harzianum)] against tropical bed bugs, Cimex hemipterus. Spore formulations were made from two fungal strains, T. harzianum and A. tubingensis. The bed bugs were exposed to the conidial spores placed soaked onto a fabric cloth for 1 h and the mortality counts were recorded daily until 14 days. Mean survival times based on Kaplan–Meier survival analysis showed no significant differences between all the concentrations in both the fungal isolates: T. harzianum and A. tubingensis. However, the evaluation of both the isolates in terms of virulence resulted in low lethal hours in all the concentrations except for the high concentration of A. tubingensis (LT50 = 44.629 h) at the conidial exposure of 1 × 106 spores/mL. Rapid mortality of the bed bugs was observed from Day 6 to Day 12, ranging from 13% to 90% in all three concentrations of A. tubingensis. With reference to the T. harzianum exposure, the concentration of 1 × 104 spores/mL displayed a gradual increase in the percentage mortality of 90 on Day 14. Approaches to the bed bugs treatment should be explored in-depth using a natural biological agent like fungus especially A. tubingensis to reduce this pest population, in order to replace chemical methods.”
2015
Ab Majid, A. H., Z. Zahran, A. H. Abd Rahim, N. A. Ismail, W. Abdul Rahman, K. S. Mohammad Zubairi, H. Dieng, and T. Satho. 2015. Morphological and molecular characterization of fungus isolated from tropical bed bugs in Northern Peninsular Malaysia, Cimex hemipterus (Hemiptera: Cimicidae). Asian Pacific Journal of Tropical Biomedicine. 5: 707–713. doi: 10.1016/j.apjtb.2015.04.012
“To investigate some morphological and molecular characteristics of fungal parasites isolated from wild tropical bed bug, Cimex hemipterus. A series of culture methods were used to obtain fungal isolates from field-collected bed bugs. Characteristics of the isolates such as colony appearance, mycelial texture and pigmentation were studied to explore their morphology. Isolates were also subjected to a PCR-based genotyping test. There were noticeable differences in morphological characteristics among the four isolates. Conidial areas of one isolate were dark green, whereas those of the remaining colonies were olive-green, black or dark brown. Conidia of the dark green isolate were globose, while those of olive-green, black and dark brown isolates were globose to subglobose, globose to spherical and globose to subglobose/finely roughened, respectively. These morphological specificities and the molecular analyses showed that the fungal internal transcribed spacer ribosomal region and β-tubulin gene sequences of the isolates shared clade with Trichoderma and Aspergillus sequences. Overall, the new discovery of common pathogens in agricultural field developed in live bed bugs storage tank may initiate the use of biological agents in later years.”
2014
Ulrich K. R., M. F. Feldlaufer, M. Kramer, and R. J. St. Leger. 2014. Exposure of bed bugs to Metarhizium anisopliae at different humidities. Journal of Economic Entomology. 107(6): 2190-2195. doi: 10.1603/EC14294
“Bed bugs Cimex lectularius L. were exposed to conidia (spores) of the entomopathogenic fungus Metarhizium anisopliae by feeding, aerosol spray, or contact with a treated surface. Feeding experiments demonstrated that bed bugs were innately susceptible to this fungus. However, only at 98% humidity were mortality rates high, regardless of whether bed bugs were sprayed with a fungal solution or contacted a treated surface. Mortality in treated bed bugs at ambient humidity did not increase when these bed bugs were kept in aggregation with other bed bugs that had recently blood fed to repletion. Based on these laboratory studies, we conclude that M. anisopliae is a poor pathogen for use in control of bed bugs, particularly at humidities that would likely be encountered under field conditions.”
2012
Barbarin, A. M., N. E. Jenkins, E. G. Rajotte, and M. B. Thomas. 2012. A preliminary evaluation of the potential of Beauveria bassiana for bed bug control. Journal of Invertebrate Pathology. 111(1): 82–85. doi: 10.1016/j.jip.2012.04.009
“Residual biopesticide treatments of Beauveria bassiana were tested against the bed bug Cimex lectularius. An oil formulation of conidia was applied to different substrates. Bed bugs were exposed for 1 h, transferred to an unsprayed environment and monitored for mortality. Separate bioassays evaluated the effect of bed bug strain, sex, life stage, and exposure substrate on mortality. Rapid mortality was observed in all bioassays, with bed bugs exposed to treated jersey knit cotton dying most rapidly. A further assay demonstrated efficient autodissemination of conidia from exposed bed bugs to unexposed bed bugs within artificial harborages.”