DefinePK

Abstract

Paenibacillus larvae, the causative agent of American foulbrood (AFB), poses a significant threat to honeybee (Apis mellifera) colonies, leading to serious economic losses in apiculture due to colony collapse. This study was conducted from July 2024 to December 2024 to assess the seroprevalence of AFB and evaluate the efficacy of biological treatments against P. larvae in the Dir Lower district of Khyber Pakhtunkhwa, Pakistan. A total of 254 honeybee colony samples were collected from seven localities: Kamrani-Bandagai, Khall-Tormang, Bagh Dushkhail, Samarbagh-Khema, Zolam-Arang, Talash-Nasafa, and Timergara-Khongi. Laboratory analysis was carried out at the Apiculture Rearing Museum and Pathology Laboratory, The University of Agriculture, Peshawar. Pathogen cultures of P. larvae were obtained from the National Agricultural Research Centre (NARC), Islamabad. Out of the 254 colonies, 100 tested positive for AFB, yielding an overall prevalence of 39.4%. The highest seroprevalence was recorded in Khall-Tormang (55%), followed by Timergara-Khongi (44%) and Zolam-Arang and Talash-Nasafa (both 50%), indicating moderate to high infection levels. Kamrani-Bandagai (33.3%), Samarbagh-Khema (33.3%), and Bagh Dushkhail (25%) showed relatively lower infection rates, suggesting localized outbreaks. In addition to prevalence analysis, this study evaluated the efficacy of three biological control agents: probiotics (Lactobacillus spp.), antagonistic microorganisms (Bacillus subtilis), and entomopathogenic nematodes (EPNs; Steinernema spp.). Among the treatments, probiotics exhibited the highest efficacy, reducing P. larvae density by 80% within 12 hours. Antagonistic microorganisms achieved 75% reduction over the same period, while EPNs were most effective in reducing pest abundance (80%) but had relatively lower direct impact on pathogen density. These findings highlight the urgent need for localized disease management strategies and underscore the potential of probiotics and microbial antagonists as sustainable and effective alternatives to chemical treatments in controlling AFB. The integration of such biological agents into apicultural practices may enhance honey bee health and ensure long-term productivity in regions like Dir Lower.