Trakia Journal of Sciences, No 1, pp 1-4, 2013 Copyright © 2013 Trakia University Available online at: http://www.uni-sz.bg ISSN 1313-7050 (print) ISSN 1313-3551 (online) Review THE DARKLING BEETLE (ALPHITOBIUS DIAPERINUS) – A HEALTH HAZARD FOR BROILER CHICKEN PRODUCTION Iv. Dinev* Dept. of General & Clinical Pathology, Faculty of Veterinary Medicine, Trakia University, Stara Zagora, Bulgaria ABSTRACT The purpose of this publication was to review the available literature on one of emerging and largely unknown problems related to broiler chicken production. The literature review provides data about both the life cycle of the darkling beetle, Alphitobius diaperinus (Pancer, 1797) (Coleoptera: Tenebrionidae), and the potential health risks of its presence in poultry premises. Alphitobius diaperinus is an acknowledged vector of a number of bacterial, viral and parasitic pathogens. It is also possibly involved in the hypoglycaemia spiking mortality syndrome in broilers. Analysis of author's own data is also included. Key words: Alphitobius diaperinus, broiler chickens, risk for the health, economic importance The darkling beetle, Alphitobius diaperinus in various parts of the world, including Texas (Pancer, 1797) (Coleoptera: Tenebrionidae), is and Kenya (5). It is acknowledged that larvae the most encountered beetle in the litter of feed on bat's guano, soil, sick or dead bats, poultry facilities (1). It is also called darkening chickens and pigeons (5). They could also feed or night due to its highest activity at dusk. on animal body parts, such as bird feathers or Alphitobius diaperinus usually infests flour and smaller beetles (cannibalism). other cereals, especially in poorly maintained grain storehouses (2). It has been associated with wheat, barley, rice, oat, soybean, pea, and The female darkling beetle could lay over 2,000 peanuts. It is also reported in connection with eggs (200 to 400 in average). Adults lay eggs in linseed, cottonseed, oilseeds, tobacco etc. (3). cracks or gaps of poultry facilities, in the manure Due to its tropical origins, the beetle prefers or the litter, in grain husks, and under the feed warm and humid environments. and water lines. During the duration of their life (from 3 to 12 months), they produce eggs at 1- to According to some researchers, poultry manure 5-day intervals. is rich in both adult beetles and larvae (1), while others affirm that larvae are always more Hatching of larvae takes 4 to 7 days, and the numerous than adults (4). development into adults occurs after 40 to 100 days depending on the ambient temperature and Populations of hundreds and thousands of the quality of available food. The development beetles spread by bats are found to inhabit caves requires 30-33 oС and about 90% air humidity. A ____________________________ number of studies were performed on the insect's *Correspondence to: Ivan Dinev,PhD,DVM, Dept of development conditions (3, 6, 7).The life cycle General & Clinical Pathology, Faculty of Veterinary (from egg to adult) was reported to be 89 days at Medicine, Trakia University, 6000 Stara Zagora, 22 oС and 26 days at 31 oС (6). Therefore, the Bulgaria, tel.:+359 42 699 679, temperatures in poultry facilities (between 25 E-mail:[email protected] Trakia Journal of Sciences, Vol. 11, № 1, 2013 1 DINEV IV. and 30 oС) are ideal for the development of the transmit protozoa as Eimeria spp. (3, 19); fungi beetle, and the fattening period of broilers (20, 21); and helminths as the nematode (approx. 50 days) corresponds to the completion Subulura brumpti Lopes-Neira (22); avian of the full life cycle of the beetle (8, 9). cestodes (23). Both adults and larvae of A. diaperinus could provoke intestinal obstruction Larvae feed on spilled feed, manure, sometimes (23). on dead or sick birds and cracked eggs. Mature larvae spread in all directions to find isolated Alphitobius diaperinus is possibly involved in sites for the pupal stage, often by making tunnels the etiology of the hypoglycaemia spiking into the thermal insulation of the building. mortality syndrome in broilers. The disease was Tunnels are further expanded when adult beetles successfully reproduced through beetles start looking for food. Both stages (larval and collected from the manure in the poultry facility adult) are nocturnal, and are most active at dusk. (24). They are very energetic, making holes in the litter when dispersing. Adults live for a long Recent studies relate Alphitobius diaperinus with time, normally persisting for more than a year, the occurrence of the so-called viral poult but under experimental conditions, they could enteritis complex “Runting Stunting Syndrome” live for more than 2 years (5). (25). It affects chickens 5 to 12 days of age, but older birds could be also affected. The syndrome The controlled temperature in poultry facilities, is more severe in the offspring of young breeder the constant accumulation of manure and the flocks. It is more frequent when the litter is used adequate humidity level provide favorable repeatedly and the premises remain free of birds conditions for development of darkling beetles for a shorter period. Astro- and reoviruses have all year round 10). The climate has an impact on been isolated from darkling beetle' larvae. With beetles when they are hide outdoor in the regard to rotaviruses, PCR was inconclusive. environment (11). The spatial distribution of Viral isolates, after being inoculated to 6-8-day adults benefits from the high humidity and low old chickens, succeeded to produce diarrhoea density of the soil, whereas larvae and pupae are and stunted growth (25). indifferent to humidity (9). We have also observed a high prevalence of Although the economic importance of A. adult beetles and its larvae in the litter of poultry diaperinus for grain production is minor, it is facilities in different regions of northeast, usually encountered in products, already northwest and south Bulgaria. These cases were damaged by other biological agents, mostly usually encountered with relation to diarrhoea molds. It is however essential for poultry during the first two weeks of age followed by industry as a vector of numerous avian diseases stunted growth in a large proportion of the and the related risk for the health of people, chicken population (over 15%). Parts of beetles which are in contact with the pest. Energy costs or larvae were occasionally discovered in the of buildings with thermal insulation damaged by intestinal content of some of affected chickens. the beetles are by 67% higher compared to intact premises. Darkling beetles could, however, be Another concern related to A. diaperinus is the useful in some ways. When they are active, they human health problems it could cause. Tenebroid aerate and drain the manure. beetles, including A. diaperinus, produce highly reactive benzoquinones for self-protection Diaperinus are important vectors of a number of against enemies (26). Quinones could be poultry pathogens and parasites. They spread the dangerous for human health and pose a hazard in viruses causing leukosis, Marek's disease, case of prolonged exposure to insects. Reports of Gumboro (5), turkey corona virus (12, 13), complaints related to A. diaperinus, include Newcastle disease and avian influenza viruses signs of asthma, headache, dermatitis, allergic (3). They could be vectors of bacteria such as angioedema, rhinitis, erythema (reddening) and Salmonella Typhimurium, E. coli, Aspergillus formation of papules (5, 27, 28). The exposure to spp., Staphylococcus spp. (14, 15, 16, 17), and quinone vapours could cause conjunctivites and Campylobacter spp. (18). They could also corneal ulcerations (5, 27). 2 Trakia Journal of Sciences, Vol. 11, № 1, 2013 DINEV IV. Quinones produced by tenebroids are thought to stages of the Alphitobius diaperinus (Panz.) be carcinogenic. This way, quinone-producing (Coleoptera: Tenebrionidae). Neotrop insects are hazardous to health at all stages of Entomol, 30: 365-368, 2001. production and distribution of foods (29; 30). 7. Calibeo-Hayes, D., Denning, S.S., Stringham, S.M. and Watson, D.W., Lesser CONCLUSIONS mealworm (Coleoptera: Tenebrionidae) The analysis of literature data confirms the emergence after mechanical incorporation existing risk of the presence of the darkling of poultry litter into field soils. J Econ beetle, Alphitobius diaperinus (Pancer, 1797) Entomol, 98: 229-235, 2005. (Coleoptera: Tenebrionidae) in poultry buildings 8. Erichsen, L.D. and Jespersen, J.B., for the health of birds. It is related to its role as Behaivior and population dynamics of litter vector of numerous bacterial, viral and parasitic beetles in broiler houses. Danish Pest agents, as well as to its direct effect on birds. Infestation Laboratory Annual Report, 71, Also, there is a certain risk for the health of In: Lambkin, T.A. (ed), Investigations into people in continuous contact with these insects. the management of darkling beetle, web: http//www.rirde.gov.au., 1997. The economic losses for the poultry industry are 9. Salin, C., Delettre, Y.R., Cannavacciuolo, also exacerbated by the harmful impact of M. and Veron, P., Spatial distribution of Alphitobius diaperinus on the quality of grain Alphitobius diaperinus (Panzer) used in fodder production and the higher energy (Coleoptera: Tenebrionidae) in the soil of a costs from the impaired thermal insulation of poultry house along a breeding cycle, Eur J poultry facilities. Soil Biol, 36: 107-115, 2000. REFFERENCES 10. Stafford, K.C. and Collison, C.H., Manure 1. Francisco, O. and do Prado A.P., pit temperatures and relative humidity of Characterization of the larval stages of Pennsylvania high-rise poultry houses and Alphitobius diaperinus (Panzer, 1797) their relationship to arthropod (Coleoptera: Tenebrionidae) using head populationdevelopment, Poultry Sci, 66: capsule width. Rev Bras Biol, 61 : 125-131, 1603-1611, 1987. 2001. 11. Pfeiffer, D.G. and Axtell, R.C., Coleoptera 2. Spilman, T.J., Darkling Beetles of poultry manure in caged-layer houses in (Tenebrionidae, Coleoptera). In: Gordan Nord Carolina. Environ.