Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2006
Publication Date: 3/1/2006
Citation: Cabanillas, H.E., Elzen, P.J. 2006. Infectivity of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) against the small hive beetle Aethina tumida (Coleoptera: Nitidulidae). Journal of Apicultural Research. 45(1):49-50.
Interpretive Summary: The small hive beetle, Aethina tumida, a nest parasite of honeybees, Apis mellifera, has the potential to become a global threat to apiculture and wild bee populations. This exotic pest from Africa was found destroying honeybee colonies in Florida in June 1998. Since then, adult beetles have been spreading in different states of the USA, including Texas. While the adult beetles have little impact on the colony, the larvae can cause severe damage resulting in the collapse of the nest. Environmental concerns associated with chemical pesticide usage have increased the search for alternative safe control methods. One alternative method is the use of biological control agents. Entomopathogenic nematodes have shown to be very effective in controlling other beetles of the same family of the small hive beetle. Because soil is the natural environment for these nematodes and the larvae of this beetle enters the soil to pupate near the beehive, it becomes an easy target for these nematodes. However, we lack knowledge on the practical use of the nematodes. We investigated the ability of our local nematode, Steinernema riobrave, and other nematode species to kill the beetle larvae in the soil, which is the most vulnerable insect stage. These findings will be useful to control this insect pest, which at present does not have parasites or predators as natural enemies within its native range. Such biological control methods will reduce the need for insecticide use, prevent environmental problems, and its application could prevent it from spreading by suppressing this insect pest in the soil before adult emergence.
Technical Abstract: Studies were conducted to compare the susceptibility of the small hive beetle wandering larvae to Steinernema riobrave, S. carpocapsae, and Heterorhabditis megidis in sand-substrate petri dishes at 25'C. Our results showed the beetles were susceptible to entomopathogenic nematodes. Lethal nematode concentrations required in killing 50% of treated insects (LC50) resulted lower for S. riobrave (157 nematodes per larva) and H. megidis (164 nematodes per larva) than for S. carpocapsae (204 nematodes per larva). This paper presents the first report on the pathogenicity of S. riobrave and other nematodes to control the small hive beetle. It establishes the potential of entomopathogenic nematodes to control the beetle larvae in the soil, which may be a significant factor in suppressing beetle populations before adult emergence.