18.104.22.168. Chemical killing
The use of chemicals, including water, to kill honey bees commonly occurred in the 20th century; in recent years fewer studies use this technique. Because of the dangers of cyanide, and the numerous adequate alternatives, the use of this substance is not recommended. Care should be taken when using any chemical in the laboratory or field.
Asphyxiates such as carbon dioxide or ethyl acetate can also effectively kill honey bees, provided the appropriate dose is applied. For ethyl acetate, or alternatively nail polish remover, a sealable glass killing jar <500 ml in volume and lined at the bottom with 1-2 cm of plaster of Paris can be created or purchased from a entomological supply store. Ethyl acetate should be pipetted onto the plaster until satiation, and excess liquid removed, before insects destined to be killed are introduced (Steyskal, 1986). Five minutes within the sealed container should be sufficient to kill honey bees, although this may depend on the volume of the jar, the number of individuals being killed, and the quantity of ethyl acetate provided. Care must be taken to ensure that exposed honey bees are killed, rather than anaesthetised. When maintained in the killing jar for a number of hours, or even days, individuals can still be easily manipulated because of the ability of ethyl acetates to hold moisture, although decomposition may set in. Additionally, asphyxiation by drowning can be performed using pure water, soapy water, or ethanol. The latter, when 95% pure, will also, to some extent, preserve honey bees, as well as organisms and chemical residues present within them; water will promote decomposition. As mentioned earlier (see section 22.214.171.124.1.), honey bees can also be exposed to dry ice (Naug and Gibbs, 2009) or liquid nitrogen (Zayed et al., 2005) for quick termination.