Host-seeking behaviour of tracheal mites (Acari: Tarsonemidae) on honey bees (Hymenoptera: Apidae)

Abstract

The behaviour of the endoparasitic tracheal mite, Acarap& woodi (Rennie) on honey bees (Apis mellifera L.) is a challenge to observe because of its small size. Through a microscope, we videotaped this mite's movement on young bees, dead bees and bees exposed to vegetable oil. Previous studies have shown that solid vegetable oil decreases mite infestations in a bee colony. We hypothesized that the oil alters mite behaviour to the detriment of the parasite, thus helping to safeguard the host. Habitat-seeking behaviour, identified as necessary for mites to locate a new host environment, was disrupted on both dead and oil-treated bees. Questing behaviour, which is associated with transfer between hosts, increased significantly on the dead and oily bees. The behaviours of mites were sig~2ificantly different between all three treatments (;(2=494.96, p < 0.001 on dead bees and Z =851.11, p < 0.001 on oily bees). Both questing and seeking behaviours were significantly different on each of the thoracic treatments (F2,66 = 7,88, p < 0.001 and F2,66 =21.28, p < 0.001) and mite questing behaviour was not altered between males and females on live or oily bees (F1,22 =0.25, p < 0.62), but habitat seeking was (F1,22 = 7.42, p < 0.012). The male questing and habitat-seeking behaviours were observed. We conclude that oiltreated bees gained protection from habitat-seeking mites because the normal behaviour of the mites seeking an oviposition site is interrupted.

Standard methods for tracheal mite research

“…(Giordani, 1962). An exposed mite will die after a few hours unless it enters a host; they are also at risk of being dislodged during bee flight and grooming (Sammataro and Needham, 1996;Sammataro et al, 2000). In infested and crowded tracheal tubes, males move about and locate pharate nymphal females that are about to moult to adulthood and guard them in advance of mating (Ochoa et al, 2005).…”

“…The lobe, spiracle, and most of the main tracheal trunk will be removed together. This technique was subsequently used by Phelan et al (1991), Bruce et al (1991), and Sammataro and Needham (1996) …”

Brood pupation temperature affects the susceptibility of honeybees (Apis mellifera) to infestation by tracheal mites (Acarapis woodi)

“…Mated females leave the tracheae to seek a new host bee moving from bee to bee 98 J.B. McMullan, M.J.F. Brown via the pleural hair (Hirschfelder and Sachs, 1952;Sammataro and Needham, 1996). The success rate of these foundress female mites entering the tracheae of new hosts was identified as the likely factor that made certain strains of honeybee susceptible or resistant to tracheal mite infestation (Danka and Villa, 1996).…”

Observations on the honey bee tracheal mite Acarapis woodi (Acari: Tarsonemidae) using low-temperature scanning electron microscopy

“…Adult females are known to disperse and use the tarsal claws and setae on the fourth pairs of legs to successfully move from bee to bee (Sammataro and Needham 1996). However, the use of tarsal claws by adults within the tracheal tube appears to be limited.…”