Production of Pheromones by Artificially Fed Males of the Tick <I>Amblyomma Maculatum</I> (Acari: Ixodidae)

Abstract

Aggregation-attachment pheromones are produced only by male ticks of the genus Amblyomma that have imbibed blood for at least 8 d from their mammalian hosts. This report demonstrates that production and release of aggregation-attachment pheromones by Amblyomma maculatum (Koch) males can be induced in vitro by using nonblood media, artificially introduced through capillary tubes, into the male ticks. The presence of these pheromones is demonstrated by using both biological observations on bovine hosts and in vitro experimentation with petri dishes. The attraction of unfed female ticks to the artificially fed males (using the petri dish method) was significantly higher (P < 0.001) than the attraction of unfed females to unfed males. Similarly, attraction and attachment were recorded on bovine hosts. Only 62.8 +/- 17.5% of the females released attached to the bovine host. Of these, 61.9 +/- 19.37% attached around artificially fed males that were placed on the bovine 24 h earlier. This percentage did not differ significantly from the 81.4 +/- 7.1% of the total that attached around males that fed naturally for 8 d. In comparison, only 33.3 +/- 21.9% of the total number of females placed on the host did so after being fed 1 d (control group). The possibility of using capillary feeding as a new tool for investigating the physiology and reproductive behavior of blood-sucking arthropods is discussed.

Dermal gland secretion improves the heat tolerance of the brown dog tick, Rhipicephalus sanguineus, allowing for their prolonged exposure to host body temperature

“…This technique has been shown to induce dermal gland secretion (Rechav et al, 2000). This was carried out at 40 Â by light microscopy, using 20 ml graded glass capillary tubes (Fisher), in 100 Â 15 mm Petri dishes containing a strip of double-sided adhesive tape.…”

“…Most noteworthy description of this secretion is that ticks secrete when they are threatened, such as mechanical disturbance by grasping the tick's legs with forceps as though attacked by a predator, but they also secrete in response to essentially any stress, such as intense heat or flashes of bright light (Yoder et al, 1993b). Pheromonal release from these glands also occurs when ticks are artificially fed using glass capillaries (Rechav et al, 2000). After the secretion is released, the fluid covers and evaporates over the tick's body, giving the tick a residual sheen.…”

Functional Morphology of Secretion by the Large Wax Glands (Sensilla Sagittiformia) Involved in Tick Defense

“…Pressure stimulation, leg pinching that simulates attack [3] or force from blood feeding [4,18], prompts the large wax glands to activate and release copious amounts of secretion that appear as bursts of droplets that exude along the edges of the tick's body. The secretion evaporates as it spreads over the body, giving the tick a residual sheen.…”