Ja. Yoder et al., IMPACT OF FEEDING, MOLTING AND RELATIVE-HUMIDITY ON CUTICULAR WAX DEPOSITION AND WATER-LOSS IN THE LONE STAR TICK, AMBLYOMMA-AMERICANUM, Journal of insect physiology, 43(6), 1997, pp. 547-551
To determine whether there is a correlation between the amount of lipi
ds on the surface of ticks and their permeability to water, we quantif
ied cuticular surface wax and measured water-loss rates in the ixodid
tick Amblyomma americanum from nonfed nymph to egg-laying female. Tick
s deposited no extra cuticular lipids during feeding, permitting maxim
um transpiratory water loss that presumably helps to concentrate the b
loodmeal; and ticks deposited additional cuticular wax after apolysis
that reduced integumental water loss, which likely prepares ticks for
off-host existence. A remarkable three-fold boost in surface wax depos
ition and extreme water retention were noted after hose drop-off follo
wing feeding. This wax is likely host-derived, Fed nymphs could discri
minate between low and high relative humidity, enabling pharate adults
to conserve lipid that would otherwise be lost with the exuvia and fe
ces, This conservation strategy likely adds to the lipid pool needed b
y the tick to survive in a dry environment and complements the tick's
behavioral abilities for seeking out optimum conditions for water cons
ervation and host location. (C) 1997 Elsevier Science Ltd.