Attempts to feed Amblyomma variegatum ticks on artificial membranes

Feeding jars were used to feed nymphs of Amblyomma variegatum on blood of goats or cattle. Sterile blood was collected daily or weekly (kept at 4 degrees C or frozen until use), with addition either of heparin alone or of heparin and antibiotics/fungicide or of heparin, adenosine triphosphate and glutathione. Membranes were made of a thin (0.12-0.32 mm) film of silicone mastic. Blood in the jars was replaced twice a day, and reached a temperature of 39 degrees C in a waterbath before it became available to the ticks. Attachment of nymphs was stimulated by dropping on the membrane fresh goat hair and squamae collected close to prefed males, skin washing and natural pheromone extracts. Using these devices, attachment of nymphs is rapid and intense (68%). Their body mass when engorged and the molting success, were lower than that of naturally fed ticks. Furthermore, the proportion of engorging ticks was usually much less and the length of the blood meal was much longer than of naturally fed ticks. The best results were obtained with fresh goat blood or cattle blood with antibiotics. Further developments are needed before this method can be used routinely.