Adult
OverviewAdults can be identified from other insects by their behaviour, appearance, size etc. (see there) Both sexes feed on plant sugars (Lewis and Domoney, 1966). Killick-Kendrick (1979) also describes honeydew of aphids and coccids as possible source.
In studies (Chaniotis, 1974) it as been shown that some sugars are preferred to others which could mean that preferences for particular plants may restrict the distribution of the insect and thus also of possible transmissible parasites. The type of sugar and the frequency of uptake may be a factor in the insect's ability to transmit leishmaniosis. Plant sugars may be essential for parasite survival and promastigotes require carbohydrates for their development (Killick-Kendrick, 1978).
Only females feed on blood, which is suspected as a source of protein for egg development. When seeking food sand flies normally have a characteristic short hopping flight.
Females require the blood meal to mature about 80-100 eggs and the time from engorgement to oviposition is not less than 6 days (demonstrated in Mediterranean species) (Killick-Kendrick and Killick-Kendrick, 1999).
Males are attracted to females when those are feeding and will mate with them even while the females are taking a blood meal. Mating behavior of sand flies differs between species, with some males arriving on the host before the female, courting the females when they come to feed (Jarvis and Rutledge, 1992; Lane et al., 1990). Others ride on the back of the female before copulation (Valenta et al., 2000), whereas Ph. ariasi is suggested to mate after the females have fed (Killick- Kendrick and Killick-Kendrick, 1999). Life ExpectancyLife expectancy has hardly been determined for wild female sand flies. Killick-Kendrick et al. (1984) recaptured marked Ph. ariasi 28 days after release. AutogenyAutogeny i.e. the ability to produce eggs without a bloodmeal has been reported for some sand fly species (Johnson, 1961; Schmidt, 1965) and suspected for others (Lewis et al., 1970). But it is less common than in mosquitoes (Killick-Kendrick, 1978). Autogeny may help a sand fly population to increase quickly. Thus bring a rapid onset of the maximum Leishmania transmission period (Lewis, 1971). While it has not been demonstrated for the Mediterranean vectors (Killick-Kendrick and Killick-Kendrick, 1999).
In nature, more than one gonotrophic cycle is considered normal (Dolmatova, 1942), whereas in the laboratory, most gravid females lay eggs and die either as they lay or shortly afterwards.
For some subgenera of Phlebotomus the females are gonotrophically concordant and take one blood meal each gonotrophic cycle (Killick-Kendrick and Killick-Kendrick, 1999).
Most Leishmania species complete their life-cycle within a single ovarian cycle of the sand fly, and parasites may therefore be transmitted at the first bloodmeal after an infective feed. But in some (L. d. donovani and some strains of L. d. infantum) the development is not complete until after the second bloodmeal. This means full life cycles cannot be demonstrated under laboratory conditions when sand flies do not survive oviposition (Killick-Kendrick, 1978).
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