Arabian sandflies (Diptera: Psychodidae) prefer the hottest nights?

D. M. ROBERTS*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)

Abstract

Abstract. A vehicle‐mounted net was used to collect hourly samples of sandflies on 15 nights during June in northern Oman. Every half hour, the temperature, relative humidity, wind velocity and light intensity were measured (there was no cloud or rainfall during this period). The sandflies caught were mainly Phlebotomus alexandri and Sergentomyia clydei. Their circadian activity increased rapidly after sunset (18.50 hours). The high level of activity was fairly constant during 9 h of darkness until dawn, when it decreased rapidly. A few flies were still active at 07.00 hours, 1.5 h after sunrise. A multiple regression showed that the main factor affecting sandfly activity was light intensity. When this factor was removed, by considering only the 135 catches collected during the 9 h of darkness, the second most important factor was low relative humidity, followed by low wind velocity. Temperature was not a significant factor in the analysis, because of its strong negative correlation with humidity. However, when the effect of humidity was removed from the regression, high temperature became significant, but less important than wind. The regressions showed that, for flight activity, the optimum humidity was around 10%; the probable maximum wind velocity was 3.5 ms‐1 and 11oC was the probable minimum temperature. Thus, when the 4 nights with highest catches (200–260 flies/night) were compared with the 4 nights with lowest catches (50–120 flies/night), the best nights had a low humidity (10–25%) and low wind speed (<0.3ms‐1) in combination with highest temperatures (31–43oC).

Original languageEnglish
Pages (from-to)194-198
Number of pages5
JournalMedical and Veterinary Entomology
Volume8
Issue number2
DOIs
Publication statusPublished - Apr 1994

Keywords

  • Oman.
  • Phlebotominae
  • Phlebotomus alexandri
  • Sergentomyia clydei
  • light intensity
  • relative humidity
  • sandfly activity
  • temperature
  • vehicle‐mounted net
  • wind velocity

ASJC Scopus subject areas

  • Parasitology
  • Ecology, Evolution, Behavior and Systematics
  • veterinary(all)
  • Insect Science

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