Effectiveness of synthetic versus natural human volatiles as attractants for Anopheles gambiae (Diptera: Culicidae) sensu stricto

Females of the African malaria vector, Anopheles gambiae Giles sensu stricto, use human volatiles to find their blood-host. Previous work has shown that ammonia, lactic acid, and aliphatic carboxylic acids significantly affect host orientation and attraction of this species, In the current study, these compounds were tested for their attractiveness relative to human emanations in vivo and in vitro. Emanations from a human hand, incubated sweat, and foot skin residues on a nylon sock were significantly attractive when tested against clean air. In a dual-choice test, foot skin residues were significantly more attractive than emanations from a human hand in vivo. Ammonia alone attracted more mosquitoes than fresh or incubated sweat, However, the odor of a human hand or of foot skin residues were more attractive than ammonia. A known attractive blend of ammonia with lactic acid and carboxylic acids was less effective than natural foot odorants, The results demonstrate that the synthetic blend based on skin odor is attractive for An. gambiae, but that in a choice situation in vitro natural skin odors are still preferred by the mosquito. Differences in volatile organic compound abundances between a worn sock and the synthetic blend may have resulted in stronger attraction to the sock. This suggests that candidate attractants should be evaluated with consideration of the strength of natural odorant sources, The data furthermore suggest that additional unidentified compounds from the human foot are involved in the host-seeking behavior of this mosquito species

Innate preference for host-odor blends modulates degree of anthropophagy of Anopheles gambiae sensu lato (Diptera: Culicidae)

In field studies, Anopheles gambiae Giles sensu stricto obtains most blood meals from humans, whereas Anopheles quadriannulatus Theobald bites predominantly bovids. We investigated whether host odors modulate the host preference of these mosquito species. In a dual-choice olfactometer, mosquitoes were given a choice between clean air and putative host-specific odor blends. An. gambiae chose ‘human odor’ over clean air and clean air over ‘cow odor.’ Although Anopheles quadriannulatus did not choose cow odor over clean air, it chose clean air over human odor. Cheese odor, which attracted An. gambiae, did not result in higher trap catch of An. quadriannulatus. We conclude that the degree of anthropophagy of An. gambiae s.l. has an innate olfactory basis

The effect of water turbidity on the near-surface water temperature of larval habitats of the malaria mosquito Anopheles gambiae

Water temperature is an important determinant in many aquatic biological processes, including the growth and development of malaria mosquito (Anopheles arabiensis and A. gambiae) immatures. Water turbidity affects water temperature, as suspended particles in a water column absorb and scatter sunlight and hence determine the extinction of solar radiation. To get a better understanding of the relationship between water turbidity and water temperature, a series of semi-natural larval habitats (diameter 0.32 m, water depth 0.16 m) with increasing water turbidity was created. Here we show that at midday (1300 hours) the upper water layer (thickness of 10 mm) of the water pool with the highest turbidity was on average 2.8 degrees C warmer than the same layer of the clearest water pool. Suspended soil particles increase the water temperature and furthermore change the temperature dynamics of small water collections during daytime, exposing malaria mosquito larvae, which live in the top water layer, longer to higher temperatures

PATHOLOGICAL STUDIES OF THE "BUD BLIGHT" OF MULBERRY TREES : II. ON THE INFLUENCE OF MANURE UPON THE DEVELOPMENT OF THE DISEASE AND THE FORMATION OF SPORODOCHIA AND PERITHECIA OF THE CAUSAL FUNGUS

ArticleJournal of the Shinshu University. 3: 43-82(1953)departmental bulletin pape

STUDIES IN THE CONCEPTS OF THE SPECIES AND THE PHYSIOLOGIC FORM IN FUSARIUM CAUSING THE BUD BLIGHT OF MULBERRY TREES

ArticleJournal of the Faculty of Textiles and Sericulture, Shinshu University. Series A, Biology 1: 45-83(1951)departmental bulletin pape

PATHOLOGICAL STUDIES OF THE "BUD BLIGHT" OF MULBERRY TREES : II. ON THE INFLUENCE OF MANURE UPON THE DEVELOPMENT OF THE DISEASE AND THE FORMATION OF SPORODOCHIA AND PERITHECIA OF THE CAUSAL FUNGUS

ArticleJournal of the Faculty of Textiles and Sericulture, Shinshu University. Series A, Biology 3: 15-55(1953)departmental bulletin pape

STUDIES IN THE CONCEPTS OF THE SPECIES AND THE PHYSIOLOGIC FORM IN FUSARIUM CAUSING THE BUD BLIGHT OF MULBERRY TREES

Article信州大學紀要 1(1): 175-211(1951)departmental bulletin pape

PATHOLOGICAL STUDIES OF THE "BUD BLIGHT" OF MULBERRY TREES : I. ON THE OCCURRENCE AND DEVELOPMENT OF THE DISEASE

ArticleJournal of the Shinshu University. 2: 185-227(1952)departmental bulletin pape

PATHOLOGICAL STUDIES OF THE "BUD BLIGHT" OF MULBERRY TREES : IV. PHYSIOLOGICAL CHARACTERS OF THE CAUSAL FUNGUS, GIBBERELLA LATERITIUM (NEES) SNYDER ET HANSEN

ArticleJournal of the Faculty of Textiles and Sericulture, Shinshu University. Series A, Biology 8: 17-42(1958)departmental bulletin pape

PATHOLOGICAL STUDIES OF THE "BUD BLIGHT" OF MULBERRY TREES : I. ON THE OCCURRENCE AND DEVELOPMENT OF THE DISEASE

ArticleJournal of the Faculty of Textiles and Sericulture, Shinshu University. Series A, Biology 2: 1-46(1952)departmental bulletin pape