Abstract
Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (n = 30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42°C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27°C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27°C had the highest overall mean hatching count. During early incubation periods, eggs held at 33°C had hatching counts comparable to 22 and 27°C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42°C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30°C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.
| Original language | English |
|---|---|
| Pages (from-to) | 124-130 |
| Number of pages | 7 |
| Journal | Journal of the American Mosquito Control Association |
| Volume | 23 |
| Issue number | 2 |
| DOIs | |
| State | Published - Jun 1 2007 |
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Keywords
- Anopheles gambiae
- Eggs
- Hatching
- Temperature
- Time period
ASJC Scopus subject areas
- Insect Science
Cite this
Constant temperature and time period effects on Anopheles gambiae egg hatching. / Impoinvil, Daniel E.; Cardenas, Gabriel A.; Gihture, John I.; Mbogo, Charles M.; Beier, John C.
In: Journal of the American Mosquito Control Association, Vol. 23, No. 2, 01.06.2007, p. 124-130.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Constant temperature and time period effects on Anopheles gambiae egg hatching
AU - Impoinvil, Daniel E.
AU - Cardenas, Gabriel A.
AU - Gihture, John I.
AU - Mbogo, Charles M.
AU - Beier, John C
PY - 2007/6/1
Y1 - 2007/6/1
N2 - Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (n = 30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42°C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27°C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27°C had the highest overall mean hatching count. During early incubation periods, eggs held at 33°C had hatching counts comparable to 22 and 27°C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42°C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30°C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.
AB - Anopheles gambiae Giles sensu stricto (Diptera: Culicidae) egg development and its relation to environmental parameters is an understudied aspect of vector biology. Although several studies have illustrated the dramatic effects of temperature on egg development, egg hatching dynamics remain unclear. The objective of this study was to expose An. gambiae eggs to various temperatures for different lengths of time and determine the impact on egg development and hatching count. Batches of mosquito eggs (n = 30 eggs/replicate) were incubated under moist conditions at temperatures of 12, 22, 27, 33, and 42°C for intervals of 1, 3, 7, and 10 days. After that, they were flooded with distilled water at 27°C, and hatching counts were observed for up to 7 days. Mosquito eggs held at 22 and 27°C had the highest overall mean hatching count. During early incubation periods, eggs held at 33°C had hatching counts comparable to 22 and 27°C, but counts decreased drastically during later incubation periods. Temperatures of 12 and 42°C reduced mosquito egg viability, because few eggs hatched in these temperature regimes. Other experiments revealed that during early embryonic development, temperature had a major effect on the developing embryo, while later in embryonic development it had no dramatic effect. Microscopic observation of the An. gambiae embryo showed that extreme low and high temperatures affected the normal development of the embryo. A regression model was developed to describe the effect of incubation temperature and incubation period on egg hatching counts, which demonstrated that the optimum temperature for egg hatching ranges from 24 to 30°C, irrespective of incubation period. The interaction between temperature and time period may have implications for dry-season survival and climate-based models of malaria risk.
KW - Anopheles gambiae
KW - Eggs
KW - Hatching
KW - Temperature
KW - Time period
UR - http://www.scopus.com/inward/record.url?scp=34548015440&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34548015440&partnerID=8YFLogxK
U2 - 10.2987/8756-971X(2007)23[124:CTATPE]2.0.CO;2
DO - 10.2987/8756-971X(2007)23[124:CTATPE]2.0.CO;2
M3 - Article
C2 - 17847843
AN - SCOPUS:34548015440
VL - 23
SP - 124
EP - 130
JO - Journal of the American Mosquito Control Association
JF - Journal of the American Mosquito Control Association
SN - 8756-971X
IS - 2
ER -