June, 2002 Journal of Vector Ecology 31
Leaf litter decay process and the growth performance of
Aedes albopictus larvae (Diptera: Culicidae)
Hamady Dieng, Charles Mwandawiro, Michael Boots, Ronald Morales, Tomomitsu Satho,
Nobuko Tuno, Yoshio Tsuda, and Masahiro Takagi
Department of Medical Entomology, Institute of Tropical Medicine,
1-12-4, Sakamoto, 852-8523 Nagasaki, Japan
Received 9 March 2001; Accepted 8 July 2001
ABSTRACT: Larvae of the mosquito Ae. albopictus typically develop in small aquatic sites such as tree holes
and artificial containers. Organic detritus, in particular decaying leaves, is therefore their major carbon source.
Here we demonstrate the importance of leaf characteristics, and in particular their rates of decay, in determining
the development and survivorship of larvae. We compared the effects of a rapidly decaying leaf, the maple Acer
buergerianum (Angiospermae: Aceraceae) and a slowly decaying leaf, the camphor Cinnamomum japonicum
(Angiospermae: Lauraceae), on the larval development of Ae. albopictus at different larval densities in laboratory
microcosms. Overall, the maple leaves provided a better substrate and the observed growth patterns could be
explained on the basis of a difference in nutritive and chemical contents of the two leaf types. At the highest
population density, the duration of the larval period was much shorter in maple litter microcosms. Larval mortality
gradually increased with population density in the camphor treatment. In contrast in the rapidly decaying leaf
litter microcosms, mortality remained low even as densities increased. Mean pupal size was greater in the individuals
fed on the rapidly decaying leaf litter as well as at lower density. Size is likely to be correlated with fitness in the
field. In general, rapidly decaying leaf litter will favor mosquito growth resulting in quicker development and
higher population sizes. This work emphasizes the importance of the local environment on the development of
vector mosquitoes and has important implications for control. Journal of Vector Ecology 27(1): 31-38. 2002.
Keyword Index: Leaf litter, decay, tree hole, performance, microcosm.
Mosquito population dynamics largely depend on
biological and environmental conditions (Tsuda et al.
1991). However, the interactions between the various
population parameters and the environment are so
complex that it is still problematic to fully understand
the dynamics of some vectors. In view of this complexity,
it is instructive to examine individual responses in
controlled laboratory conditions. Here we examine the
role that different types of leaf litter play in the
performance of the important vector mosquito Ae.
Mosquito larvae use allochthonous leaf detritus as
food (Walker et al. 1997) by browsing on the associated
microbial fauna (Cummins and Klug 1979, Fish and
Carpenter 1982). Aedes mosquitoes of the subgenus
Stegomyia use various aquatic sites including
phytotelmata and artificial containers (Sota et al. 1992)
that provide the same general nature of food, principally
comprised of detritus (Clements 1992). Among these,
Ae. albopictus, a known vector of dengue in Southern
Asia (Chan et al. 1971, Jumali et al. 1979), is expanding
its distribution throughout the world (Rai 1991, Reiter
1998). The adults occur in both forested and urban areas
while the larvae breed in tree holes and various artificial
containers (Makiya 1968, Eshita and Kurihara 1978,
and Hawley 1988).
In recent years, much effort has been directed
towards understanding the invasive properties of Ae.
albopictus from forested areas, where it originates, as
well as from indigenous to non-indigenous countries
(Reiter 1998). In particular, there has been a substantial
body of work looking at the response of environmental
conditions of both the larvae and the adults. Density
has been shown to have a negative effect and food level
a positive effect on immature survival, duration of
development, and size at emergence (Mori 1979, Lord
1998). Habitat food level has also been previously
documented to influence the susceptibility to parasite
32 Journal of Vector Ecology June, 2002
infection (Willis and Nasci 1994).
The internal properties of containers such as the
color (Trimble 1979) and chemical properties (Benson
et al. 1988) of their contents have been shown to be
important cues that a gravid female must consider in
oviposition site choice. High levels of decay products
are a signal of good food in quality and quantity and
are known to attract ovipositing females to tree holes
(Wilton 1968, Beehler et al. 1992, and Paradise 1999).
It is likely that there is a close relationship between
these properties and the decay process of plant materials.
Although decaying leaf detritus is the major source of
organic carbon for the container inhabitants (Kitching
1983), leaf substrate, varies widely in nutritional quality
by the associated microbial flora (Ward and Cummins
1979) and their decomposition rates (Young et al. 1997).
It seems likely, therefore, that Ae. albopictus populations
in nature are largely determined by competition for
Although a few experimental studies on Ae.
albopicus have used leaves (Sota 1993, Sunahara and
Mogi 1997), they did not focus on litter quality known
to be an important factor in the productivity of
mosquitoes (Leonard and Juliano 1995, Paradise 1999,
and Strand et al. 1999). So, there is little analysis of
the significance of the detritus type on Ae. albopictus
We report here experiments on Ae. albopictus
nutritional ecology with special reference to the quality
of decaying leaves. We examined the role of two
senescent leaves from the maple (Acer buergerianum
Miq. Angiospermae: Aceraceae) and from the
camphorous laurel (Cinnamomum japonicum Sieb. Ex
Nakai Angiospermae: Lauraceae) and density-
dependence in the development of Ae. albopictus larvae.
In this paper we demonstrate that leaf litter from these
two species have different abilities to support larval
development. These affect larval dynamics and the
differences interact with population density.
MATERIALS AND METHODS
Trees and leaves
Acer buergerianum is well-distributed deciduous
tree in urban forests, parks and along roads in Nagasaki
possessing lightly colored leaves from 4 to 8 cm long.
Cinnamomum japonicum is a laurel forest tree widely
distributed in Kyushu, used in gardening and commonly
found in urban areas. It is an evergreen species with
hard leaves having a lustrous superior surface. The fresh
leaves are highly aromatic.
Leaves of these two trees are found in a diverse
range of containers associated with different densities
of mosquito larvae, including Ae. albopictus, from May
to October in the small forest when mosquito breeding
takes place. Observations have shown that containers
under the maple tree hold higher densities of
mosquitoes, in particular Ae. albopictus, when
compared to those under the camphor tree.
We established a series of microcosms with the two
types of whole senescent leaves without petiole at
different larval densities. Microcosms consisted of a
plastic container, 18.5 cm length x 12.5 cm width x 4.5
cm deep, filled with 350 ml of tap water.
Leaves were collected in roughly equal amounts
from both trees and the ground, cleaned of debris, stored
dry, and their petioles were removed before use. In each
case 0.75g of either dried A. buergerianum or dried C.
japonicum was added to microcosms as larval food.
Five larval densities (4, 8, 16, 32 and 64) of newly
hatched Ae. albopictus (Nagasaki strain field-collected
in 1998) were added to the microcosms maintained
under 25-27 °C, 60-80 % RH and 16L : 8D.
Pupae were removed and recorded for sex and body
size. The sex of the mosquito pupae was determined by
the method of Moorefield (1951). The width of the last
abdominal segment of the pupae was used as a measure
of their body-size.
As a control to measure the changes in water
4 8 16
Loss of labile substances
Figure 1. Decay of leaves of the maple A. buergerianum and the
camphorous laurel C. japonicum liters/350 ml of water in
containers with five developing larval populations of Aedes
albopictus in laboratory microcosms. (For larval number 64, error
bars were not provided for both leaf types because only one
replicate was used. The others replicates were discarded from
the analysis of decay because of technical errors during
manipulations; same thing for larval number 32 for the maple).
June, 2002 Journal of Vector Ecology 33
quality, microcosms were established with no larvae and
the absolute pH recorded every two days during the
decay process for two weeks. At the end of the
experiments, all the remaining leaf litter was collected
from the microcosms, oven-dried (50°C, 24 hours) and
weighed. In the experimental microcosms we measured
the pH, the percentage of dry matter mass lost by decay,
pupation time, mortality and pupal body-size. Loss of
dry matter by the leaves was determined by the
difference between the initial and the final dry masses.
The pupation time corresponded to the number of days
from larval introduction into the microcosm till the day
of pupation. Larval mortality was calculated by dividing
the total number of dead larvae by the initial number of
The SYSTAT statistical software package
(Wilkinson 1996) was used to perform statistical
analysis. We used Student’s paired t-test of significance
to compare the pH of the two leaf solutions. A two-way
analysis of variance was applied to compare pupation
time, larval mortality, and pupal body-size according
to the two treatments. Tukey statistic was used for the
comparison of individual larval density effects of each
treatment on these parameters.
Both substrates were acid but the maple solution
was significantly more acid than that of the camphor
solution (maple: 5.85 ± 0.20, camphor: 6.47 ± 0.10, t =
12.72, P < 0.001). Visually the maple solution had a
darker color than the camphor solution. The loss of
labile substances was much higher in the microcosms
with the maple leaves than in those with the camphor
leaves (Figure 1). It is clear that the maple leaf decayed
more rapidly than the camphor and it is therefore likely
that the maple-microcosms have more nutritional
Both larval density and leaf species as well as their
interactions significantly affected the larval period of
4 8 16
Age at pupation (day)
4 8 16
Larval mortality (%)
F = 56.00
Figure 2. Mean pupation time (± SD) of Aedes albopictus reared at five larval populations in microcosms with the maple A.
buergerianum and the camphorous laurel C. japonicum leaves as nutritional substrates for larvae [bars of the same color and with
the same letter or number do not show a significant difference (P < 0.05) based on Tukey statistic for means comparison].
Figure 3. Mortality rates (± SD) of Aedes albopictus reared at
five larval populations in microcosms with A. buergerianum and
C. japonicum leaves as nutritional substrates [bars of the same
color and with the same letter do not show a significant difference
(P < 0.05) based on Tukey statistic for means comparison].
34 Journal of Vector Ecology June, 2002
4 8 16
4 8 16
Body size at pupation (mm)
Ae. albopictus (Table 1). Individuals reared with the
maple litter had shorter developmental periods than
those fed on the camphor (Figure 2). In both treatments,
larval period tended to increase with increasing
densities. In the maple treatment, the larval period of
the males did not differ significantly between the lower
density microcosms, but was shorter when compared
to that in the highest-density microcosm containing 64
larvae (Figure 2). The larval period of the females in
the low-density microcosms of the maple treatment had
a shorter time to pupation than that of the two highest
density microcosms (32 and 64 larvae) (Figure 2). The
pattern in the camphor treatment was similar, with both
males and females showing significantly longer
development periods at the two highest densities (Figure
2). The increased development time with larval density
is therefore a result of extended development at the
highest densities (Figure 2).
The mortality rate of Ae. albopictus during
development was consistently lower in the maple leaf
microcosms (Figure 3). In the camphor treatment,
pairwise comparisons using the Tukey test reveal that
the mortality in the highest density microcosm was
significantly different to all the others. There were no
other significant pairwise differences among lower
densities. Clearly, therefore, mortality is affected by
density in the camphor treatment leaf microcosms, but
this effect is mostly seen at high densities. The maple
treatment showed similar patterns but in contrast, there
was no significant variation of mortality between the
two highest densities (Figure 3).
The leaf species and density significantly affected
the size at pupation. There was also a significant
interaction between the leaf species and the density,
showing that density had different effects in the two
leaf treatments (Table 1). Larvae reared with the
camphor leaf litter were smaller than those produced
from the maple microcosms (Figure 4). In both types of
microcosms and for both sexes, the pupal size tended
to decrease with increasing densities (Figure 4). This
density effect tended to be stronger in the maple
microcosms as compared to camphor microcosms (Table
1, Figure 4).
The most important observation from our results
is that maple leaf litter is a more suitable substrate for
mosquito development than camphor leaf litter. The
developmental period was clearly shorter in the maple-
microcosms, especially in those with high densities. The
camphor litter produced higher mortality rates as
densities increased. The size at pupation was also
reduced in the camphor microcosms.
Within the experimental units, we showed a major effect
of both nutritional resources and density on development
time. Clearly, in the field an increased development time
will tend to result in higher cumulative mortality. With
an extended developmental period, larvae are more
exposed to possible parasites and predators as well as
Figure 4. Average width of the last abdominal segment (± SD) of Aedes albopictus pupated from microcosms where the nutritional
substrate was senescent leaves from the maple Acer buergerianum or from the camphorous laurel Cinnamomum japonicum [bars
of the same color and with the same letter do not show a significant difference (P < 0.05) based on Tukey statistic for means
June, 2002 Journal of Vector Ecology 35
an increased risk of desiccation as habitats dry up prior
to adult emergence. The increased developmental period
on the slow decaying litter will therefore lead to smaller
population sizes of mosquitoes. The smaller adult size
of mosquitoes is also likely to have an impact on the
population density of the mosquito. Size is often
correlated with fitness in the field, because it can affect
both the reproductive potential and feeding behavior of
adult mosquitoes. Small size in females can lead to fewer
eggs per batch and a slower post-emergence pre-blood
meal ovarian development (Jalil 1974, Livdahl 1984).
Larger females are suggested to have greater vector
potential, because they may be more successful at finding
a second blood meal (Nasci 1986). In Ae. albopictus
males, small size can cause delayed spermatogenesis
(Smith and Hartberg 1974).
It is interesting to note that the type of leaf detritus
had less effect on the males of Ae. albopictus than
females. Males require less energy to complete
development (Haramis 1984) probably due to the sex-
related differences in larval nutrient metabolism and
physiological roles after emergence. The different roles
of adult females and males are frequently reflected in
differences in larval development. Females need a long
developmental time in order to accumulate sufficient
nutrients for egg production.
There was clearly a relationship between the
decomposition of the leaves and the availability of
nutrients in the experimental units. A number of studies
have reported a correlation between the decomposition
pattern of leaves and their nutritional value. Rapidly
decomposing leaves are known to produce higher
nutrients concentration when compared to slowly
decomposing leaves (Kaushik and Hynes 1971) while
pH has been reported to have little effect on mosquito
larvae (MacGregor 1929). Cummins et al. (1973)
observed a higher development rate in the Tipula
populations when fed on rapidly decaying leaf litter. In
a related work, Otto (1974) also found that when alder
leaves were plentiful, there was a steady increase in the
fat content of Trichoptera larvae, but when beech leaves
were the principal food, fat content dropped. In feeding
trials, the same author further demonstrated that larvae
fed on beech leaves were 27% below; and those fed alder
leaves were 25% above the weights of the field
population. He attributed both effects to an increase of
alder leaves that were rapidly decaying. Differences in
larval development pattern have been also reported in
mosquitoes. Fish and Carpenter (1982) compared the
larval dynamics of Ae. triseriatus on beech, black oak
and maple litters and recorded that the fastest decaying
leaf, the maple, was most suitable substrate for the
development of the mosquito. Carpenter (1983) studied
TABLE 1. ANOVA test for effects of leaf-treatment and density on pupation time and pupal size of Aedes albopictus.
pupation time (day) pupal size (mm) pupation time (day) pupal size (mm)
Source variables df F-value P-value df F-value P-value df F-value P-value df F-value P-value
Leaf species* 1 36.403 < 0.000 1 98.750 < 0.000 1 101.643 < 0.000 1 138.757 < 0.000
Density** 4 65.048 < 0.000 4 43.020 < 0.000 4 131.705 < 0.000 4 60.441 < 0.000
Leaf species x Density 4 36.221 < 0.000 4 3.851 0.005 4 48.921 < 0.000 4 6.043 < 0.000
* = Camphor and Maple; ** = 4, 8, 16, 32 and 64 larvae; x = Interaction
36 Journal of Vector Ecology June, 2002
the regulation of larval populations and concluded that
slowly decomposing beech litter limited the growth and
reduced the survivorship of Ae. triseriatus.
However, decay rate may not be the single factor
that affected the growth performance and mortality
patterns observed in the present study even though Fish
and Carpenter (1982) and Carpenter (1983) have argued
this case. Walker et al. (1997) in an experiment where
leaves came from the same species of tree but of differing
quality, found that decay rate (measured as loss of matter
per unit time) could explain only about half of the
observed difference in Ae. triseriatus biomass
production. Here we have two different leaf species with
different decay rates as well as different chemical
compositions. Low ability of slowly decomposing leaf
litter can be due to high concentrations of polyphenols
which are toxic to a number of insects (Feeny 1970),
and by a high level of lignin (Kaushik and Hynes 1971).
Phytochemicals were previously documented to reduce
extracellular enzyme activity of fungi resulting in
retarded fungal growth (Suberkropp et al. 1976) that
affects their ability to cause rapid leaf decay. The leaves
of Cinnamomum sp contain chemicals that inhibit
microbes (Mau et al. 2001). It is possible that these
chemicals inhibited microbial growth and consequently
stalled larval growth in camphor microcosms. There
may have also been direct effects of chemical substances
on the camphorous laurel leaves that could have caused
the mortality observed here. Lederhouse et al. (1992)
showed that leaves of lauraceous plants including the
genera Persea and Lindera, species related to C.
japonicum were toxic to two lepidoptera caterpillars
that used these leaves as food. According to the same
author, aside from toxicity effects, some other
compounds of laurel leaves may also function as feeding
inhibitors of the caterpillar larvae. Thus, with regard
to these reports, the differences seen here between the
maple and camphor leaves are more likely due to the
difference in their ability to release labile substances
that could function as nutrients and/or larval feeding
inhibitors which may affect microbial production and
thus Ae. albopictus larvae growth. Although the extracts
of Acer sp have been reported toxic (Plumlee 1991), C.
japonicum seem to be more toxic and one wonders if it
might not have an inhibitory effect on Ae. albopictus
larvae in the present study.
Regardless of other factors involved in the overall
population dynamics in areas with different vegetation,
one may expect maple-dominated areas to support
higher densities of mosquitoes than areas where the
camphor tree predominates. Ae. triseriatus population
densities have been shown to be higher in maple habitats
compared to mixed hardwood sites (Nasci et al. 2000).
In contrast Eshita and Kurihara (1978) and Miyagi and
Toma (1978, 1980) reported that Ae. albopictus is rare
or absent in natural forests with evergreen broad-leaved
As well as providing insight into the nutritional
ecology of Ae. albopictus, this work suggests the
importance of removing vegetation from artificial
containers near residences since leaves provide resources
for the development of larvae. Careful choice of trees
planted close to inhabited areas clearly has the potential
to reduce densities of this vector mosquito. This
approach is likely to be most successful in areas where
many of the trees are planted decoratively in gardens
The authors are grateful to Dr. Pradya Somboon,
Ms. E. Urakawa for their assistance in laboratory works.
We also thank Gerry Marten and Steven A. Juliano for
their review of this manuscript and their valuable
Beehler, J., S. Lohr, and G. Defoliart. 1992. Factors
influencing oviposition in Aedes triseriatus
(Diptera : Culicidae). Great Lakes Entomol. 25:
Benson, G. L., C. S. Apperson, and W. Clay. 1988.
Factors affecting oviposition site preference by
Toxorhynchites splendens in the laboratory. J. Am.
Mosq. Contr. Assoc. 4: 20-22.
Carpenter, S. R. 1983. Resource limitation of larval
treehole mosquitoes subsisting on beech detritus.
Ecology. 64: 219-223.
Chan, Y. C., B. C. Ho, and K. L. Chan. 1971. Aedes
aegypti (L.) and Aedes albopictus (Skuse) in
Singapore city. Observations in relation to dengue
haemorrhagic fever. Bull. Wld. Hlth. Org. 44: 651-
Clements, A. N. 1992. The biology of mosquitoes. Vol.
1. Chapman and Hall, London. 509 pp.
Cummins, K. W., R. C. Petersen, F. O. Howard, J. C.
Wuycheck, and V. I. Holt. 1973. The utilization of
leaf litter by stream detritivores. Ecology 54: 336-
Cummins, K. W. and M. J. Klug. 1979. Feeding ecology
of streams invertebrates. Annu. Rev. Ecol. System.
Eshita, Y. and T. Kurihara.1978. Studies on the habitats
of Aedes albopictus Aedes riversi in the
Southwestern part of Japan. Japn. J. Sanit. Zool.
June, 2002 Journal of Vector Ecology 37
Feeny, P. 1970. Seasonal changes in oak leaf tannins
and nutrients as a cause of spring feeding by winter
moth caterpillars. Ecology 51: 565-581.
Fish, D. and S. R. Carpenter. 1982. Leaf litter and larval
mosquito dynamics in tree-hole ecosystems.
Ecology 63: 283-288.
Haramis, L. D. 1984. Aedes triseriatus: a comparison
of density in tree holes vs. discarded tires. Mosq.
News 44: 485-489.
Hawley, W. A. 1988. The biology of Aedes albopictus.
J. Am. Mosq. Contr. Assoc. (Suppl.). 1: 1-40.
Jalil, M. 1974. Observations of the fecundity of Aedes
triseriatus (Diptera: Culicidae). Entomol. Exp.
Appl. 17: 223-233.
Jumali, Suarto, D. J. Gubler, S. Nalim, S. Eram, and J.
S. Saroso. 1979. Epidemic dengue haemorrrhagic
fever in rural Indonesia III. Entomological studies.
Am. J. Trop. Med. Hyg. 28: 717-724.
Kaushik, N. K. and H. B. N. Hynes. 1971. The fate of
the dead leaves that fall into streams. Arch.
Hydrobiol. 68: 465-515.
Kitching, R. L. 1983. Community structure in water-
filled treeholes in Europe and Australia –
comparisons and speculations. In Phytotelmata:
terrestrial plants as hosts for aquatic insect
communities. (J.H. Frank and L.P. Lounibos, eds).
pp. 205-222. Plexus, Medford, NJ.
Lederhouse, R. C., P. A. Matthew, K. N. Nitao, and S.
Mark. 1992. Differential use of lauraceous hosts
by swallowtail butterflies, Papilio troilus and P.
palamedes (Papilionidae). Oikos. 63: 244-252.
Leonard, P. M. and S. A. Juliano. 1995. Effect of leaf
litter and density on fitness and population
performance of the treehole mosquito Aedes
triseriatus. Ecol. Entomol. 20: 125-136.
Livdahl, T., R. Koenekoop and S. G. Futterweit. 1984.
The complex hatching response of Aedes eggs to
larval density. Ecol. Entomology. 9: 437-442.
Lounibos, P.L., N. Naoya, and L. E. Richard. 1993.
Fitness of a treehole mosquito: influences of food
type and predation. Oikos. 66: 114-118.
Lord, C. C. 1998. Density dependence in larval Aedes
albopictus (Diptera: Culicidae). J. Med. Entomol.
MacGregor, M. E. 1929. The significance of the pH in
the development of the mosquito larvae.
Parasitology, 21: 132-157.
Makiya, K. 1968. Population dynamics of larvae
overwintering in southern Japan. Japn. J. Sanit.
Zool. 19: 223-229.
Mau, J. L., C. P. Chen, and P. C. Hsieh. 2001.
Antimicrobial effects from Chinese chive,
Cinnamon, and Corni fructus. J. Agric. Food Chem.
Miyagi, I. and T. Toma. 1978. Studies on the mosquitoes
in the Yaeyama Islands, Japan 2. Notes on the non-
anopheline mosquitoes collected at Ishigakijima,
1975-1976. Japn. J. Sanit. Zool. 29: 305-312.
Miyagi, I. and T. Toma. 1980. Ditto 5. Notes on the
mosquitoes collected in forest areas of Iriomotejima.
Japn. J. Sanit. Zool. 31: 81-91.
Moorefield, H. H. 1951. Sexual dimorphism in mosquito
pupae. Mosq. News 11: 175-177.
Mori, A. 1979. Effects of larval density and nutrition
on some immature and adults Aedes albopictus.
Trop. Med. 21: 85-103.
Nasci, R. S. 1986. The size of emerging and host-seeking
Aedes aegypti and the relation of size to blood-
feeding success in the field. J. Am. Mosq. Contr.
Assoc. 2: 61-62.
Nasci, R. S, C. G. Moore, B. J. Biggerstaff, N. A. Panella,
H. Q. Liu, N. Karabatsos, B. S. Davis, and E. S.
Brannon. 2000. La Crosse encephalitis virus
habitats associations in Nicholas County, West
Virginia. J. Med. Entomol. 37: 559-570.
Otto, C. 1974. Growth and energetics in larval
population of Potamophylax cingulatus (Steph.)
(Trichoptera) in a south Swedish stream. J. Anim.
Ecol. 43: 339-361.
Paradise, C. J and K. L. Kuhn. 1999. Interactive effects
of pH and leaf litter on a shredder, the scirtid beetle,
Helodes pulchella, inhabiting tree-holes.
Freshwater Biol. 41: 43-49.
Plumlee, K. H. 1991. Red maple toxicity in horse. Vet.
Hum. Toxicol. 33: 66-67.
Rai, K. S. 1991. Aedes albopictus in the Americas.
Annu. Rev. Entomol. 36: 459-484.
Reiter, P. 1998. Aedes albopictus and the world trade
in used tires, 1985-1995: the shape of things to
come? J. Am. Mosq. Control. Assoc. 14: 83-94.
Smith, R. P. and W. K. Hartberg. 1974. Spermatogenesis
in Aedes albopictus (Skuse). Mosq. News 34: 42-
Sota, T., M. Mogi, and E. Hayamizu. 1992. Seasonal
distribution and habitat selection by Aedes
albopictus and Aedes riversi (Diptera : Culicidae)
in Northern Kyushu, Japan. J. Med. Entomol. 29:
Sota, T. 1993. Performance of Aedes albopictus and
Aedes riversi larvae (Diptera : Culicidae) in waters
that contain tannic acid and decaying leaves: is the
treehole species better adapted to treehole water?
Ann. Entomol. Soc. Am. 86: 450-457.
Strand, M., D. A. Hermes, M. P. Ayers, M. E. Kubiske,
M. G. Kaufmann, E. D. Walker, K. S. Pregitzer,
38 Journal of Vector Ecology June, 2002
and R. W. Merritt. 1999. Effects of atmospheric
CO2, light availability, and tree species on the
quality of leaf detritus as a resource for treehole
mosquitoes. Oikos 84: 277-283.
Suberkrop, K., and M. J. Klug. 1976. Fungi and
bacteria associated with leaves during processing
in a woodland stream. Ecology 57: 707-719.
Sunahara, T. and M. Mogi. 1997. Can tortoise beat the
hare? A possible mechanism for the coexistence of
competing mosquitoes in bamboo grooves. Ecol.
Res. 12: 63-70.
Trimble, R. M. 1979. Laboratory observations on
oviposition by the predacious tree-hole mosquito
Toxorhynchites rutilus septentrionalis (Diptera:
Culicidae). Can. J. Zool. 57: 1104-1108.
Tsuda, Y., M. Takagi and Y. Wada. 1991. Preliminary
laboratory study on population growth of Aedes
albopictus. Trop. Med. 33: 41-46.
Walker, E. D. and R. W. Merritt. 1991. Behavior of
larval Aedes triseriatus (Diptera : Culicidae). J.
Med. Entomol. 28: 581-589.
Walker, E. D., M. G. Kaufmann, M. P. Ayres, M. S.
Riedel and R. W. Merritt. 1997. Effects of variation
in quality of leaf detritus on growth of the eastern
tree-hole mosquito, Aedes triseriatus (Diptera:
Culicidae). Canad. J. Zool. 75: 706-718.
Ward, G. M., and K. W. Cummins. 1979. Effects of
food quality on growth of a stream detritivore,
Paratendipes albimanus (Meigen) (Diptera:
Chironomidae). Ecology 60: 57-64.
Willis, F. S. and R.S. Nasci. 1994. Aedes albopictus
(Diptera: Culicidae) population density and
structure in southwest Louisiana. J. Med. Entomol.
Wilkinson, L. 1996. Systat 6.0 for windows: Statistics.
SPSS Inc.,751 pp.
Wilton, D. P. 1968. Oviposition site selection by the
tree hole mosquito, Aedes triseriatus (Say). J. Med.
Entomol. 5: 189-194.
Young, R., L. Kirk, and A. Huryn. 1997. Organic matter
production; utilization and transport: an ecoregion
comparison of rivers throughout Southern New
Zealand. Taeri and Rivers Program, 4th Annual