Insecticidal Effects of Croton urucurana Extracts and Crude Resin on Dysdercus maurus (Hemiptera: Pyrrocoridae)
Yield loss in different crops due to the attack of various classes of insect pests is a worldwide problem. Sucking type Dysdercus maurus causes damage to many crop species. Diverse plant species have been studied in order to identify the active ingredients responsible for their insecticidal activity against pests of economic importance. To verify the insecticidal activity of the stem bark and crude resin of Croton urucurana Baillon 1864 (Euphorbiaceae) against Dysdercus maurus Distant 1901 (Hemiptera: Pyrrhocoridae), the methanolic (EMeOH) extract, dichloromethane fraction (FDM), ethyl acetate fraction (FAE) and crude resin were applied topically with micro- applicator on the dorsal side of the mesothoracic region of third instar nymphs and the ventral side of adult insects and incorporated into an artificial diet. The average adult mortality of Dysdercus maurus treated topically with 0.5, 1.0 and 2.0% of the extracts mentioned above was significantly higher compared to controls. The FAE showed high insecticidal potential, having a higher mortality rate, extending the duration of the larval stages and resulting in malformed adults. Third instar nymphs fed with artificial seeds containing 1% FAE died three days after the start of the experiment, even before the molt to the next instar. For all treatments the death rate was greater for immature forms. These findings may provide a useful beginning for the development of biopesticides. Further studies will be carried out on mating, fecundity and proteolytic activity.
Received: July 29, 2011;
Accepted: October 14, 2011;
Published: December 12, 2011
Crop production is subject to a number of factors causing reduced productivity
and loss. Among them, insect pests are a major factor, affecting about 30% of
agricultural output. Application of insecticides is the control tactic most
used to mitigate the severe losses caused by insects. The reasons for this,
particularly in tropical and subtropical regions, include: good efficiency,
low cost, ease of use and lack of viable alternatives for control in warmer
regions (White and Leesch, 1995; Cooper
and Dobson, 2007). However, the indiscriminate use of insecticides can cause
reduction in populations of beneficial insects, resurgence and eruption of pests
and loss of effectiveness due to the selection of resistant populations (Guedes
and Pereira, 2008).
Given the increasing problems with resistance and impact on non-target organisms
related to the use of synthetic insecticides, there is an urgent need for the
development of safer alternatives, such as insecticidal proteins that interfere
with the digestive process (Carlini and Grossi-de-Sa, 2002;
Montesdeoca et al., 2005) and the use of substances
from the secondary metabolism of plants with insecticidal activity (Omar
et al., 2000; Simoes et al., 2002;
Medina et al., 2003; Akhtar
and Isman, 2004; Di Toto Blessing et al., 2010;
Colom et al., 2007, 2008).
The Euphorbiaceae is one of the least studied plant families and deserves special
mention for being one of the most extensive phanerogam families, composed of
about 300 genera and 7,600 species (Cronquist, 1981).
In this family, the genus Croton has economic importance due to its content
of essential oils and various biologically active substances such as terpenoids,
flavonoids and alkaloids (Peres et al., 1997,
1998; Suarez et al., 2003;
Anazetti et al., 2004; Fischer
et al., 2004). It is the second largest genus, with nearly 1,200
species distributed in tropical and subtropical regions (Webster,
1994). In Brazil there are approximately 300 registered Croton species
growing in forests, fields and savannas throughout the country.
The species Croton cajucara Benth (Euphorbiaceae) is rich in diterpenes
demonstrated to inhibit the growth of Heliothis virescens Fabr (Kubo
et al., 1991). Croton linearis Jacq. contains a diterpene
toxic to an important pest of sweet potato, Cylas formicarius elegantulus
Summers (Alexander et al., 1991). Studies
by Almeida et al. (1999) demonstrated that the
ethanolic extract of Croton tiglium Willd. can cause mortality of 99%
in Sitophilus zeamais Motsch. Similarly, the dichloromethane and
ethyl acetate fractions of Croton urucurana caused approximately 65%
mortality in larvae of Anagasta kuehniella, due to action of the phenolic
compounds catechin and gallocatechin (Silva et al.,
2009). Okokon and Nwafor (2009) reports that, the
root extract of Croton zambesicus possess effects antimalarial and Robert
et al. (2010) reports the anticoagulant effect of leaf extracts.
Asare et al. (2011) reports that Croton membranaceus
ingestion does not produce general acute toxicity. However, its creatinine kinase
lowering ability could be explored. Some compounds isolated from the bark of
Croton oblongifolius showed broad cytotoxicity on all cancer cell lines
tested (Pudhom and Sommit, 2011). The crude resin (dragons
blood) obtained from Croton urucurana has a potential antifungal effect
that can be explored for therapeutic advantage as an alternative treatment for
dermatophytosis or in conjunction with other antimycotics to allow the use of
lower doses avoiding problems such as side effects and or resistance (Gurgel
et al., 2005).
Today, it is known that some Croton species have strong insecticidal
activity and in some cases are more toxic to insects than pyrethrum, a substance
found in chrysanthemum flowers (Fazolin et al., 2005)
that is already commercialized as an insecticide in many parts of the world.
Croton is known for its toxicity to insects including some stored product
insect pests (Alexander et al., 1991; Silva
et al., 2009). Considering the potential use of Croton urucurana
this study aimed to evaluate the insecticidal action of methanolic extract,
semipurified fractions and crude resin of Croton urucurana (Baillon 1864)
(Euphorbiaceae), against the cotton stainer bug Dysdercus maurus (Distant
1901) (Hemiptera: Pyrrhocoridae), insects economically important as crop pests.
MATERIALS AND METHODS
Botanical material, crude resin, methanolic extract and semipurified fractions:
Stem bark and crude resin of C. urucurana were collected in the region
of Dourados, Mato Grosso do Sul, Brazil. The species was identified by Claudio
Conceição, Biology Department, Federal University of Mato Grosso
do Sul-UFMS, Campo Grande-MS and a sample was deposited (No. 5009) at the CGMS
Stem bark, dried at room temperature and ground, was extracted with methanol. After solvent evaporation in a rotary evaporator, a solid brown-reddish material, hereafter referred to as methanol extract (EMeOH), was obtained. Afterwards, the material was percolated through a silica gel 60 (200 g) column, using hexane, dichloromethane and ethyl acetate successively. This procedure afforded three semipurified Fractions: Hexane (FH), dichloromethane (FDM) and ethyl acetate (FAE). Crude resin was collected directly from the trunk.
Insect bioassays: A colony of Dysdercus maurus was started with 30 pairs captured in dome traps in the ITA90 cotton area at the Agronomy Department experimental field station, Federal University of Mato Grosso do Sul in the city of Dourados, MS.
The insects were reared at a medium temperature of 23°C, 75% relative humidity, with a 16 h light-8 h dark cycle. D. maurus life cycle is about 30-40 days from eggs to adult insects. Each female lays up to 100-200 eggs over seeds. The eggs hatch after 5-8 days and the insects develop through five nymphal stages in about 20-25 days.
The insects were kept in transparent plastic pots, covered with screen material,
with a 2 cm layer of autoclaved sand at the bottom. The insects were fed with
cotton seeds and had free access to water, stored in plastic flasks, located
inside the pots. The seeds were put inside the pots during the mating period
and up to first instar. From the second instar on, the insects were transferred
to a clean pot once a week and the seeds were placed over the screen material
that covered the pots (Staniscuaski et al., 2005).
Bioassay I and II: A range of concentrations (0.5, 1 and 2%) of test solutions was prepared from stock extracts and applied topically with micro- applicator on the dorsal side of mesothoracic region of third instar nymphs and the ventral side of adult insects. Groups of 20 insects, each treated with 5 μL extracts and confined in a glass jar formed one replicate and 5 μL of the solvent applied on 20 insects served as the control. All treatments were replicated five times. Post treatment nymphal mortality, nymphal duration, nature of adults emerged and adult survival were monitored.
Bioassay III: Third instar nymphs were fed on artificial seeds following
the methodology of Staniscuaski et al. (2005).
The artificial seeds contained 1% of the test extracts and evaluation of survival
was performed through the adult stage. All treatments were replicated three
times. The duration of each developmental stage was checked to assess whether
the test materials affected the development of insects.
Bioassay IV: Adults were fed on artificial seeds containing 1% of the test extracts and crud resin and survival was analyzed daily for a period of fifteen days. All treatments were replicated three times and adult survival was monitored.
Statistical analysis: The data obtained were analyzed by ANOVA or Kruskal-Wallis. A comparison of treatment means was performed using the Dunnet or Mann-Whitney test, p<0.05.
The effect of Croton urucurana methanolic extract (EMeOH), crude resin,
dichloromethane (FDM) and ethyl acetate fraction (FAE) applied topically was
assessed by determining the number of dead individuals seventy-two hours after
||Comparison of mean mortality in adult insects of Dysdercus
maurus at 72 h after topical application of methanolic extract (EMeOH),
dichloromethane (FDM), ethyl acetate fraction (FAE) and crude resin of Croton
||Duration of developmental stages of Dysdercus maurus
submitted to topical application of methanolic extract (EMeOH), dichloromethane
fraction (FDM), ethyl acetate fraction (FAE) and crude resin of Croton
urucurana, at concentrations of 1%. Results are expressed as means and
standard deviations of the time required for molting of all the insects
in each group
The average adult mortality of Dysdercus maurus treated topically with
0.5, 1.0 and 2.0% of the compounds mentioned above was significantly higher
than in the control group.
The mean percentage mortality of D. maurus increased with increase in concentration of the solutions tested, except for the crude resin. Topical application of the ethyl acetate fraction caused higher adult mortality (100%) compared with the other fractions (Table 1). The FAE fraction showed the strongest insecticidal activity.
D. maurus nymphs (third instar) were treated topically on the dorsal side of the mesothoracic region and the number of insects undergoing ecdysis in each group was counted for 15 days. All compounds significantly increased the average duration of all stages of development, except for fifth instar in the treatment with EMeOH (1%) (Table 2). The FAE fraction showed the highest insecticidal potential; it was associated with a higher mortality rate, increased duration of larval stages (Table 2) and a greater incidence of adult malformation.
In another experiment, third instar nymphs and adult insects were fed on artificial seeds containing C. urucurana methanolic extract (EMeOH), crude resin, dichloromethane (FDM) and ethyl acetate (FAE) (1%). It appears that the average rate of mortality was significantly higher for all treatments compared to control (Table 3). Third instar nymphs fed with artificial seed containing FAE 1% died three days after the start of the experiment, even before the molt to the next instar. For all treatments mortality was greater for immature forms. The adult insects, however, were susceptible to the same compounds as the immature insects (Table 3).
Figure 1 shows that the FAE fraction induced a more rapid entomotoxic effect in both third instar nymphs and adult insects, causing approximately 90% mortality in the first three days. The FDM fraction showed a mortality rate above 90% after the sixth day. The other treatments did not reach 90% mortality for immature forms.
Thus after a 5-10 day feeding period the mortality rate of insects fed on a diet containing 1% of C. urucurana methanolic extract (EMeOH), crude resin, dichloromethane (FDM) or ethyl acetate (FAE) was about threefold higher than that of the group feeding on a control diet.
||Effect on the rate of daily mortality of Dysdercus maurus,
comparing third instar nymphs and adult insects fed on artificial seeds
containing 1% methanolic extract (EMeOH), dichloromethane fraction (FDM),
ethyl acetate fraction (FAE) or crude resin of Croton urucurana
|Results are expressed as means and standard deviations of
average mortality rate in third instar nymphs and adult insects in each
group (* p<0.001)
|| Insecticidal effect of methanolic extract (EMeOH), dichloromethane
(FDM), ethyl acetate (FAE) fraction and crude resin of Croton urucurana
on Dysdercus maurus. Nymphs (third instar) (a) or adults (b) fed
on artificial seeds containing 1% of test substances\. The number of dead
insects was counted daily. Results are expressed as means and standard deviations
of five independent experiments, with N = 20
In insects fed with seeds containing FAE 1% the mortality rate was 90% after the sixth day (Fig. 1b). Adult insects fed on artificial seeds containing 1% methanolic extract (EMeOH), dichloromethane (FDM) fraction or crude resin of Croton urucurana were less susceptible to the insecticidal action of these compounds in comparison to the immature insects.
The utility of any botanical in plant protection against insect pests depends
upon its toxicity to the target organism and/or its effects on development and
reproduction or any other factor that leads to a reduction in its population.
The primary aim of this work was to investigate the insecticidal activity of
methanolic extract, crude resin and semipurified fraction of C. urucurana
on the mortality and developmental of Dysdercus maurus. The selection
of C. urucurana was based on popular information, its bactericidal activity,
chemical studies (Peres et al., 1997, 1998)
and reported insecticidal activity (Almeida et al.,
1999; Torres et al., 2008; Silva
et al., 2009).
Ventral topical application of semipurified FDM and FAE fractions caused significant
mortality to adult insects of Dysdercus maurus, especially FAE 2% which
was associated with a 100% mortality rate. This was similar to the results observed
by Silva et al. (2009), who reported that the
FAE 2% fraction caused 100% mortality in larvae of Anagasta kuehniella.
In topical application, the mean percentage mortality in D. maurus increased in a concentration dependent manner for all the substances tested. The methanolic extract (EMeOH), dichloromethane fraction (FDM), ethyl acetate fraction (FAE) and crude resin of C. urucurana were more toxic to D. maurus than to A. kuehniella.
All extracts, fractions and crude resin tested increased the average duration
of the third, fourth and fifth instars. The FAE fraction was most active, possessing
better insecticidal action both in topical application and when incorporated
into artificial diet. The use of plants that affect insect larval development
is advantageous because when the lifecycle is interrupted at this stage there
is a reduction in the insect population during the period in which plant damage
is being caused (Hernandez and Vendramim, 1996). Losses
caused by pest attack during grain storage can reach up to 10% (Obeng-Ofori
and Amiteye, 2005). In the experiment conducted with third instar nymphs
adult malformation resulted, probably because the entomotoxic substance caused
some disturbance in the metabolism of insect. It is necessary to investigate
the possible mode of action and substance responsible for the insecticidal action,
starting with the FAE fraction.
The FAE fraction when incorporated into artificial diet and fed to third instar
nymphs of D. maurus causes 100% mortality before the third day. The insecticidal
effect was observed for all material tested both in topical application and
when incorporated into artificial diet of the third instar nymphs and adults.
The average rate of mortality is higher for the third instar nymphs, probably
due to difficulty degrading the insecticides. Studies revealed distinct proteolytic
activities in the intestines of young and adult D. peruvianus (Staniscuaski
et al., 2005; Piovesan et al., 2008).
The difference in susceptibility to the compounds tested in third instar nymphs
and adults of Dysdercus maurus may be due to decreased protein concentration
in treated nymphs, as reported by Rao et al. (1999).
To understand the internal physiological changes, the authors treated nymphs
of Dysdercus koenigii with Artemisia annua oil and estimated the
haemolymph protein concentration of fifth instar nymphs and adults emerged from
them. It was observed that 3 days after treatment fifth instar nymphs had only
14.7 mg mL-1 protein concentration, compared with 24.9 mg mL-1
in control nymphs. This suggested that the treatment affected the protein level
drastically during the early nymphal development. However, as development proceeded
the difference in protein concentration between the treated and control insects
narrowed. The treated fifth instar nymphs on day 6 after treatment showed a
protein concentration of 20.8 mg mL-1 compared with 25.5 mg mL-1
in the control insects.
The adults that emerged from nymphs treated on days 3 and 6 had protein concentrations that were more or less equal to control insects, suggesting a restoration of protein level with increase in age. It appears that the early physiological effect of the treatment was on protein synthesis. Thus the toxic effect is most pronounced early in the insects development.
Larvae of Anagasta kuehniella when fed with artificial diet containing
the FDM (2%) or FAE (1%) fractions showed lower efficiency of conversion of
ingested and digested food which meant that in these diets a smaller quantity
of the food (energy) was used for biomass production by the insect. This is
possibly due to the fact that in those fractions an increased amount of metabolic
energy was used for degradation of toxins. This can be evidenced when comparing
the values of metabolic cost which were higher for larvae fed diets containing
the FDM fraction. Approximate digestibility was also greater for larvae fed
diets containing this fraction, indicating differential activity of the digestive
enzymes (Silva et al., 2009).
In the methanolic extract of Croton urucurana Baillon (Euphorbiaceae)
a number of known compounds, such as acetyl aleuritolic acid, stigmasterol,
b-sitosterol, campesterol, b-sitosterol-O-glucoside, sonderianin, catechin and
gallocatechin were isolated and identate (Peres et al.,
1997, 1998) which played a role in insecticidal
activity. According to Winkel-Shirley (2001), the condensed
tannins catechin and gallocatechin are phenolic compounds responsible for the
astringency of many fruits as well as defense against pests. They act by binding
to insect digestive proteins and serve as an important mechanism for plant defense
(Oliveira et al., 2003).
In bioassays using artificial seeds containing 1% concentrations of methanolic
extract (EMeOH), dichloromethane fraction (FDM), ethyl acetate fraction (FAE)
or crude resin of Croton urucurana, only the FAE fraction caused mortality
above 90% after the sixth day. It can be inferred that the toxic compounds present
in the diet are cumulative and that the insect is inefficient in the degradation.
Comparing the results of all the fractions, extracts and crude resin, tested
in experiments with topical application or when incorporated in the diet, it
appears there is a concentration of entomotoxic compound in the FAE fraction
that causes higher mortality in third instar nymphs and adult insects and increases
the duration of the instars. Similar results were observed in the study of Silva
et al. (2009).
Even with these favorable findings, additional toxicological studies with the
tannin catechin should be made to assess its impact, especially on non-target
species and to develop stable and convenient formulations of this potential
phytoinsecticide (Silva et al., 2004). When insecticidal
activity is detected, the active compounds are isolated, identified and subsequently
used in large scale. In the laboratory, the new insecticide can be chemically
transformed to suppress or minimize toxicity to mammals and natural enemies
(when necessary). However, the choice of method is based on the complexity of
the chemical structure of the substance and its synthesis may or may not be
technologically or economically feasible (Fazolin et
The results presented in this report suggest that insecticidal extracts of C. urucurana could be an important component of IPM (integrated pest management), due not only to their ability to control survival rate and time of development but also by resulting in malformed adults. Further studies will be carried out on mating, fecundity and proteolytic activity.
1: Akhtar, Y. and M.B. Isman, 2004. Comparative growth inhibitory and antifeedant effects of plant extracts and pure allelochemicals on four phytophagous insect species. J. Applied Entomol., 128: 32-38.
CrossRef | Direct Link |
2: Alexander, I.C., O.K. Pascoe, P. Marchand and L.A.D. Williams, 1991. An insecticidal diterpene from Croton linearis. Phytochemistry, 30: 1801-1803.
3: Colom, O.A., I. Barrachina, I.A. Mingol, M.C.G. Mas, P.M. Sanz, A. Neske and A. Bardon, 2008. Toxic effects of annonaceous acetogenins on Oncopeltus fasciatus. J. Pest Sci., 81: 85-89.
4: Colom, O.A., A. Neske, S. Popich and A. Bardon, 2007. Toxic effects of annonaceous acetogenins from Annona cherimolia (Magnoliales: Annonaceae) on Spodoptera frugiperda (Lepidoptera: Noctuidae). J. Pest Sci., 80: 63-67.
CrossRef | Direct Link |
5: Anazetti, M.C., P.S. Melo, N. Duran and M. Hauna, 2004. Dehydrocrotonin and its derivative, dimethylamide-crotonin induce apoptosis with lipid peroxidation and activation of caspases-2, -6 and -9 in human leukemic cells HL60. Toxicology, 15: 123-137.
6: Blessing, L.D.T., O.A. Colom, S. Popich, A. Neske and A. Bardon, 2010. Antifeedant and toxic effects of acetogenins from Annona montana on Spodoptera frugiperda. J. Pest Sci., 83: 307-310.
CrossRef | Direct Link |
7: Carlini, C.R. and M.F. Grossi-de-Sa, 2002. Plant toxic proteins with insecticidal properties. A review on their potentialities asbioinsecticides. Toxicon, 40: 1515-1539.
8: Cooper, J. and H. Dobson, 2007. The benefits of pesticides to mankind and the environment. Crop Prot., 26: 1337-1348.
CrossRef | Direct Link |
9: Cronquist, A., 1981. An Integrated System of Classification of Flowering Plants. Columbia University Press, New York
10: Fischer, H., T.E. Machen, J.H. Widdicombe, T.J. Carlson, S.R. King, J.W. Chow and B. Illek, 2004. A novel extract SB-300 from the stem bark latex of Croton lechleri inhibits CFTR-mediated chloride secretion in human colonic epithelial cells. J. Ethnopharmacol., 93: 351-357.
11: Asare, G.A., A. Sittie, K. Bugyei, B.A. Gyan and S. Adjei, 2011. Acute toxicity studies of Croton membranaceus root extract. J. Ethnopharmacol., 134: 938-943.
12: Guedes, R.N.C. and E.J.G. Pereira, 2008. Maize Weevil X Insecticides: Pyrethroid Resistance, Associated Fitness Costs and Mitigation and Management Implications. In: Crop Protection Research Advances, Burton, E.N. and P.V. Williams (Eds.). Nova Science Publishers, Hauppauge, NY, USA, pp: 125-150
13: Gurgel, L.A., J.J.C. Sidrim, D.T. Martins, V.C Filho and V.S. Rao, 2005. In vitro antifungal activity of dragon's blood from Croton urucurana against dermatophytes. J. Ethnopharmacol., 97: 409-412.
14: Kubo, I., Y. Asaka and K. Shibata, 1991. Insect growth inhibitory nor-diterpenes, cis-dehydrocrotonin and trans-dehydrocrotonin, from Croton cajucara. Phytochemistry, 30: 2545-2546.
CrossRef | Direct Link |
15: Medina, P., G. Smagghe, F. Budia, L. Tirry and E. Vinuela, 2003. Toxicity and absorption of azadirachtin, diflubenzuron, pyriproxyfen and tebufenozide after topical application in predatory larvae of Chrysoperla carnea (Neuroptera: Chrysopidae). Environ. Entomol., 32: 196-203.
Direct Link |
16: Montesdeoca, M., M.G. Lobo, N. Casanas, A. Carnero, P. Castanera and F. Ortego, 2005. Partial characterization of the proteolytic enzymes in the gut of the banana weevil, Cosmopolites sordidus and effects of soybean Kunitz trypsin inhibitor on larval performance. Entomol. Exp. Appl., 116: 227-236.
17: Obeng-Ofori, D. and S. Amiteye, 2005. Efficacy of mixing vegetable oils mixed with pirimiphos-methyl against the maize weevil, Sitophilus zeamais Motschulsky in stored maize. J. Stored Prod. Res., 41: 56-57.
Direct Link |
18: Okokon, J.E. and P.A. Nwafor, 2009. Antiplasmodial activity of root extract and fractions of Croton zambesicus. J. Ethnopharmacol., 121: 74-78.
CrossRef | Direct Link |
19: Oliveira, A.S., J. Xavier-Filho and M.P. Sales, 2003. Cysteine proteinases and cystatins. Braz. Arch. Biol. Technol., 46: 91-104.
20: Omar, S., M. Lalonde, M. Marcotte, M. Cook and J. Proulx et al., 2000. Insect growth-reducing and antifeedant activity in Eastern North America hardwood species and bioassay-guided isolation of active principales from Prunus serotina. Agril. Forest Entomol., 2: 253-257.
21: Peres, M.T., F.D. Monache, A.B. Cruz, M.G. Pizzolatti and R.A. Yunes, 1997. Chemical composition and antimicrobial activity of Croton urucurana Baillon (Euphorbiaceae). J. Ethnopharmacol., 56: 223-226.
22: Peres, M.T.L.P., M. Pizzolatti, R. Yunes and F.D. Monache, 1998. Clerodane diterpenes of Croton urucurana. Phytochemistry, 49: 171-174.
23: Piovesan, A.R., F. Staniscuaski, J. Marco-Salvadori, R. Real-Guerra, M.S. Defferrari and C.R. Carlini, 2008. Stage-specific gut proteinases of the cotton stainer bug Dysdercus peruvianus: Role in the release of entomotoxic peptides from Canavalia ensiformis urease. Insect Biochem. Mol. Biol., 38: 1023-1032.
24: Pudhom, K. and D. Sommit, 2011. Clerodane diterpenoids and a trisubstituted furan from Croton oblongifolius. Phytochem. Lett., 4: 147-150.
25: Rao, P.J., K.M. Kumar, S. Singh and B. Subrahmanyam, 1999. Effect of Artemisia annua oil on development and reproduction of Dysdercus koenigii F. (Hemiptera:Pyrrhocoridae). J. Applied Entomol., 1: 204-207.
26: Robert, S., C. Baccelli, P. Devel, J.M. Dogne and J. Quetin-Leclercq, 2010. Effects of leaf extracts from Croton zambesicus Muell. Arg. on hemostasis. J. Ethnopharmacol., 128: 641-648.
27: Winkel-Shirley, B., 2001. Flavonoid biosynthesis. A colorful model for genetics, biochemistry, cell biology and biotechnology. Plant Physiol., 126: 485-493.
CrossRef | Direct Link |
28: Silva, H.H., I.G. Silva, R.M. dos Santos, E.R. Filho and C.N. Elias, 2004. Larvicidal activity of tannins isolated of Magonia pubescens St. Hil. (Sapindaceae) against Aedes aegypti (Diptera, Culicidae). Rev. Soc. Bras. Med. Trop., 37: 396-399.
29: Silva, L.B., W. Silva, M.L.R. Macedo and M.T.L.P. Peres, 2009. Effects of Croton urucurana extracts and crude resin on Anagasta kuehniella (Lepidoptera: Pyralidae). Braz. Arch. Biol. Technol., 52: 653-664.
Direct Link |
30: Staniscuaski, F., C.T. Ferreira-Dasilva, F. Mulinari, M. Pires-Alves and C.R. Carlini, 2005. Insecticidal effects of canatoxin on the cotton stainer bug Dysdercus peruvianus (Hemiptera: Pyrrhocoridae). Toxicon, 45: 753-760.
CrossRef | PubMed |
31: Suarez, A.I., R.S. Compagnone, M.M. Salazar-Bookaman, S. Tillett, F.D. Monache, C. Di Giulio and G. Bruges, 2003. Antinociceptive and anti-inflammatory effects of Croton malambo bark aqueous extract. J. Ethnopharmacol., 88: 11-14.
CrossRef | PubMed |
32: Torres, M., J. Assuncao, G. Santiago, M. Andrade-Neto and E. Silveira et al., 2008. Larvicidal and nematicidal activities of the leaf essential oil of Croton regelianus. Chem. Biodivers., 5: 2724-2728.
33: Webster, G.L., 1994. Synopsis of the genera and suprageneric taxa of euphorbiaceae. Ann. Missouri Bot. Garden, 81: 33-144.
Direct Link |
34: White, N.D.G. and J.G. Leesch, 1995. Chemical Control. In: Integrated Management of Insects in Stored Products, Subramanyam, B.H. and D. Hagstrum (Eds.). Marcel Dekker, New York, pp: 287-330
35: Almeida, F.A.C., A.C. Goldfarb and J.P.G. Gouveia, 1999. Avaliacao de extratos vegetais e metodos de aplicacao no controle de Sitophilus spp. Revista Brasileira Produtos Agroindustriais, 1: 13-20.
36: Fazolin, M., J.L.V. Estrela, V. Catani, M.S. Lima and M.R. Alecio, 2005. Toxicidade do Oleo de Piper aduncum L. a Adultos de Cerotoma tingomarianus Bechyne (Coleoptera: Chrysomelidae). Neotrop. Entomol., 34: 485-489.
37: Hernandez, R.C. and J.D. Vendramim, 1996. Toxicidade de extrato aquoso de Meliaceae em Spodoptera frugiperda (Lepidoptera: Noctuidae). Manejo Integrado de Plagas, 42: 14-22.
38: Simoes, C.M.O., E.P. Schenkel, G. Gosman, J.C.P. Mello, L.A. Mentz and P.R. Petrovick, 2002. Metabolismo basico e origem dos metabolitos secundarios. Farmacognosia: Da planta ao Medicamento, UFSC., Porto Alegre, pp: 323-354.