Pupae transplantation to boost early colony growth in the weaver ant Oecophylla longinoda Latreille (Hymenoptera: Formicidae)

Oecophylla ants are currently used for biological control in fruit plantations in Australia, Asia and Africa and for protein production in Asia. To further improve the technology and implement it on a large scale, effective and fast production of live colonies is de¬sirable. Early colony development may be artificially boosted via the use of multiple queens (pleometrosis) and/or by adoption of foreign pupae in developing colonies. In the present experiments, we tested if multiple queens and transplantation of pupae could boost growth in young Oecophylla longinoda colonies. We found out that colonies with two queens artificially placed in the same nest, all perished due to queen fighting, suggesting that pleometrosis is not used by O. longinoda in Benin. In contrast, pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high survival rates (mean = 92%). Within the 50-day experi¬ment the total number of individuals in colonies with 50 and 100 pupae transplanted, increased with 169 and 387%, respectively, compared to colonies receiving no pupae. This increase was both due to the individuals added in the form of pupae but also due to an increased per capita brood production by the resident queen, triggered by the adopted pupae. Thus pupae transplantation may be used to shorten the time it takes to produce weaver ant colonies in ant nurseries, and may in this way facilitate the imple-mentation of weaver ant biocontrol in West Africa

Founding weaver ant queens (Oecophylla longinoda) increase production and nanitic worker size when adopting nonnestmate pupae

Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean = 76%). However, survival was significantly higher when 100 pupae were transplanted compared to transplantation of 300 pupae, indicating that queens were unable to handle 300 pupae adequately and that pupae require some amount of nursing. Nevertheless, within the 60-day experiment the transplantation of 300 pupae increased total colony size more than 10- fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce the time to produce weaver ant colonies for commercial purposes. This in turn may facilitate the implementation of the use of weaver ants.Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean = 76%). However, survival was significantly higher when 100 pupae were transplanted compared to transplantation of 300 pupae, indicating that queens were unable to handle 300 pupae adequately and that pupae require some amount of nursing. Nevertheless, within the 60-day experiment the transplantation of 300 pupae increased total colony size more than 10- fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce the time to produce weaver ant colonies for commercial purposes. This in turn may facilitate the implementation of the use of weaver ants.Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean = 76%). However, survival was significantly higher when 100 pupae were transplanted compared to transplantation of 300 pupae, indicating that queens were unable to handle 300 pupae adequately and that pupae require some amount of nursing. Nevertheless, within the 60-day experiment the transplantation of 300 pupae increased total colony size more than 10- fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce the time to produce weaver ant colonies for commercial purposes. This in turn may facilitate the implementation of the use of weaver ants.Weaver ants (Oecophylla longinoda Latreille) are used commercially to control pest insects and for protein production. In this respect fast colony growth is desirable for managed colonies. Transplantation of non-nestmate pupae to incipient colonies has been shown to boost colony growth. Our objectives were to find the maximum number of pupae a founding queen can handle, and to measure the associated colony growth. Secondly, we tested if transplantation of pupae led to production of larger nanitic workers (defined as unusually small worker ants produced by founding queens in their first batch of offspring). Forty-five fertilized queens were divided into three treatments: 0 (control), 100 or 300 non-nestmate pupae transplanted to each colony. Pupae transplantation resulted in highly increased growth rates, as pupae were readily adopted by the queens and showed high proportions of surviving (mean = 76%). However, survival was significantly higher when 100 pupae were transplanted compared to transplantation of 300 pupae, indicating that queens were unable to handle 300 pupae adequately and that pupae require some amount of nursing. Nevertheless, within the 60-day experiment the transplantation of 300 pupae increased total colony size more than 10- fold whereas 100 pupae increased the size 5.6 fold, compared to control. This increase was due not only to the individuals added in the form of pupae but also to an increased per capita brood production by the resident queen, triggered by the adopted pupae. The size of hatching pupae produced by the resident queen also increased with the number of pupae transplanted, leading to larger nanitic workers in colonies adopting pupae. In conclusion, pupae transplantation may be used to produce larger colonies with larger worker ants and may thus reduce the time to produce weaver ant colonies for commercial purposes. This in turn may facilitate the implementation of the use of weaver ants

Impact of African weaver ant nests [Oecophylla longinoda Latreille (Hymenoptera: Formicidae)] on mango [Mangifera indica L. (Sapindales: Anacardiaceae)] leaves

Oecophylla ants are appreciated for their control of pests in plantation crops. However, the ants ? nest building may have negative impacts on trees. In this study we tested the effect of ant densities and nest building on the leaf performance of mango trees. Trees were divided into three groups: trees without ants, trees with low and trees with high ant densities. Subsequently, the total number of leaves, the proportion of leaves used for nest construction, and tree growth was compared between these groups. The percentage of leaves used for nests was between 0.42-1.2 % (mean = 0.7%±0.02) and the total number of leaves and tree growth was not significantly different between trees with and without ants. Further, leaf performance was compared between shoots with and without ant nests and between leaves in or outside ant nests. The number of leaves and lost leaves per shoot, leaf size , leaf condition (withered), leaf longevity and hemipteran infection was compared between groups. In the dry season nest-shoots held more leaves than shoots without nests despite nest-shoots showed more lost leaves. Leaves in nests were smaller than other leaves, more likely to wither and more often infested with scales. However, smaller nest-leaf size was probably due to the ants ? preference for young leaves and the higher incidence of withering resulting as leaves in nests cannot fall to the ground. In conclusion, the costs associated to ant nests were low and did not affect the overall number of leaves per tree nor tree growth.Oecophylla ants are appreciated for their control of pests in plantation crops. However, the ants ? nest building may have negative impacts on trees. In this study we tested the effect of ant densities and nest building on the leaf performance of mango trees. Trees were divided into three groups: trees without ants, trees with low and trees with high ant densities. Subsequently, the total number of leaves, the proportion of leaves used for nest construction, and tree growth was compared between these groups. The percentage of leaves used for nests was between 0.42-1.2 % (mean = 0.7%±0.02) and the total number of leaves and tree growth was not significantly different between trees with and without ants. Further, leaf performance was compared between shoots with and without ant nests and between leaves in or outside ant nests. The number of leaves and lost leaves per shoot, leaf size , leaf condition (withered), leaf longevity and hemipteran infection was compared between groups. In the dry season nest-shoots held more leaves than shoots without nests despite nest-shoots showed more lost leaves. Leaves in nests were smaller than other leaves, more likely to wither and more often infested with scales. However, smaller nest-leaf size was probably due to the ants ? preference for young leaves and the higher incidence of withering resulting as leaves in nests cannot fall to the ground. In conclusion, the costs associated to ant nests were low and did not affect the overall number of leaves per tree nor tree growth

Field observational studies on circadian activity pattern of Oecophylla longinoda (Latreille) (Hymenoptera: Formicidae) in relation to abiotic factors and mango cultivars

Field observational studies on circadian activity pattern of Oecophylla longinoda (Latreille) were carried out during two consecutive years in a mango orchard of the Sudanian zone of Benin. Preliminary results show that circadian activity of weaver ants is continuous although diurnal activity is greater than nocturnalactivity. The consistency of the pattern suggests circadian internal clock regulation through light, temperature and humidity as its zeitgeber primary elements. Seasonal periodicity seems not to act on weaver ant activitybetween dry, rainy and harmattan seasons. Laboratory experiments now need to be implemented to check and complete these field results, and to screen for these three abiotic factors and others of potential relevance. Cultivars with thin foliage and modest canopies sheltered more nests than those with thick foliage and a dense canopy. This study raises practical issues on the use of biological control agents to improve weaver ant management and these are discussed

Diversity of fruit fly species (Diptera: Tephritidae) associated with citrus crops (Rutaceae) in southern Benin in 2008–2009

Fruit flies are pests of economic importance in many fruit crops. Little was known about Tephritid diversity in citrus orchards in southern Benin prior to this study. Traps baited with parapheromones were set in citrus orchards from August 2008 to August 2009 in the Atlantique, Ouémé and Zou departments to identify fruit fly species and monitor the fluctuation of their populations. Citrus fruits were also sampled during the citrus season (from August 2008 through August 2009) at two-week intervals and assessed in the laboratory for fruit fly damage. Other cultivated and wild fruits near the citrus orchards were also collected. The fruit fly detection trapping showed that Bactrocera invadens Drew Tsuruta & White followed by Dacus bivittatus(Bigot), was the most predominant species recorded in Citrus orchards. Bactrocera cucurbitae (Coquillett) was also recorded along with six species of Ceratitis. From all fruits sampled, the emerged fruit fly species wereprimarily B. invadens (98.3%), followed by B. cucurbitae, Ceratitis fasciventris (Bezzi), Ceratitis ditissima (Munro), Ceratitis anonae Graham and Dacus punctatifrons Karsch. The infestation rate was highest on Citrusreticulata Blanco (22%), followed by C. tangelo Macfad (18.7–19.7%) and Citrus sinensis Osbeck (5.3– 8.74%). These results are significant for the decision-making process for effective monitoring and managementof B. invadens in citrus orchards in southern Benin

Participatory evaluation of synthetic and botanical pesticide mixtures for cotton bollworm control

The bioefficacy of various plant extracts, namely Azadirachta indica A. Juss, Khaya senegalensis Desrousseaux (A. Jussieu) and Hyptis suavuolens (L.) Poit, either alone or in combination with half the recommended dose of synthetic pesticides, was studied with farmers to find a more sustainable strategy for the management of bollworms in cotton. A number of treatments were farmer innovations. The treatments were compared six times during the season to the application of the fully recommended dose of synthetic pesticides and to a control with no pesticide application. Applications of either the fully recommended dose of the synthetic pesticides or the combinations with a neem seed extract (6 kg/ha) were most effective in reducing bollworm incidence and damage. Both the treatments gave the highest yields of cottonseed, the latter being the most cost-effective. All the pesticides used, except neem alone, had a toxic effect on bollworm predators. This study has increased farmers' confidence in endogenous technology. The researcher's interaction among the local learning group members, who conducted the experiments, facilitated the introduction of a cost-effective alternative to the standard full-dose synthetic pesticide recommendation

Diversity of fruit fly species (Diptera: Tephritidae) associated with citrus crops (Rutaceae) in southern Benin in 2008-2009

Fruit flies are pests of economic importance in many fruit crops. Little was known about Tephritid diversity in citrus orchards in southern Benin prior to this study. Traps baited with parapheromones were set in citrus orchards from August 2008 to August 2009 in the Atlantique, Ouémé and Zou departments to identify fruit fly species and monitor the fluctuation of their populations. Citrus fruits were also sampled during the citrus season (from August 2008 through August 2009) at two-week intervals and assessed in the laboratory for fruit fly damage. Other cultivated and wild fruits near the citrus orchards were also collected. The fruit fly detection trapping showed that Bactrocerainvadens Drew Tsuruta & White followed by Dacus bivittatus (Bigot), was the most predominant species recorded in Citrus orchards.Bactrocera cucurbitae (Coquillett) was also recorded along with six species of Ceratitis. From all fruits sampled, the emerged fruit fly species were primarily B. invadens (98.3%), followed by B. cucurbitae, Ceratitis fasciventris (Bezzi), Ceratitis ditissima (Munro), Ceratitis anonae Grahamand Dacus punctatifrons Karsch. The infestation rate was highest on Citrus reticulata Blanco (22%), followed by C. tangelo Macfad (18.7–19.7%) and Citrus sinensis Osbeck (5.3–8.74%). These results are significant for the decision-making process for effective monitoring and management of B. invadens in citrus orchards in southern Benin