Topic
Dolichoderus thoracicus
About: Dolichoderus thoracicus is a research topic. Over the lifetime, 27 publications have been published within this topic receiving 259 citations.
Papers
TL;DR: In mixed cocoa-coconut palm plantations in Malaysia the palm spadices provide large, stable nesting sites for Dolichoderus thoracicus (Smith) in contrast to impermanent sites on cocoa and on the ground, which benefit from the mixed system which also provides a more stable food supply from honeydew-producing Homoptera.
Abstract: In mixed cocoa-coconut palm plantations in Malaysia the palm spadices provide large, stable nesting sites for Dolichoderus thoracicus (Smith) in contrast to impermanent sites on cocoa and on the ground. D. thoracicus and the arboreal leaf-nesting Oecophylla smaragdina (Fabricius) both benefit from the mixed system which also provides a more stable food supply from honeydew-producing Homoptera. A scoring method showed that about 50–200 O. smaragdina or 200–2000 D. thoracicus on a cocoa tree can protect it effectively from Helopeltis theobromae Miller (Hemiptera: Miridae). The relatively greater efficiency of O. smaragdina as a biological control agent is associated with its actively dispersive predatory behaviour in contrast to the localized concentration of D. thoracicus workers at sites such as cocoa pods where it tends honeydew-producing Homoptera, and where it acts largely by deterring H. theobromae. Despite its biological control potential, the painfully biting O. smaragdina, unlike D. thoracicus, is normally considered unacceptable to plantation staff. Nevertheless it should be recognized as valuable in integrated pest management of cocoa pests especially where D. thoracicus is difficult to establish.
86 citations
TL;DR: Farmer-to-farmer training and mass media campaigns about the beneficial effect of D. thoracicus should be conducted to promote wider use of this ant species as a biological control agent and to reduce pesticide use in sapodilla orchards.
43 citations
TL;DR: The influence of the black cocoa ant Dolichoderus thoracicus on losses due to the mirid Helopeltis theivora Waterhouse, black pod disease, mammalian pests and mammalian pests was studied over a two-year period in two separate fields of cocoa.
Abstract: The influence of the black cocoa ant Dolichoderus thoracicus (Smith) on losses due to the mirid Helopeltis theivora Waterhouse, black pod disease (caused by Phytophthora palmivora (Peronosporales)) and mammalian pests (rats, squirrels and civet cats) was studied over a two-year period in two separate fields of cocoa. Both fields initially had high D. thoracicus activity. In each field, ant-scarce plots were created by treating these plots with insecticides; ant-abundant plots existed where the plots were left untreated. An abundance of D. thoracicus clearly had a negative effect on numbers of mirids, with respectively 380 and 2222% more nymphs and adults being recorded in the ant-scarce than in the ant-abundant plots over the two-year period. An abundance of D. thoracicus did not increase black pod incidence: on the contrary it reduced incidence of the disease in both fields. The number of rat-damaged pods in ant-scarce plots was significantly higher than in ant-abundant plots in one of the fields but no significant difference was detected in the other. Regarding number of pods lost to squirrels and civet cats, no significant difference between ant-scarce and ant-abundant plots was obtained for both fields; the losses to either of these mammalian pests were extremely low. The number of healthy ripe pods in ant-abundant plots was 40.4 and 32.1% higher than in ant-scarce plots in the two fields, these increases being ascribed to protection from H. theivora damage by D. thoracicus.
36 citations
TL;DR: The observed mutualistic relationship between the black cocoa ant Dolichoderus thoracicus and the mealybug Cataenococcus hispidus was examined and reiterated the necessity to manipulate both organisms for control of cocoa pests.
Abstract: The observed mutualistic relationship between the black cocoa ant Dolichoderus thoracicus (Smith) and the mealybug Cataenococcus hispidus (Morrison) was examined. The importance of C. hispidus to D. thoracicus as a food source was investigated by giving D. thoracicus access to C. hispidus only, to C. hispidus and other food sources, and denying access to any obvious food sources. Dolichoderus thoracicus was seen to depend on C. hispidus alone as a source of food over an eight-week period of observation without showing ill effects. The role of D. thoracicus in spreading C. hispidus was studied in an experiment consisting of combinations of D. thoracicus and C. hispidus exclusion. It was shown that D. thoracicus was responsible for carrying C. hispidus across a ‘mealybug excluder’. Data on the frequency and duration of transport of C. hispidus by D. thoracicus were obtained by direct observation for a total of 90 h over 17 days. Both adults and nymphs of C. hispidus were carried by D. thoracicus with its mandibles in a brief and erratic manner, in the general direction of the trail. Such transportation is nevertheless considered to be important in view of the large number of individuals of D. thoracicus moving along a trail. The close mutualistic relationship between D. thoracicus and C. hispidus reiterates the necessity to manipulate both organisms for control of cocoa pests.
33 citations
20 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 1 |
| 2020 | 1 |
| 2017 | 1 |
| 2016 | 1 |
| 2015 | 1 |
| 2014 | 1 |