Baited traps may be an alternative to conventional pesticides in the integrated crop management of chicory (Compositae) in South Africa
- Midgley, John M, Hill, Martin P, Villet, Martin H
- Authors: Midgley, John M , Hill, Martin P , Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6858 , http://hdl.handle.net/10962/d1011141 , http://dx.doi.org/10.1603/0022-0493(2008)101[99:BTMBAA]2.0.CO;2 , https://orcid.org/0000-0003-0579-5298
- Description: Chicory, Chicorium intybus L. (Compositae), is a major field crop in the Eastern Cape Province of South Africa. Several pests feed on the leaves of the plant, resulting in reduced yield. The most important of these are the noctuid moths Helicoverpa armigera (Hübner), Chrysodeixis acuta (Walker), and Trichoplusia orichalcea (F.). The use of attract-and-kill traps offers an alternative to broad-based insecticides in the control of these species. Three fields were treated with normal insecticides and three fields with yellow-baited traps. Eight additional traps were placed in each field, with half of the traps containing the insecticide 2,2-dichlorovinyl dimethyl phosphate (dichlorvos) and half without dichlorvos; and half yellow and half green. Total moth numbers and nonphytophage diversity were measured from these eight traps. Although no differences in H. armigera or T. orichalcea catches were observed between insecticide- and trap-treated fields, numbers of C. acuta and the total number of moths were significantly higher in insecticide-treated fields. Yellow traps containing dichlorvos contained more moths than yellow traps without dichlorvos, or green traps with dichlorvos, or green traps without dichlorvos; but they also contained more nonphytophagous insects. Yellow traps also enhanced the catches of thrips on card traps associated with them. These results offer an opportunity for the South African chicory industry to reduce pesticide applications and thus mitigate environmental impacts.
- Full Text:
- Date Issued: 2008
- Authors: Midgley, John M , Hill, Martin P , Villet, Martin H
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6858 , http://hdl.handle.net/10962/d1011141 , http://dx.doi.org/10.1603/0022-0493(2008)101[99:BTMBAA]2.0.CO;2 , https://orcid.org/0000-0003-0579-5298
- Description: Chicory, Chicorium intybus L. (Compositae), is a major field crop in the Eastern Cape Province of South Africa. Several pests feed on the leaves of the plant, resulting in reduced yield. The most important of these are the noctuid moths Helicoverpa armigera (Hübner), Chrysodeixis acuta (Walker), and Trichoplusia orichalcea (F.). The use of attract-and-kill traps offers an alternative to broad-based insecticides in the control of these species. Three fields were treated with normal insecticides and three fields with yellow-baited traps. Eight additional traps were placed in each field, with half of the traps containing the insecticide 2,2-dichlorovinyl dimethyl phosphate (dichlorvos) and half without dichlorvos; and half yellow and half green. Total moth numbers and nonphytophage diversity were measured from these eight traps. Although no differences in H. armigera or T. orichalcea catches were observed between insecticide- and trap-treated fields, numbers of C. acuta and the total number of moths were significantly higher in insecticide-treated fields. Yellow traps containing dichlorvos contained more moths than yellow traps without dichlorvos, or green traps with dichlorvos, or green traps without dichlorvos; but they also contained more nonphytophagous insects. Yellow traps also enhanced the catches of thrips on card traps associated with them. These results offer an opportunity for the South African chicory industry to reduce pesticide applications and thus mitigate environmental impacts.
- Full Text:
- Date Issued: 2008
Determination of species and instars of the larvae of the Afrotropical species of Thanatophilus Leach, 1817 (Coleoptera, Silphidae)
- Daniel, Claire A, Midgley, John M, Villet, Martin H
- Authors: Daniel, Claire A , Midgley, John M , Villet, Martin H
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59682 , vital:27638 , doi: 10.3897/afrinvertebr.58.12966
- Description: Thanatophilus micans and T. mutilatus have significance for forensic entomology. Their larvae are therefore described and a key is provided for identifying the larvae of Afrotropical Silphidae based on morphological characters. It is shown that seven common species of Thanatophilus can be distinguished by a 360 bp mtDNA sequence from the cytochrome oxidase I gene.
- Full Text:
- Date Issued: 2017
- Authors: Daniel, Claire A , Midgley, John M , Villet, Martin H
- Date: 2017
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59682 , vital:27638 , doi: 10.3897/afrinvertebr.58.12966
- Description: Thanatophilus micans and T. mutilatus have significance for forensic entomology. Their larvae are therefore described and a key is provided for identifying the larvae of Afrotropical Silphidae based on morphological characters. It is shown that seven common species of Thanatophilus can be distinguished by a 360 bp mtDNA sequence from the cytochrome oxidase I gene.
- Full Text:
- Date Issued: 2017
Effect of the killing method on post-mortem change in length of larvae of Thanatophilus micans (Fabricius, 1794) (Coleoptera: Silphidae) stored in 70% ethanol
- Midgley, John M, Villet, Martin H
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6857 , http://hdl.handle.net/10962/d1011140
- Description: It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable.
- Full Text:
- Date Issued: 2009
- Authors: Midgley, John M , Villet, Martin H
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6857 , http://hdl.handle.net/10962/d1011140
- Description: It is recommended that insect larvae collected for forensic purposes should be killed using the same method as was used to create existing models for rate of development. Certain killing methods have been shown to be preferable because they cause less distortion of the specimens, but these are not always practicable in a particular case, and so a method of correcting for effect of killing method is required. Larvae of all instars of Thanatophilus micans (Fabricius 1794) (Coleoptera: Silphidae) were measured and then killed by immersion in ethanol, immersion in hot water or freezing. Samples were re-measured immediately after death, then stored in excess 70% ethanol and re-measured after 1 week and again after 4 weeks. The change in length was significantly different from zero in all samples (t = -9.07022, p < 0.001). An analysis of covariance showed that instar, killing method and storage time all had a significant effect on the change in length. The results showed that T. micans larvae have a great potential for change in length during storage but that the change is not predictable, as the magnitude and sign of the change are variable.
- Full Text:
- Date Issued: 2009
Optimising design and effort for environmental surveys using dung beetles (Coleoptera: Scarabaeidae):
- Tocco, Claudia, Quinn, Danielle, Midgley, John M, Villet, Martin H
- Authors: Tocco, Claudia , Quinn, Danielle , Midgley, John M , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140670 , vital:37908 , DOI: 10.4039/tce.2016.48
- Description: In biological monitoring, deploying an effective standardised quantitative sampling method, optimised by trap design and sampling effort, is an essential consideration. To exemplify this using dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae and Aphodiinae) communities, three pitfall trap designs (un-baited (TN), baited at ground level (flat trap, TF), and baited above the trap (hanging trap, TH)), employed with varying levels of sampling effort (number of traps = 1, 2, 3… 10; number of days = 1, 2, 3), were evaluated for sampling completeness and efficiency in the Eastern Cape, South Africa. Modelling and resampling simulation approaches were used to suggest optimal sampling protocols across environmentally diverse sites. Overall, TF recovered the greatest abundance and species richness of dung beetles, but behavioural guilds showed conflicting trends: endocoprids preferred TH while paracoprids and telocoprids preferred TF. Resampling simulation of trap type and the two components of sampling effort suggested that six TF traps left for three days was most efficient in obtaining a representative sample and allowed differentiation between trap types, allowing the improved efficiency to be recognised. The effect of trap type on non-target specimens, particularly ants, was also investigated. TF and TH caught almost no by-catch, which is ethically desirable.
- Full Text:
- Date Issued: 2016
- Authors: Tocco, Claudia , Quinn, Danielle , Midgley, John M , Villet, Martin H
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140670 , vital:37908 , DOI: 10.4039/tce.2016.48
- Description: In biological monitoring, deploying an effective standardised quantitative sampling method, optimised by trap design and sampling effort, is an essential consideration. To exemplify this using dung beetle (Coleoptera: Scarabaeidae: Scarabaeinae and Aphodiinae) communities, three pitfall trap designs (un-baited (TN), baited at ground level (flat trap, TF), and baited above the trap (hanging trap, TH)), employed with varying levels of sampling effort (number of traps = 1, 2, 3… 10; number of days = 1, 2, 3), were evaluated for sampling completeness and efficiency in the Eastern Cape, South Africa. Modelling and resampling simulation approaches were used to suggest optimal sampling protocols across environmentally diverse sites. Overall, TF recovered the greatest abundance and species richness of dung beetles, but behavioural guilds showed conflicting trends: endocoprids preferred TH while paracoprids and telocoprids preferred TF. Resampling simulation of trap type and the two components of sampling effort suggested that six TF traps left for three days was most efficient in obtaining a representative sample and allowed differentiation between trap types, allowing the improved efficiency to be recognised. The effect of trap type on non-target specimens, particularly ants, was also investigated. TF and TH caught almost no by-catch, which is ethically desirable.
- Full Text:
- Date Issued: 2016
The distribution, habitat, diet and forensic significance of the scarab Frankenbergerius forcipatus (Harold, 1881) (Coleoptera : Scarabaeidae)
- Midgley, John M, Collett, I J, Villet, Martin H
- Authors: Midgley, John M , Collett, I J , Villet, Martin H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6842 , http://hdl.handle.net/10962/d1010992
- Description: Records of African beetles feeding on carrion are scattered and incomplete, but important to forensic entomology. Thirty-three specimens of Frankenbergerius forcipatus (Harold, 1881) were found on carrionnear Grahamstown, Eastern Cape, South Africa, providing new insight into the distribution (hills and mountains), habitat (fynbos and forest), biology (generalist on decaying material) and forensic significance (wet-decay, late opportunist) of the species.
- Full Text:
- Date Issued: 2012
- Authors: Midgley, John M , Collett, I J , Villet, Martin H
- Date: 2012
- Language: English
- Type: Article
- Identifier: vital:6842 , http://hdl.handle.net/10962/d1010992
- Description: Records of African beetles feeding on carrion are scattered and incomplete, but important to forensic entomology. Thirty-three specimens of Frankenbergerius forcipatus (Harold, 1881) were found on carrionnear Grahamstown, Eastern Cape, South Africa, providing new insight into the distribution (hills and mountains), habitat (fynbos and forest), biology (generalist on decaying material) and forensic significance (wet-decay, late opportunist) of the species.
- Full Text:
- Date Issued: 2012
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