The distribution, habitat, diet and forensic significance of the scarab Frankenbergerius forcipatus (Harold, 1881) (Coleoptera : Scarabaeidae)
- Midgley, John M, Collett, Isabel J, Villet, Martin H
- Authors: Midgley, John M , Collett, Isabel 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:
- Authors: Midgley, John M , Collett, Isabel 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.
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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:
- 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.
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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:
- 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.
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