1.   Monday, December 10, 2001 -D0217

Forensic entomology case of two burned corpses in Thailand

Kabkaew L Sukontason1, Kom Sukontason1, Chaturong Kanchai2, and Jimmy K. Olson3. (1) Chiang Mai University, Parasitology, Faculty of Medicine, Chiang Mai, Thailand, (2) Chiang Mai University, Forensic Medicine, Faculty of Medicine, Chiang Mai, Thailand, (3) Texas A&M University, Department of Entomology, Heep Building, College Station, TX

This poster documents the first incidence of forensic entomology being used in the investigation of a human death scene involving burned corpses in Thailand. In April 2000, the charred remains of two male humans tied together with rope were discovered in a forested area 50 km from downtown Chiang Mai in northern Thailand. The extent to which these corpses were burned was Level #4 of the Crow-Glassman Scale. Specimens of insects collected from the corpses included larvae of the dipteran species Chrysomya megacephala (F.), Chrysomya rufifacies (Macquart), Chrysomya nigripes Aubertin (family: Calliphoridae), Hydrotaea (=Ophyra) spinigera Stein (family: Muscidae), Sargus sp. (family: Stratiomyidae) and four unidentified flesh fly larvae (family: Sarcophagidae). Larvae and adults of the beetle, Dermestes maculatus De Geer (Coleoptera: Dermestidae) were also included. The third-instar larvae of C. rufifacies were the oldest of the fly larvae collected; and based on their age and the temperatures that prevailed in Chiang Mai during April 2000, the minimum postmortem interval (PMI) for these corpses was ca. six days. However, the presence of the dermestid beetle larvae along with the Hydrotaea and Sargus fly larvae, all give evidence that the PMI may have been longer than six days. These particular species usually invade unburned corpses after the blow fly phase of arthropod succession is completed or nearly so (e.g., 4 months PMI in a mummified human corpse in Thailand). Burning of the corpses that were the subject of the current investigation may have altered their state to the point where these non-blow fly species of insects came to associate with the corpses earlier that what is considered to be normal. Additional research is needed to ascertain the effects of various levels of burning on the succession of arthropods subsequently coming to associate with carrion so treated in Thailand.

Species 1: Diptera Calliphoridae Chrysomya (blow fly)
Keywords: Forensic entomology, Burned corpses

2. Factors Affecting Farmers' Pest Control Methods at Ban Maesa Mai, Pongyaeng Sub district, Mae Rim District, Chiang Mai Province

Author
Mr. Supap Maneerat



ABSTRACT

The purposes of this study were to study the personal characteristic, economic and social factors of the farmers at Ban Maesa Mai and to find out the relationships between these factors and pest control method as well as the problems and recommendations.

The population studied were 120 lychee farmers at Ban Maesa, Pongyaeng Sub district, Mae Rim District, Chiang Mai. The data was collected by interviewing and was statistically analyzed by percentage, means and Chi-square.

The result revealed that 94.2 percent of the farmers at Ban Maesa Mai were male with an average age of 37.9 years old. Forty eight percent of them were uneducated, while all of them could speak Thai. An experience in growing lychee was 11.9 years. Most of them did not occupied social status and got message from more than one kind of mass media. Pest control messages was derived from neighbors. That was 27.5 percent. Forty six percent of them bought the chemicals from the shops at the district. An average agricultural area was 7 rais with an average farm income of 53,929 Baht per year while an out-farm income was 18,761 Baht per year. Their knowledge about environmental conservation was at moderately high level.

With regard to methods to prevent and eliminate the lychee pest, it was found that 100 percent of them use chemicals, 99.2 percent concealed the chemicals, 93.3 percent wore long-sleeve shirts and stayed beyond the wind when spraying, 92.5 percent applied the chemicals according to the labels, 91.7 percent sometimes decided to apply chemicals according to their experiences, 90.0 percent didn't eat or drink anything while spraying, 89.2 percent read the labels before using every time, 88.3 percent stopped spraying when there was strong wind, 88.3 percent fumigated the orchard, 85.8 percent measured chemical as advised, 44.2 percent used their hands to catch or crush insects, 30.8 percent used glue trap, 26.7 percent wrapped lychee fruit with plastic bags or nets, 14.2 percent used natural extract and 1.7 percent used the nets to trap insects.

Hypothesis testing showed that exposure to messages, receiving agricultural advice and available of pest control equipment shop were related significantly to chemical pest control at 0.05 confidential level.

Problems of the farmers in lychee orchards were destruction from scale insects and fruit worms.

Recommendation from this study was that the organization concerned should promote other pest controls such as biological control, insect trap or natural extract for move widely use in order to decrease chemical control.

3. Water lettuce
Pistia stratiotes

Water lettuce is another floating plant that often causes problems in Florida and elsewhere in the southeastern US, and in other countries.

The first biocontrol research for water lettuce took place in Australia in the early 1980s. There, researchers released a South American weevil, Neohydronomous affinis. Based on their success, work accomplished in the US resulted in the 1987 release of the weevil in Florida. The adults feed on the leaf while the larvae mine inside the leaf. Its short life cylcle of 30 days allows rapid population development. Eighteen months after release of the weevils at a site on Lake Okeechobee, Florida, the entire 75-acre mat of water lettuce was eliminated. The weevils continue to spread.

Another insect, a moth from Thailand, has been released in the US and native populations have been augmented in Thailand. This moth, Spodoptera pectinicornis (formerly Namangana pectinicornis), has a life cycle of about 35 days; only the larvae feed on the plant, but they do cause extensive damage.

4.   Abstract  http://www.cpitt.uq.edu.au/chromolaena/1/1nap.html

In Thailand, biological control of Siam weed, Chromolaena odorata (Asteraceae), was initiated in 1975 with a survey and evaluation of native natural enemies which might be of potential use as biological control agents. Only an eriophyid mite, Acalitus adoratus Keifer (Acari: Eriophyidae) was found as a potential agent for further investigation. An arctild moth, Pareuchaetes pseudoinsulata Rego Barros (Lepidoptera: Arctiidae) was introduced from Guam during 1986-87 for quarantine screening and host specificity tests. Apparently the insects released on experimental basis in 1987 failed to become established and additional releases were made in 1988. Their establishment was yet to be confirmed. It was found that most eggs obtained after four generations of laboratory rearing failed to hatch. A more detailed biological study on this arctild was apparently lacking and was thus highly needed for further exploitation in biological control of Siam weed.

5.  Banziger,H. 1988. The heaviest tear drinkers: ecology and systematics of new and unusual notodontid moths. Natural History Bulletin of the Siam Society. 36:(1):17-53
 

Abstract: Seven moths are described: Tarsolepis elephantorum sp. nov., Poncetia bovoculosugens sp. nov., P. doisuthepica sp. nov., P. huaykaeoensis sp. nov., all from Doi Suthep, Chiang Mai Province, Thailand; T. equidarum sp. nov., P. siamica sp. nov. from elsewhere in northern Thailand; and P. bhutanica sp. nov. from Bhutan and Meghalaya, India. The subspecies P. albistriga sphingoides and P. a. kanshireiensis are new synonyms of P. albistriga albistriga; P. fuscipennis comb. nov. is a new combination transferred from Ramesa. Nocturnal field research during 17 years in Thailand, western Malaysia and other countries has shown T. elephantorum, T. equidarum, T. remicauda, P. albistriga, P. bovoculosugens, P. huaykaeoensis and Pydnella rosacea to be lachryphagous: male moths suck lachrymal secretions from eyes, and/or other fluids from the body, of Asian elephant (Elephas maximus), Malayan tapir (Tapirus indicus), black rhinoceros (Diceros bicornis), 4 deer (Hyelaphus porcinus [Cervus porcinus], C. unicolor, C. dama and C. elaphus) and 2 antelope species (Boselaphus tragocamelus and Antilope cervicapra), and 5 species of domestic ungulates (horses, mules, donkeys, buffaloes and cattle). P. rosacea drank tears from the author's eye 8 times, Tarsolepis elephantorum 3 times, and many more unsuccessful attacks were experienced. This is the first report of Notodontidae feeding on human tears. Details are given of the moths' distribution, habitats, types of food, feeding behaviour, host preferences, host reactions, and seasonal abundance. Reasons for the sucking of tears by, and its restriction to, nocturnal Lepidoptera are offered.