Glossina - tsetse fly

life cycle, distribution, morphology, bionomics and habitat and medical importance

1. Glossina species (Tsetse fly) By Montasir Ghaneim Alzain M.Sc in Medical Parasitology / UOG

2. Learning objectives By the end of this lecture students should be able to: 1- Classify Tsetse flies . 2- Describe the morphology of the fly . 3- Know their life cycle, bionomics and habitat . 4- Know the medical importance of Glossina .

3. Classification of glossina (Tsetse fly) Scientific classification Kingdom: Animalia Phylum: Arthropoda Class: Insecta Order: Diptera Family: Glossinidae Genus: Glossina Species : G . Morsitans , G. Fusca and G. Palpalis groups (23 subspecies).

4. Introduction In Sudan tsetse has the local name ‘ Umm Bogeni ’ and officially in the atlas of the Republic of the Sudan ‘ El zubabah ’. Morsitans group ( Savanna ) found a cross West Africa to Central and East Africa. Palpalis group ( Riverine ) only found in West Africa. Fusca group ( Forest ) found in central , West and East Africa.

5. Descriptions of glossina spp ( Tsetsefly ) General look and the descriptions of the head: Tsetse flies are narrow-bodied yellowish to dark brown insects. At rest the wings are held over the back in a scissor-like manner . They are about 6-13.5 mm long depending on the species . T he antenna of glossina , has three segments, the third one is largest bent dorsally and tapering . Antenna has arista whish has branching hairs on the dorsal side only. The proboscis is from piercing and sucking type, it is long, held horizontally and has long palps .

6. Descriptions of glossina spp ( Tsetsefly ) Descriptions of the wings: The venation of the wing is very characteristic , especially the course of the M1+2 vein which looks like the hatchet (meat cleaver or axe shape).

7. Descriptions of glossina spp ( Tsetsefly ) larva and pupa

8. Life cycle of glossina species Glossina give birth to mature larvae ( Larviparous ). The egg matures in the ovary after which it is passed in the uterus to become fertilized by a sperm from the male to become embryo. The embryo takes four days to develop into the first instars larva . The larva feed on milk derived from the female milk (accessory) gland and undergoes three moults to become the fourth instars larva . Female deposit the larva in the ground under shade in soft soil .

9. Life cycle of glossina species Larva buries itself immediately and turns into a pupa . Pupa need 4-5 weeks to give adult . Depending on food and breeding habitat it can produce larva every 10 days .

10. Behavior and habitat of glossina Resting: dark and humid sites. Shaded places in forested areas, the lower woody parts of vegetation. Holes in the trunks of trees. Most species rest at height below 4 meter . Feeding: F eed on blood of human, animals, reptiles and birds. Diurnal insects. Attraction to the host: Carbon di -oxide . Large and dark object.

11. Medical Importance of glossina species Vector of human ( sleeping sickness ) and animal ( Nagana ) trypanosomiasis . Gambiense sleeping sickness (caused by Trypanosoma brucei gambiense ) is a chronic disease and is found mostly in West and Central Africa. Rhodesiense sleeping sickness (caused by Trypanosoma brucei rhodesiense ) is an acute disease that occurs mainly in East Africa.

12. Medical Importance of glossina species Gambiense sleeping sickness is mainly transmitted by tsetse flies belonging to the G. palpalis group. These flies attack people at places along rivers, lakeside villages and along roads bordered by vegetation. Rhodesiense sleeping sickness is transmitted by savanna species belonging to the G. morsitans group. These species normally feed on wild animals that inhabit savannas and woodlands, like domestic animals, such as cattle and goats.

13. THE END Any questions?