Laboratory 9

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• Simulian spp.
• Tabanus spp.
• Gasterophilus spp.
• Lucilia, Sarcophaga and Calliphora adults
• Wing veins
• Antenna of Cyclorrapha
• Oestrus ovis
• Cuterebra
• Hypoderma
• Melophagus ovinus
• Ctenocephalides spp. (fleas)
• Trichodectes canis
• Damalina caprae
• Linognathus setosus
• Hematopinus spp.
• Phthirus pubis
• Pediculus humanus
• Review Question

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Card 8:1

Simulium spp. "Black Fly" Eggs

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Card 8:2

Simulium spp. A) Under the microscope is an early larval stage. 1) It is cylindrical 2) It has a posterior sucker-like organ armed with hooks. It is used as a holdfast to anchor the larva in fast moving streams. 3) It has an anterior pair of mouth brushes. 4) The ventral proleg is armed with hooks on its anterior end. It is used to migrate in "inchworm" fashion. B) Compare the size of this early larval stage with a later larval stage in the dish next to the microscope.

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Card 8:3

Simulium spp. PUPA A) It is enclosed in a cocoon which is spun by the salivary glands of the last larval stage. B) It is an exarate pupa, that is, it is not covered by the 3rd larval skin. (eg. Simulium, Tabanus, Culicoides). A pupa covered by the hardened 3rd larval skin is known as a coarctate pupa. (eg. Cyclorrhapa). C) It has respiratory filaments on the anterior end.

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Card 8:4

Simulium spp. A) The humpbacked appearance. B) The multisegmeted antennae. C) Short proboscis.

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Card 8:5

Tabanus Wing veins are important in identifying flies; however, you are not responsible for knowing the different wing vein patterns. But you should know the antenna types.	.
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Card 8:6

Tabanus spp. LARVA Note the fleshy tubercles on each segment.

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Card 8:7

Gasterophilus intestinalis and              G. nasalis Distinguish between the larvae using the key provided (figure #5 in lab book).	.
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Card 8:8

Gasterophilus intestinalis   Larvae attached to the mucosa of the stomach of a horse. You can see lesions where the larvae have detached. Note the rings of inflammatory thickening with eroded centers where the larvae were attached.

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Card 8:9

Gasterophilus sp. Left: egg on the hair of a horse leg. Right: bottle filled with horse hairs and attached eggs.

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Card 8:10

Gasterophilus sp. Adult

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Card 8:12

Lucilia, Sarcophaga, and Calliphora adults See lab handout.

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Card 8:13

Wing veins are important in identifying flies; however, you are not responsible for knowing the different wing vein patterns. But you should know the antenna types.

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Card 8.13A

Cyclorrhapha: Fly head (enface) Note the typical club-shaped antennae laying in the groove between the eyes.

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Card 8:14

Oestris ovis larvae - sheep nasal bot These were removed from the nasal cavities and frontal sinuses of sheep at New Bolton Center on post-mortem examination at the beginning of March. Note: 1. Shape and size 2. Large black oral hooks 3. Posterior spiracles 4. Morphology of spiracular plate 5. Bands of spines on the ventral surface 6. As the larvae matures it develops the brown bands on the dorsal surface of its segments.

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Card 8:15

Cuterebra larva This is a mature larva which would be found in a dermal pocket in the host. Note: 1. The dark color of the mature larva. 2. The larva is covered with spines. 3. Morphology of spiracular plate.

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Card 8:16

Leather damage due to Hypoderma This piece of leather shows the lesions following the emergence of Hypoderma sp. larvae from the back of a bovine. When the lesions heal, light spots which are scars form. The scars lower the price received for the hide.

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Card 8:17

Hypoderma sp. - Mature larvae
H. bovis 28 mm Barrel shaped Spiracle plates ear shaped, surface depressed, opening narrow, spiracle button small. Ventral surface of penultimate segment unarmed.	H. lineatum 25 mm Thinner, more pointed at ends Spiracle plates kidney-shaped. Surface level, opening wide, spiracle button well defined. Ventral surface of penultimate segment armed with spines

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Card 8:18

Melophagus ovinus - sheep ked (Fam: Hippoboscidae) Collected from lambs at New Bolton Center Note: 1. This is a wingless fly (order: Diptera). 2. Strong legs 3. Sac-like abdomen The adults live in the wool of sheep. The female lays mature larvae and cements them to the wool. The larvae immediately pupate. The adults irritate sheep by their bites and soil the fleece with feces and blood. Wool is damaged when the sheep scratch and rub themselves.

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Card 8:19

Flea Life-Cycle Egg - larva - pupa - adult

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Card 8:20

Ctenocephalides felis - larvae These larvae are free-living. Live larvae may have a red color from feeding on the adult flea's feces and dried blood. Note the tuft of strong bristles at the posterior end.

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Card 8:21

Ctenocephalides felis - the cat flea The cat flea, the dog flea, and the human flea can act as intermediate hosts for Dipylidium caninum. The larval stage of the flea becomes infected eating D. caninum eggs, and cystercercoids then develop within the flea. The final host (dogs, cats, man) acquire the infection by swallowing the infected adult flea. Note: 1. The head is longer (less blunt) than that of the dog flea, C. canis. 2. The first two spines on the genal ctenidium are almost the same size.

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Card 8:22

Ctenocephalides canis Note: General structure - head, thorax, abdomen and 3 pairs of legs. Presence of both genal and pronotal ctenidia (combs). Short first tooth on the genal ctenidium. The head is more rounded than that of C. felis.

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Card 8:23

Trichodectes canis- biting louse of dogs Note: General structure - Head, thorax, abdomen dorsoventrally flattened -Three pairs of legs with 1 claw at the end of each leg - Antennae extend laterally from head (Suborder Ischnocera) - Head: anterior end is broad and flat: characteristic of the biting lice

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Card 8:24

Damalinia caprae Adult on goat hair This louse belongs to the suborder Ischnocera (see the characteristics of Trichodectes canis).

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Card 8:25

Linognathus setosus - Nit (egg) Egg glued to the hair of a dog.

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Card 8:26

Linognathus sp. Sucking lice of this genus are found on cattle, goats, sheep and dog.

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Card 8:27

Haematopinus spp. - sucking louse Note: General structure - Head, thorax, abdomen dorsoventrally flattened - Three pairs of strong legs each with a claw - Antennae extend laterally from head - 5 segments - Narrow, pointed head with recessed stylets (adapted for sucking).

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Card 8:28

Phthirus pubis - crab or pubic louse of humans - a sucking louse (Anoplura). Note: 1. Head bearing antennae 2. Thorax with 3 pairs of legs. (The first pair of legs is slender compared to the others.) 3. Broad abdomen.

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Card 8:29

Pediculus humanis head or body louse of humans - a sucking louse (Anoplura) Note: 1. The body is longer than that of Phthirus pubis. 2. Head bearing antennae 3. Thorax with 3 pairs of legs 4. Oval abdomen The nymphs are smaller but have a very similar structure to the adults.

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Card 8:30

Review Question This louse was removed from a dog that had tapeworm segments in its feces. A. Identify the louse (be specific as possible). B. Could the dog have gotten the tapeworm from this louse? Click here for answer

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