Blackflies & Others

Question 1

Vector of Loa loa

Answer 1

Chrysops - Family Tabanidae

Question 2

Simulium Genus

Answer 2

Blackflies

Question 3

Blackfly Features

Answer 3

Small (1.5 – 4 mm long
Hump-backed
Large clear wings
Short cigar-shaped antennae

Question 4

Male Blackfly

Answer 4

Eyes meet at the top of the head

Two types of ocelli, with larger ocelli at the top of the eye

Question 5

Blackfly Antennae

Answer 5

Short, stout and distinctly segmented
Cigar shaped
11 near identical segments and lack long hairs

Question 6

Blackfly Mouthparts

Answer 6

Teeth on the labrum stretch the skin, while the rasp-like action of the laciniae (maxillae) and mandibles cut through the skin

Question 7

Blackfly Wings

Answer 7

Short and wide
Do not have scales or prominent hairs
Only the leading veins (costa, subcosta, R1 and Rs) are well developed
Closed, scissorlike, over the body at rest

Question 8

Simulium damnosum Complex

Answer 8

30+ sibling species

6 are vectors of onchocerciasis

Question 9

Simulium damnosum Characteristic Features

Answer 9

Broad fore tarsi with prominent
bristles
Pale band on the first tarsal segment of the hind leg

Question 10

Simulium neavei

Answer 10

Species complex that has an intimate relationship with species of freshwater crabs/mayfly nymphs
Vector of Onchocerciasis in Uganda and the DRC

Question 11

Blackfly Eggs

Answer 11

Asymmetric, roughly triangular and between 0.1 – 0.4 mm long
Brown or black
Females lay between 150 – 800 eggs in sticky masses or strings
Hatch in 1 – 4 days

Question 12

Blackfly Larvae

Answer 12

Between 4–12 mm long
Hourglass shape
On the head are two large feeding organs called cephalic fans act as filters
Single proleg in the middle of ventral thorax

Question 13

Blackfly Pupa

Answer 13

Mature larva weaves slipper-shaped cocoon using silk from modified salivary glands
Moults into the pupa
A pair of filamentous structures called the respiratory gills arise from the dorsal thorax

Question 14

Tabanidae Antennae

Answer 14

Tabanus has short, stocky and
curved antennae
Chrysops has long spear-like antennae
Haematopota has an antennal shape that falls between the two

Question 15

Horsefiles (Tabanus Genus)

Answer 15

Medium to large flies that vary from 10 – 30 mm in length
Wings are often clear but may have dark markings
Antennae are short and stout and the pedicel and flagellum have distinct projections dorsally
Flagellum has four small subdivisions and curves upwards

Question 16

Tabanus Male and Females

Answer 16

Eyes of male are holoptic, they
come together at the top of the head
Female eyes are separate

Question 17

Tabanus Mouthparts

Answer 17

Large biting mouthparts
Labium protects the feeding stylets and is drawn back before onset of feeding
Mandibles used to cut open the skin

Question 18

Tabanus Wings

Answer 18

Clear wing with well defined veins
Wing venation of two submarginal cells, five posterior cells and a completely enclosed
discal cell
Discal cell: centrally located and crudely hexagonal in shape
Second submarginal cell usually spans the wing tip

Question 19

Deerflies (Chrysops Genus)

Answer 19

Medium sized flies about 6 – 12 mm
in length
Antennae are long and spear-like
Wing has one or two transverse bands of dark shading
Abdomen is typically dark with orange or yellow patches or bands
Hind tibae has apical spurs

Question 20

Chrysops Wings

Answer 20

Typically have a broad, brown median band

In some species the wings have two median brown bands and in others the entire distal half of the wing is pigmented

Question 21

Chrysops Antennae

Answer 21

Pedicel is long and cylindrical and lacks

any projection. The flagellum has four small subdivisions

Question 22

Clegs (Haematopota Genus)

Answer 22

Medium to large flies between 8–25 mm long
Body is typically dark grey
Wings are folded roof-like over the body at rest
Wing membrane is dusty grey with a mottled pattern
Antennae are similar to Tabanus but longer

Question 23

Haematopota Wings

Answer 23

Resting position is key - roof-like

Wing membrane is dusty grey with a mottled pattern

Question 24

Haematopota Antennae

Answer 24

The flagellum is straight, not curved and has no dorsal projection
Flagellum also has only three subdivisions

Question 25

Biting Midges (Ceratopogonidae Family)

Answer 25

Antenna with 14 visible segments
Male antennae are plumose
Female mouthparts are short and adapted for piercing and sucking
Legs are short and stout
Wings have a fork in the median vein and two radial cells
Wings are folded scissor-like over the body at rest

Question 26

Culicoides Genus

Answer 26

Very small, only 1 – 2.5 mm long
Prominent eyes, short 5-segmented palps and long filamentous antennae
Biting mouthparts are small and inconspicuous, and hang down from the head
Wing has a pattern of light and dark markings

Question 27

Male Culicoides

Answer 27

Plumose antennae and an abdomen that ends in a pair of conspicuous claspers
Mouthparts are not as highly adapted

Question 28

Female Culicoides

Answer 28

Larger and their abdomens
are more rounded
Antennae are not plumose
Distal five segments of the antenna are
elongated

Question 29

Culicoides Mouthparts

Answer 29

Similar to blackflies

Maxillary palps consist of five segments, the third segment of which is enlarged and bears sensory pits

Question 30

Culicoides Humeral Pits

Answer 30

Two depressions located on the dorsal surface of the anterior part of the thoraxare
Characteristic feature of Culicoides midges

Question 31

Culicoides Wings

Answer 31

Two radial cells

Markings: the first and second costal spots

Question 32

Culicoides Larva

Answer 32

Worm-like, whitish and about 3 – 6 mm long
Small, conical shaped head and 12 body segments
Last segment terminates in a pair of four-lobed retractile papillae (difficult to see)

Question 33

Culicoides Pupa

Answer 33

2 – 4 mm long
Pair of respiratory trumpets on the cephalothorax
Abdominal segments bear small but conspicuous tubercles
Last abdominal segment bears a prominent pair of hornlike processes