Part 1 The importance of blood-sucking insects. Part 2 The evolution of the blood-sucking habit: prolonged close association with vertebrates morphological pre-adaptation for piercing. Part 3 Feeding preferences of blood-sucking insects: host choice host choice and species complexes. Part 4 Location of the host: the behavioural framework of host location appetitive searching activation and orientation attraction movement between hosts. Part 5 Ingestion of the blood meal: vertebrate haemostasis insect anti-haemostatic factors probing stimulants phagostimulants mouthparts blood intake. Part 6 Managing the blood meal: midgut anatomy the blood meal gonotrophic concordance nutrition host hormones in the blood meal partitioning of resources from the blood meal autogeny. Part 7 Host - insect interactions: insect distribution on the surface of the host morphological specializations for life on the host host immune responses to insect salivary secretions behavioural defences of the host density dependent effects on feeding success. Part 8 Transmission of parasites by blood-sucking insects: transmission routes specificity in vector-parasite relationships origin of vector parasite relationships.

Biology of Blood-Sucking Insects

Multiparasite communities in animals and humans: frequency, structure and pathogenic significance.

The ability of parasites to change the behavior of infected hosts has been documented and reviewed by a number of different authors (Holmes adn Bethel, 1972; Moore, 1984a). This review attempts to ...

The population biology of parasite-induced changes in host behavior.

Bluetongue virus (BTV) has long been known to be transmitted biologically by certain species of biting midge belonging to the genus Culicoides (Latreille). Du Toit (1944) in South Africa was the first to implicate a Culicoides species in the transmission of this virus when he showed that C. imicola (pallidipennis) was able to transmit bluetongue from infected to susceptible sheep. Since that time numerous authors have confirmed his observations (Walker and Davies 1971; Braverman and Galun 1973; Braverman et al. 1981, 1985; Mellor et al. 1984a). However, although there are well over 1000 species of Culicoides in the world (Boorman 1988), only 17 have been connected with BTV and to date only six, C. variipennis, C. imicola, C. fulvus, C. actoni, C. wadai and C. nubeculosus, have been proven to transmit the virus (Table 1). This number may soon be increased to eight since on the basis of epidemiological evidence and virus isolations it is 


Table 1
Field and laboratory BTV infections of Culicoides



	
Subgenus
	
Species
	
Virus isolation
	
Laboratory infection
	
Transmission


Avaritia
	
C. actoni
	
−
	
+
	
+
	
	
C. brevipalpis
	
−
	
+
	
−
	
	
C. brevitarsis
	
+
	
+
	
−
	
	
C. fulvus
	
+
	
+
	
+
	
	
C. imicola
	
+
	
+
	
+
	
	
C. obsoletus
	
+
	
−
	
−
	
	
C. tororoensis
	
+
	
−
	
−
	
	
C. wadai
	
−
	
+
	
+
	

Culicoides
	
C. peregrinus
	
−
	
±
	
−
	

Diphaeomia
	
C. debilipalpis
	
−
	
+
	
−
	

Hoffmania
	
C. insignis
	
+
	
−
	
−
	
	
C. milnei
	
+
	
-
	
-
	
	
C. venustus
	
−
	
+
	
−
	

Monoculicoides
	
C. variipennis
	
+
	
+
	
+
	
	
C. nubeculosus
	
−
	
+
	
+
	

Oecacta
	
C. oxytoma
	
−
	
+
	
−
	

Pulicaris
	
C. impunctatus
	
−
	
±
	
−
	


likely that C. insignis and C. brevitarsis will also prove to be competent BTV vectors (Greiner et al. 1985; Standfast et al. 1985). Although some of the remaining species of Culicoides may eventually be shown to be fully competent BTV vectors most species will be refractory to infection. Why this should be is not yet entirely clear, but it is known that the mechanism or mechanisms controlling the oral infection of Culicoides with BTV operate chiefly at the level of the mid-gut wall (Jennings and Mellor 1988), a single layer of cells of epithelial origin supported by a basement lamina (Hardy et al. 1983; Megahed 1956).

The replication of bluetongue virus in Culicoides vectors.

Several recent studies have demonstrated that blood-sucking mosquitoes may preferentially choose hosts infected with malarial parasites. I developed and analyzed a simple model for the dynamics of malarial transmission that incorporates such nonrandom feeding behavior by the mosquito. The dynamic variables of interest are the infected proportions of the human host and mosquito vector populations. I considered three types of nonrandom host choice: consistent preference for the infected host at all levels of host infection; increasing preference for infected hosts as the infection level of the host increases; and a switching behavior in which the mosquito switches preference from uninfected to infected hosts as the level of host infection increases. The results were compared with previous results from models with random host choice. Both the random-choice and consistent-preference models predict either a stable uninfected state or a stable persistence of the infection. For these models, increasing consisten...

Mosquito Host Choice and the Epidemiology of Malaria

Infection, dissemination, and transmission of an arbovirus in mosquitoes are enhanced by concurrent ingestion of microfilariae. Ingestion of Rift Valley fever virus alone infected only 64 percent of female Aedes taeniorhynchus. Of these, only 5 percent of refeeding mosquitoes actually transmitted virus. In contrast, ingestion of the same amount of virus from concurrently microfilaremic (Brugia malayi) gerbils resulted in 88 percent infection and 31 percent transmission. Enhanced transmission of virus may be attributed to increased transit of virus across the midgut wall. Endemic filariasis may promote arbovirus transmission in nature.

https://science.sciencemag.org/content/sci/225/4666/1039.full.pdf

PA Rossignol

Papers

Enhanced arboviral transmission by mosquitoes that concurrently ingested microfilariae.