Visualisation of Bluetongue Virus in the Salivary Apparatus of Culicoides Biting Midges Highlights the Accessory Glands as a Primary Arboviral Infection Site

Table 1 Total salivary apparatus dissections: gland recovery efficiency

	No. of large salivary glands (sg) recovered / insect			No. of accessory glands (ag) recovered / insect (Across both sg)			Total
	2 sgs	1 sg	0 sgs	4 to 8 ags	1 to 3 ags	0 ags	Total
	72 (51.8%)	54 (38.8%)	13 (9.4%)	42^a (30.2%)	50 (36%)	47 (33.8%)
*C. sonorensis* No. of insects (%)	No. of salivary apparatus with sg but not ag			No. of salivary apparatus with ag but not sg			139
	34 (24.5%)			0
	35 (40.2%)	38 (43.7%)	14 (16.1%)	23^b (26.4%)	38 (43.7%)	26 (29.9%)
*C. nubeculosus* No. of insects (%)	No. of salivary apparatus with sg but not ag			No. of salivary apparatus with ag but not sg			87
*C. nubeculosus* No. of insects (%)	15 (17.2%)			3 (3.4%)			87

Total number of dissected Culicoides (including infected and mock-infected individuals) whose salivary apparatus and bodies were processed in this study for imaging and qRT-PCR, respectively. In total, 139 C. sonorensis and 87 C. nubeculosus were processed. The number (and percentage) of salivary apparatuses from C. sonorensis or C. nubeculosus are shown in relation to the number of large salivary glands (sg) or accessory glands (ag) remaining after dissection and immunofluorescence labelling. Salivary apparatus integrity was assessed by differential interference contrast (DIC) and fluorescence confocal microscopy
^a12 insects had at least one sg with four ags
^b7 insects had at least one sg with four ags

ISSN: 1480-9222