The name does double duty: Jaradgava is both the MIDDLE of the three great mārgas and the third vīthī within it (Matsya 124.57). Bṛhat Saṃhitā 9.3ab, jāradgavyāṃ śravaṇāt tribhaṃ, gives the triad beginning at Śravaṇa — Śravaṇa, Dhaniṣṭhā, Śatabhiṣaj — an EXACT match with the Matsya. (BS 9.1's sequential list, which Varāhamihira attributes to others, would instead put Viśākhā/Anurādhā/Jyeṣṭhā here.) Note vāruṇa here is the asterism whose deity is Varuṇa, i.e. Śatabhiṣaj.
जरद्गव / जारद्गवी Jaradgava / Jāradgavī
the Old-Ox road · — · Aquila/Delphinus/Aquarius (Śravaṇa, Dhaniṣṭhā, Vāruṇa = Śatabhiṣaj)
Attestations
Transcribed from the Devanagari OCR of the printed edition at shloka_source_url (Achyuta Nand Jha ed., vol. 1) and checked word-for-word against two further independent scans of two different printed editions of the same commentary — Krishna Chandra Dvivedi's (https://archive.org/download/brihatsamhitawithbhattotpalavivrittipartidr.krishnachandradvivedi/Brihat%20Samhita%20%20with%20Bhattotpala%20Vivritti%20Part%20I%20-%20Dr.%20Krishna%20Chandra%20Dvivedi_djvu.txt) and A.V. Tripathi's (https://archive.org/download/JiUm_brihat-samhita-part-1-of-varaha-mihira-by-avadh-bihari-tripathi-saraswati-bhavan-granthamala/Brihat%20Samhita%20Part%201%20of%20Varaha%20Mihira%20by%20Avadh%20Bihari%20Tripathi%20-%20Saraswati%20Bhavan%20Granthamala_djvu.txt). Only glyph-level OCR artifacts that all three scans show to be artifacts (e.g. OCR रद्वव for रद्गव, श्व for श्च) have been normalised; every substantive reading is as scanned, and the two places where the scans genuinely differ are flagged in identification_notes.
FIVE INDEPENDENT SCHEMES, four of them pre-Varāhamihira, are set side by side by Utpala in ch. 9 — this is the single densest surviving witness to the vīthī system, and the database's vīthī entries hitherto rest on the Purāṇas alone. (a) DEVALA and others: nine triads straight from Aśvinī, Nāgā to Dahanā. (b) KĀŚYAPA: the same triads, given asterism by asterism. (c) VARĀHAMIHIRA'S OWN (BS 9.2–3), which starts the Nāgā with Svātī instead of Aśvinī and gives the Go-vīthī four asterisms and the Dahanā two. (d) PARĀŚARA, differing again (Airāvatī four, Vṛṣabhā two, Mṛga-vīthī two, Ājī = Anurādhā/Viśākhā/Jyeṣṭhā, Vaiśvānarī = Mūla + the two Āṣāḍhās). (e) GARGA, close to Varāhamihira. Plus (f) the SAMĀSA-SAṂHITĀ, Varāhamihira's own lost epitome, agreeing with (c). Utpala explicitly notes the clash — 'atra varāhamihireṇa saha bhedaḥ', 'here there is a difference with Varāhamihira' — and Varāhamihira himself refuses to adjudicate at 9.7. Varāhamihira, Parāśara, Garga and the Samāsa-saṃhitā all make the Jāradgavī the triad from ŚRAVAṆA (Śravaṇa, Dhaniṣṭhā, Śatabhiṣaj); Devala and Kāśyapa make it the triad from VIŚĀKHĀ. As with the mārga-names, note that in the Purāṇas Jaradgava is the middle MĀRGA, whereas in every authority Utpala cites it is only one vīthī and the middle mārga has no separate name (Utpala's mārga-trio is Vāta, Vyāḍa, Vaiśvānara).