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In spite of the evidence for antimicrobial and acaricidal effects in ethnobotanical reports of Callitris and Widdringtonia, the diterpene acids from Widdringtonia have never been described and no comparison to the Australian clade sister genus Callitris has been made. The critically endangered South African Clanwilliam cedar, Widdringtonia wallichii (syn. W. cedarbergensis), of the Cederberg Mountains was once prized for its enduring fragrant timbers and an essential oil that gives an aroma comparable to better known Mediterranean cedars, predominantly comprised by widdrol, cedrol, and thujopsene. In South Africa, two other ‘cedars’ are known, which are called W. nodiflora and W. schwarzii, but, until now, their chemical similarity to W. wallichii has not been investigated. Much like Widdringtonia, Callitris was once prized for its termite resistant timbers and an ‘earthy’ essential oil, but predominantly guaiol. The current study demonstrates that the essential oils were similar across all three species of Widdringtonia and two known non-volatile diterpene acids were identified in leaves: the pimaradiene sandaracopimaric acid (1) and the labdane Z-communic acid (2) with a lower yield of the E-isomer (3). Additionally, in the leaves of the three species, the structures of five new antimicrobial labdanes were assigned: 12-hydroxy-8R,17-epoxy-isocommunic acid (4), 8S-formyl-isocommunic acid (5), 8R,17-epoxy-isocommunic acid (6), 8R-17R-epoxy-E-communic acid (7), and 8R-17-epoxy-E-communic acid (8). Australian Callitris columellaris (syn. C. glaucophylla) also produced 1 and its isomer isopimaric acid, pisiferal (9), and pisiferic acid (10) from its leaves. Callitris endlicheri (Parl.) F.M.Bailey yielded isoozic acid (11) as the only major diterpene. Diterpenes 4–6, pisiferic acid (10), spathulenol, and guaiol (12) demonstrated antimicrobial and acaricidal activity.

The southern cattle tick, Rhipicephalus (Boophilus) microplus is one of the most important tick species affecting bovine wealth worldwide. Three uninterrupted generations of this species were observed under laboratory conditions (28±3 oC and 80±5% R.H.) using rabbit hosts. The average life cycle was determined as 65±8 days. Adult feeding period averaged 7.1±1.24 days. Pre-oviposition and oviposition periods averaged 4.1±1.3 days and 8.6±0.85 days, respectively. Pre-hatching periods averaged 21.03±2.99 days. Larval free-living and feeding to moulting periods averaged 3.5±0.75 days and 7.9±0.69 days, respectively. Nymphal feeding to moulting periods averaged 10.9±1.38 days. Weights of unfed and fed females averaged 1.26±0.29 mg and 120.32±45.6 mg, respectively and produced egg masses with average weights of 29.5±9.03 mg. Number of eggs per female averaged 1455.3±434.5 eggs with peak oviposition on the 3rd day. Average hatching rate was 83.5±2.94%, and the reproduction efficiency index averaged at 12.79±2.85. The conversion efficiency index averaged at 0.26±0.05 and the reproduction fitness index averaged at 10.68±2.4. Tick recovery rate averaged at 4.7%. A strong linear relationship was found between weights of engorged females and weights of egg masses (r = 0.83) and also between weights of engorged females and number of eggs laid (r = 0.82). This work aims to describe temporal and quantitative biological facts of R. (B.) microplus life cycles. Few studies have discussed R. (B.) microplus biology in quantitative terms, and these data can be useful in designing control plans or in epidemiological studies under laboratory conditions.