The Chinese mantis, Tenodera aridifolia sinensis (Saussure), is a univoltine tritrophic predator of old fields, now widespread after its introduction into North America more than a century ago. In 3 y of study of a population in eastern Virginia, we observed several unusual features in this oldfield insect: >90% of egg cases deposited in shrubs and trees, many at heights >2 m, not on goldenrods and similar herbaceous plants as previously reported. Egg cases were nonrandomly oriented (to the south) but with no significant association between compass orientation and days to hatching of young. Egg cases were randomly dispersed but least dense in patches without woody plants, the opposite of expectation for an oldfield insect. Finally, smaller egg cases yielded fewer and later-hatching young when oriented towards the south. A parsimonious explanation is that some females produce >1 egg case in eastern Virginia, with later egg cases being smaller and with fewer eggs because of reduced food intake. Furthermore, the southerly orientations of egg cases in trees may relate to more degree-days for greater metabolic efficiencies for females late in the growing season. Supporting this argument is a later study of temperature variation on 5 y old pine trees, which showed that south-facing locations at ground level, 1 m, and 2 m were significantly warmer than comparable north-facing locations, especially at 2 m.