2) Ms. Garet Clara Awuor

Invasive weed species are primary threats to modern agriculture, directly affecting crop productivity, land management, agrobiodiversity, and human health. Cynanchum acutum L. (swallow-wort) is a perennial herbaceous vine from the Asclepiadaceae family, reproducing via seeds and rhizomes. In Israel, it is native to the Golan Heights, Galilee, and northern Negev. However, it has become a local invasive species in the southern Arava, endangering both young and mature date plantations. We examined the biotic pollination of C. acutum and its role in plant reproduction via seeds and rhizomes by (i) identifying and evaluating C. acutum flower visitors during the blooming period and (ii) assessing how biotic pollination influences fruit and seed set, as well as shoot and rhizome development. We conducted a controlled experiment in a net house, comparing fruit and seed set, along with dry shoot and root biomass, between insect-pollinated and self-pollinated plants. Flies, ants, beetles, butterflies, wasps, and bees (in decreasing order) dominated floral visitation. Insect-pollinated plants produced significantly more seeds but had significantly lower shoot and root biomass compared to self-pollinated plants. Farmers could potentially delay their weeding efforts until shortly before seed dispersal, when the plant has directed much of its energy into seed production rather than rhizome growth. This approach would help limit both seed- and rhizome-based spread and limit the need for chemical herbicides and hence contribute to sustainable weed control.