Pollination ecology of Acacia gerrardii Benth. (Fabaceae: Mimosoideae) under extremely hot-dry conditions

Abstract

Talh trees (Acacia gerrardii Benth.) are acacias that are native to the arid and semiarid Africa and west Asia. We investigated the flowering biology, pod set and flower visitors of Talh and discussed the role of these visitors in pollen transfer. The Talh trees blossomed laterally on the nodes of one-year-old twigs. Each node produced 21 flower buds seasonally. Each flower bud opened to a flower head (FH) of 60 florets. The bagged FHs podded significantly (p ⩽ 0.05) less than did the unbagged FHs. The FHs were visited by 31 insect species (25 genera, 16 families and 5 orders). The major taxa were honeybees, megachilids, butterflies, ants, beetles and thrips. Each of honeybees, megachilids and beetles showed a significant (p ⩽ 0.05) hourly pattern, while each of butterflies, ants and thrips had no hourly pattern (p > 0.05). Furthermore, some birds and mammals touched the Talh FHs. Talh trees evolved a mass flowering behavior to face pre- and post-flowering obstacles. Megachilids seemed to play the major effort of zoophily because of their relatively high numbers of individuals and species and their effective movement behavior on the FH surface. Nevertheless, honeybees and other insects and vertebrate taxa also contributed to the pollen transfer. These results greatly contribute to our understanding of the pollination ecology of acacias, especially Arabian acacias.

The beetle fauna (Insecta, Coleoptera) of the Rawdhat Khorim National Park, Central Saudi Arabia

“…The flora and fauna of these unique habitats are under constant threat due to increased anthropogenic activities ( Al-Nafie 2007 ; Al-Qarawi 2011 ). However, relatively little is known about their insect fauna (e.g., Al Dhafer and Platia 2013 , Al Dhafer et al 2016 ; Sharaf et al 2013 ; Alqarni et al 2015 ; Abdel-Dayem et al 2015 , 2016 ) that contribute to the faunal biodiversity of KSA .…”

Differential Foraging of Indigenous and Exotic Honeybee (Apis mellifera L.) Races on Nectar-Rich Flow in a Subtropical Ecosystem

“…In addition to honeybees, many flower visitors visit the A. gerrardii tree flower heads. Megachilid bees ranked first before honeybees in the zoophily of Acacia flower heads [21], and considerable yield of Acacia honey is produced by honeybee colonies, despite the hyper hot-dry weather conditions that accompany Acacia flowering [22].…”

“…This study is one element of a major research project investigating how subtropical weather conditions reflect on different key points related to bee colony performance, e.g., nectar secretion dynamics, flowering phenology, pollination ecology, the honey potential of major bee plants [20,21,25,26], the antimicrobial potential of honeys [17], associative learning and heat shock protein expression [27,28], insecticidal-induced changes in the learning of honeybees [29], and the use of geographic information systems (GIS) and remote sensing technologies to determine the optimal forage capacity [30]. The present experiment was conducted to evaluate the rates of outgoing and pollen-gathering foragers during a period of rich nectar flow.…”

Nectar secretion dynamics of Ziziphus nummularia : A melliferous species of dry land ecosystems

“…Honey bees still able to survive and produce honey under adverse harsh climates just when and where melliferous floras are present (Awad et al, 2016). Moreover, the presence of wild melliferous flora may help the conservation of pollinators under such climates (Alqarni et al, 2017).…”