Non-Bee Insects as Visitors and Pollinators of Crops: Biology, Ecology, and Management

Abstract

Insects other than bees (i.e., non-bees) have been acknowledged as important crop pollinators, but our understanding of which crop plants they visit and how effective they are as crop pollinators is limited. To compare visitation and efficiency of crop-pollinating bees and non-bees at a global scale, we review the literature published from 1950 to 2018 concerning the visitors and pollinators of 105 global food crops that are known to benefit from animal pollinators. Of the 105 animal-pollinated crops, a significant proportion are visited by both bee and non-bee taxa ( n = 82; 77%), with a total gross domestic product (GDP) value of US$780.8 billion. For crops with a narrower range of visitors, those that favor non-bees ( n = 8) have a value of US$1.2 billion, compared to those that favor bees ( n = 15), with a value of US$19.0 billion. Limited pollinator efficiency data were available for one or more taxa in only half of the crops ( n = 61; 58%). Among the non-bees, some families were recorded visiting a wide range of crops (>12), including six families of flies (Syrphidae, Calliphoridae, Muscidae, Sarcophagidae, Tachinidae, and Bombyliidae), two beetle families (Coccinelidae and Nitidulidae), ants (Formicidae), wasps (Vespidae), and four families of moths and butterflies (Hesperiidae, Lycaenidae, Nymphalidae, and Pieridae). Among the non-bees, taxa within the dipteran families Syrphidae and Calliphoridae were the most common visitors to the most crops, but this may be an artifact of the limited data available. The diversity of species and life histories in these groups of lesser-known pollinators indicates that diet, larval requirements, and other reproductive needs will require alternative habitat management practices to bees.

Spatial Distribution of Pollinating Butterflies in Yunnan Province, Southwest China with Resource Conservation Implications

“…Family Nymphalidae contains relatively lower pollinating species (Figure 2), as most members of this family feed on decomposition liquid [8]. Although previous publications partly analysed the role of butterflies in pollination (mainly for long-tongued species in family Papilionidae, Pieridae, and Nymphalidae) [3,9], the pollen transportation efficiency of each butterfly family is still poorly understood. Even though the present research did not perform analyses of pollen transportation efficiency, the 10-year cumulative field observation by the authors of feeding-oriented flower visiting (not random perching) could provide some clues.…”

“…Although the service value of pollinating butterflies is still less understood, some studies already confirmed their role in increasing yield and quality of agricultural products [98]. Such benefits are more evident in fruit horticulture and some cash crops than food crops, as many food crops belong to family Poaceae with relatively limited attracting ability to lepidopterous pollinators [3]. In comparison, fruit trees and cash crops with more developed and colourful flowers are more frequently visited by butterflies [3], and thus benefited from their diversity.…”

“…Pollinating insects as an entity is an irreplaceable natural asset to human society, especially agriculture, through ancient to modern times [1,2]. Unfortunately to date, the only group among all pollinating insects that can be tamed and utilised is still restricted to honey bees, bumble bees, some solitary bees, and wasps (Hymenoptera) [1,3,4]. The vast majority of the remaining non-Hymenoptera pollinators, including butterflies and moths (Lepidoptera), various beetles (Coleoptera), and true flies (Diptera), are still less understood and totally dependent on natural resources [1,3,[5][6][7].…”

“…Butterflies can be categorised into two groups based on their food sources, with one group feeding on nectar from flowers (generalised nectarivores) and the other one feeding on decomposition liquid from rotten fruits, urine, feces, and even corpses [8]. The generalised nectarivore butterflies are highly-efficient pollinators [3,9] and the focus of the present research.…”

Don’t forget the flies: dipteran diversity and its consequences for floral ecology and evolution

“…Despite their numerical dominance, social bees are not the only insect pollinators, nor are they always the most efficient or important pollinators for all crop plants and their wild relatives (rev. by Rader et al 2016Rader et al , 2019. Another consequence of increased global awareness of pollinator vulnerability has been a growing appreciation for the diversity and abundance of flower-visiting flies (Diptera) and their potential as alternative pollinators (Mitra and Banerjee 2007;Orford et al 2015;Ssymank et al 2008).…”