The Gall MidgeAsphondylia borrichiae(Diptera: Cecidomyiidae): An Indigenous Example of Host-Associated Genetic Divergence in Sympatry

Manner of Apical Meristem Destruction Affects Growth, Reproduction, and Survival of Sea Oxeye Daisy

“…Borrichia frutescens has had a long-term association with galling by Asphondylia borrichiae [43], which may have exerted strong selective pressure over time to which B. frutescens is better adapted and not overly burdened. Indeed, galled ramets were slightly, but not significantly, different from intact ramets for several of the performance variables assessed in the current study.…”

“…Borrichia frutescens is the primary host plant of the gall midge Asphondylia borrichiae [33,[41][42][43]. Adult A. borrichiae are small (<3 mm long), fragile, weak-flying gall midges that live for only 2-3 days, during which their primary activity is breeding [2,[44][45][46].…”

“…With occasional exceptions, female midges appear to avoid ovipositing in flower heads [40,42], and the presence of a gall typically prevents the apical meristems from flowering [33,42,45]. Galls persist on the host plant during spring and summer for about seven to ten weeks and senesce after midge eclosion, typically resulting in the death of the galled apical meristem [33,45] [43,47] have found galling on B. frutescens to be very high (approximately 30-50% of apical meristems) and a strong positive correlation between stem number and gall count (Anthony M. Rossi, unpublished data).…”

“…Intact ramets were left unprotected from galling. However, many intact ramets were expected to be galled during the experiment [43,47] and may have severely reduced the sample size of the control group. Therefore, in addition to the first control group of 50 ramets, a second control group of 20 additional intact, unfertilized ramets was selected haphazardly and protected from galling by a mesh bag.…”

Saltbush-associated Asphondylia species (Diptera: Cecidomyiidae) in the Mediterranean Basin and their chalcidoid parasitoids (Hymenoptera: Chalcidoidea)

“…Many species are univoltine and enter extended diapause inside the galls, while others are bi-or multivoltine and present complex host associations (review in Tokuda 2012). Like the great majority of gall-inducing cecidomyiids, most Asphondylia species are considered monophagous and plant-organ specific, and some groups have apparently radiated in situ on a single plant genus (Hawkins et al 1986, Gagné & Waring 1990, Joy & Crespi 2007, Stokes et al 2012.…”