#gallmite - Twitter Hashtag

about 2 years ago

Lime gall mite (Eriophyes tilae) on lime. In this case on Silver Weeping Lime (Tilia tomentosa petiolaris) in my #garden. #Bugs #gallmite @PippaGreenwood @The_RHS

AlanEDown's tweet photo. Lime gall mite (Eriophyes tilae) on lime.
In this case on Silver Weeping Lime (Tilia tomentosa petiolaris) in my #garden. #Bugs #gallmite
@PippaGreenwood @The_RHS https://t.co/sixwku4p7Q

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Stefan F. Wirth

@wirthstef

almost 3 years ago

A #species #complex, about #hostspecificy of a #gallmite and the precise kind of #damage, which it causes to its #host #plant. Can the mite be an agent against its #neophytic host #pest?: The gall mite #Aceria #genistae (#Acariformes, #Eriophyidae) is associated with i.a. the Scotch #broom #Cytisus #scoparius (#Fabaceae, Faboideae), which can appear as #neophyte pest for example in the #USA. According to Xiao Han, Xiaoyue Hong & Zhi-Qiang Zhang (2016) an assumed #cryptic A. genistae-complex consists in fact of only two species. #Mites from Ulex europaeus and Genista monspessulana, formerly mistaken with A. genistae, were by the authors determined as #Aceria #davidmansoni. And even a seemingly wider host range does not necessarily mean that a parasite is more generalistic than host specific. As some hosts might be a kind of emergency hosts rather than regular hosts. Although the authors above confirmed mites from #Lupinus albicaulis, Lupinus densiflorus, #Cytisus #striatus and C. scoparius as indeed A. genistae, but consider only the latter two plant hosts as part of the normal host range of the mite. It was already indicated by deformities instead of galls in L. densiflorus and even a lack of galls in L. albicaulis that these plant might not belong to the natural host range, but the authors above additionally confirmed via host specificity tests that the two Cytisus species were preferred. The mite A. genistae is of #applied interest, as its host C. scoparius appears in the US, for example in #California, as pest, having invaded Northamerica as neophyte. With its spread from its original habitats to other continents, the plant has also brought its #associated #biodiversity with it. And that includes A. genistae. C. scoparius is #native to western and central #Europe. The above authors #redescribed A. genistae in their 2015 publication and also deposited a neotype. They refer to material from C. scoparius in #France. The same publication also includes the description of the new species Aceria davidmansoni, previously sometimes confused with A. genistae. The natural distribution of this species is seemingly to me unknown, but it was first discovered in New Zealand. The damage caused by C. scoparius for example in California, is that the plant is very adaptable and prolific. It is thermophilic, tolerant of soil quality and is a quick early adopter of fallow land where its highly durable and fire-resistant seeds have the advantage of competing with and displacing native #crops. The mite A. genistae infests buds and induces the growth of an amorphous gall on which the mite feeds. Due to this obvious somehow harmful effect, the mite has already longer been discussed as a means of #pestcontrol. However, hosts are often well adapted to their parasites through coevolution and can in principle regulate at least some damage. Therefore, the question arises as to the exact consequences of stocking with the gall mite on the #vitality and reproductive success of the host plant. In the current paper by J. V. Sarratt, K. J. Perryman & P. D. Pratt (2023), the exact consequences of an infestation with A. genistae in the Scotch broom are examined using material from California (USA). The authors compared effects in heavily and lightly #galled C. scoparius. Significant differences concerned according to their paper only #canopy volume and a reduced number of #seeds per plant in heavily galled shrubs (reduction of seeds about 80% in larger plants). © #StefanFWirth Berlin 2023 Sources: 2015 paper: https://t.co/IabfJdgPJP 2016 paper: https://t.co/ZutmZbj3Z8 2023 paper: https://t.co/joUTmbisM3 Photo: Aceria genistae (Eriophyidae) - (gall), Molenhoek - the Netherlands, created by user B. Schoenmakers at https://t.co/G8bOYLS803, licensed under the Creative-Commons-Lizenz „Namensnennung 3.0 nicht portiert“. Modified by me (S. F. Wirth: Gall further enlarged from the original photo, overexposure reduced, added a slight vignette)