Including irrigation in niche modelling of the invasive wasp Vespula germanica (Fabricius) improves model fit to predict potential for further spread

Abstract

The European wasp, Vespula germanica (Fabricius) (Hymenoptera: Vespidae), is of Palaearctic origin, being native to Europe, northern Africa and Asia, and introduced into North America, Chile, Argentina, Iceland, Ascension Island, South Africa, Australia and New Zealand. Due to its polyphagous nature and scavenging behaviour, V. germanica threatens agriculture and silviculture, and negatively affects biodiversity, while its aggressive nature and venomous sting pose a health risk to humans. In areas with warmer winters and longer summers, queens and workers can survive the winter months, leading to the build-up of large nests during the following season; thereby increasing the risk posed by this species. To prevent or prepare for such unwanted impacts it is important to know where the wasp may be able to establish, either through natural spread or through introduction as a result of human transport. Distribution data from Argentina and Australia, and seasonal phenology data from Argentina were used to determine the potential distribution of V. germanica using CLIMEX modelling. In contrast to previous models, the influence of irrigation on its distribution was also investigated. Under a natural rainfall scenario, the model showed similarities to previous models. When irrigation is applied, dry stress is alleviated, leading to larger areas modelled climatically suitable compared with previous models, which provided a better fit with the actual distribution of the species. The main areas at risk of invasion by V. germanica include western USA, Mexico, small areas in Central America and in the north-western region of South America, eastern Brazil, western Russia, north-western China, Japan, the Mediterranean coastal regions of North Africa, and parts of southern and eastern Africa.

Black Sigatoka in bananas: Ecoclimatic suitability and disease pressure assessments

“…As in previous work where irrigation is explicitly considered as having a mitigating influence on the distribution of a species [29–32], we provide maps of the projected distribution of P . fijiensis under a natural rainfall scenario and as a composite of both the natural rainfall scenario and the 5 mm day -1 rainfall scenario.…”

Current distribution and voltinism of the brown marmorated stink bug, Halyomorpha halys, in Switzerland and its response to climate change using a high-resolution CLIMEX model

“…Increasing temperatures may also lead to an increase in crop water demand resulting in an expanding area requiring irrigation during summer months, especially in southern and central Europe (EEA 2017;Wada et al 2013). For the invasive wasp, Vespula germanica (Hymenoptera: Vespidae), it was shown that including an irrigation scenario into CLIMEX significantly improved the model fit between present and estimated distribution (de Villiers et al 2017). Similarly, the use of irrigation systems may reduce the potential dry stress of H. halys during summer months, particularly in southern Switzerland, where irrigation is common practise.…”

Environmental niche unfilling but limited options for range expansion by active dispersion in an alien cavity-nesting wasp

“…Contrary to our results on the solitary I. mexicana , in social Hymenoptera niche shift after invasion seems more common. Indeed, a variety of niche shift patterns were observed in the invasive bumblebee Bombus terrestris (L.), in the invasive wasps Vespa velutina Lepeletier and Vespula germanica (Fabricius) and in most of the invasive ants studied so far [ 36 , 37 , 39 , 62 , 63 ]. Interestingly, the only other investigated alien solitary aculeate, the bee Anthidium manicatum (L.), also showed some degree of niche shift, particularly in the southern part of its invaded range (South America) [ 38 ].…”