Climate change and forest plagues: assessing current and future impacts of diprionid sawflies on the pine forests of north-western Mexico

Abstract

The imminent threat of climate change lies in its potential to disrupt the balance of ecosystems, particularly vulnerable areas such as mountain-top remnant forests. An example of such a fragile ecosystem is the Sierra San Pedro Mártir (SSPM) National Park of Mexico’s Baja California state, where high levels of endemism can be found, and which is home to one of the country’s few populations of the emblematic Jeffrey pine (Pinus jeffreyi). Recent outbreaks of pine-feeding sawfly larvae in SSPM increase the vulnerability of this forest ecosystem, calling for immediate assessments of the severity of this threat. Here, we present a thorough study of the sawfly’s biology and distribution, carrying out molecular and morphology-based identification of the species and creating model-based predictions of the species distribution in the area. The sawfly was found to belong to an undescribed species of the genus Zadiprion (family Diprionidae) with a one-year life-cycle. The distribution of this species appears to be restricted to the SSPM national park and it will probably persist for at least another 50 years, even considering the effects of climate change.

Climatic Suitability and Distribution Overlap of Sawflies (Hymenoptera: Diprionidae) and Threatened Populations of Pinaceae

“…In contrast, for Z. rohweri, the most important bioclimatic variables are related to temperature (mean temperature of the wettest quarter and temperature seasonality), which together make up 88.1% of the calculated niche model (Table 3). As in the case of the studied species of Neodiprion, it seems to be true that each species of Zadiprion has a particular set of bioclimatic variables to define the ecological niche [i.e., annual mean temperature was the best predictor for Z. jeffreyi Smith [10]). It is necessary to carry out a greater number of studies to understand the influence of these variables on the biological cycle of sawflies.…”

“…In forestry, gregarious or solitary larval pine sawflies (Hymenoptera: Diprionidae) can cause problems of economic importance [8] and could be associated with outbreaks in their natural distribution sites, as well as recognized as invasive species [9][10][11].…”

Nueva especie de mosca sierra del género Zadiprion Rohwer (Hymenoptera: Diprionidae) atacando Pinus cembroides (Zucc.) en Tamaulipas, México

“…In 2019, Zadiprion jeffreyi (Smith) was described as a new species attacking Pinus jeffreyi Balf. in Parque Nacional San Pedro Mártir in Baja California, Mexico (Aguilera-Molina, Munguía-Ortega, López-Reyes, Martínez-Aquino, & Ceccarelli, 2019;Smith, 2019). The latter is closely related to Zadiprion rohweri (Middleton) considered a pest of pinyon pines characterized by an inverted "U" on the first lancet ring of the female ovipositor near the dorsum.…”

“…The latter is closely related to Zadiprion rohweri (Middleton) considered a pest of pinyon pines characterized by an inverted "U" on the first lancet ring of the female ovipositor near the dorsum. However, larvae differ in mating and host (Aguilera-Molina et al, 2019;Smith, 2019).…”

First Record in Mexico of Ceromasia auricaudata Townsend (Diptera: Tachinidae) Parasitizing Neodiprion omosus Smith (Hymenoptera: Diprionidae)

“…Many reports have indicated the presence of sawflies of the genus Neodiprion Rohwer, Zadiprion Rohwer, and Monoctenus Dahlbom (Hymenoptera: Diprionidae) in Mexican conifer forests (Smith 1988;Smith et al 2010Smith et al , 2012. Defoliation attributed to sawflies leads to reduced growth in terms of diam, height, and root size in affected trees; if attack is severe and prolonged, it can result in tree death, especially among young trees in the sprouting phase (González-Gaona & Sánchez-Martínez 2018;Aguilera-Molina et al 2019).…”