Worldwide decline of the entomofauna: A review of its drivers

Link post

Ab­stract: “Here, we pre­sent a com­pre­hen­sive re­view of 73 his­tor­i­cal re­ports of in­sect de­clines from across the globe, and sys­tem­at­i­cally as­sess the un­der­ly­ing drivers...”
...From our com­pila­tion of pub­lished sci­en­tific re­ports, we es­ti­mate the cur­rent pro­por­tion of in­sect species in de­cline (41%) to be twice as high as that of ver­te­brates, and the pace of lo­cal species ex­tinc­tion (10%) eight times higher, con­firm­ing pre­vi­ous find­ings (Dirzo et al., 2014). At pre­sent, about a third of all in­sect species are threat­ened with ex­tinc­tion in the coun­tries stud­ied (Table 1). More­over, ev­ery year about 1% of all in­sect species are added to the list, with such bio­di­ver­sity de­clines re­sult­ing in an an­nual 2.5% loss of bio­mass wor­ld­wide (Fig. 2)...”

For those con­cerned about wild an­i­mals, such a quick rate of de­cline could give some re­as­surance (in ad­di­tion to the the­o­ret­i­cal ar­gu­ments) that wild in­sect pop­u­la­tions will be small in the long-run. We could have more con­fi­dence in the ex­tent of de­cline if we had a bet­ter han­dle on any pub­li­ca­tion bias in pub­lished pa­pers on con­ser­va­tion and in­sect pop­u­la­tions.

Edit: Note the fol­low­ing com­ment from be­low from Gavin Tay­lor, de­scribing the bi­ased method­ol­ogy used:

> Good point. I was com­ment­ing more on my per­cep­tion of the con­ser­va­tion field rather than con­sid­er­ing bi­ases in the method­ol­ogy of this study, but they key­words used were:
[in­sect*] AND [de­clin*] AND [sur­vey]

Which [is] com­pletely bi­ased to find­ing stud­ies show­ing in­sect de­clines.