Quantifying the unquantifiable: why Hymenoptera, not Coleoptera, is the most speciose animal order

BMC Ecology

Table 2 Calculations of hymenopteran species richness, given numbers of described insect species in other orders and P:H ratios estimated in this paper

	High P:H estimates from case studies	Low P:H estimates from case studies	Half of lowest estimates from case studies
Diptera (152,244)	228,366	199,440	99,720
Lepidoptera (156,793)	286,931	156,793	78,397
Coleoptera (359,891)	494,850	406,677	203,338
Non-parasitoid Hymenoptera (~ 62,000)	79,980	58,900	29,450
All other insect orders (335,970)	0^a	0^a	0^a
Total parasitoid Hymenoptera	1,107,487	833,590	416,795
Non-parasitoid Hymenoptera (to add to calculated parasitoid numbers)	62,000	62,000	62,000
Total Hymenoptera	1,152,127	883,810	472,905

Combining conservative P:H ratio estimates from four case studies with numbers of described species in the four largest insect orders [33, 75] offers an idea of how species richness of the Hymenoptera may compare with that of other orders
^aParastioids attack hosts in all other insect orders, but these are omitted as we did not estimate P:H ratios for any hosts in these orders. Total numbers therefore exclude large numbers of hymenopteran species

ISSN: 1472-6785