Ants

Ants (Formicidae)

Ants belong to the Phylum Arthropoda, the Class Hexapoda, and the diverse order Hymenoptera, which also includes bees and wasps including the wood-wasps, sawflies, ichneumon flies, chalcid wasps, hornets, bumble bees, and honey bees. It is one of the largest and most widely distributed orders of insects on the planet, occurring virtually everywhere except Antarctica and the northern hemisphere polar icecap.

About 12,000 ant species have been described to science [some contemporary estimates are higher]; they are estimated to number ten thousand trillion individuals worldwide; and they are thought to have evolved at least 140 million years ago. Today they are the “chief predators of insects and other invertebrates and the principal scavengers of small dead bodies…[They] compose only about 1.4 percent of the world’s insect species [but] their share of the collective body weight is easily ten times greater” (Wilson 2006).

About 100 ant species are known in New England. Of these, 76 species are known from Martha’s Vineyard. The original print version of Island Life cited ongoing work by Stefan Cover, Assistant Curator of the ant collection of the Museum of Comparative Zoology at Harvard (recently retired) and Dr. Paul Z. Goldstein, then of the Florida Museum of Natural History, Gainesville, and included just a partial ant checklist pending the completion and publication of that study. Shortly after the publication Island Life, Ellison et al. 2012 appeared, incorporating the work by Cover and Goldstein; the current checklist is based on distribution information in that excellent field guide. The following summary of Vineyard ants was provided by Dr. Goldstein for the original volume and is only lightly edited here; we gratefully incorporate some corrections and suggestions from Dr. James C. Trager.

There are three groups of ant species known from Massachusetts: (1) boreal species that are relicts of the last glaciation with primarily northern distributions; (2) species typical of the predominant deciduous hardwood forest found generally in the region on the nearby continent; and (3) Coastal Plain species found from the New Jersey Coastal Plain north, some of which reach their northernmost distribution in southeastern Massachusetts. Of the 12 species limited to pine barrens on the northeastern Atlantic coast, three occur on Martha’s Vineyard and at Myles Standish State Forest in Plymouth. All three are found in the New Jersey pine barrens and 10 pine barren species are found on Long Island. One species not native to the island, Tetramorium immigrans, has been introduced. Two species have been collected on Nomans Land Island National Wildlife Refuge which as yet remain unidentified.

Most of the remaining species known from Martha’s Vineyard are associated with deciduous forests, wetlands, and other habitats, most especially open sandy barrens. In fact, more than 50% of the ant species recorded from Martha’s Vineyard require open, sandy barrens habitats rather than deciduous forest. Their occurrence suggests that barrens and shrublands have remained intact on Martha’s Vineyard despite post-colonial deforestation. Indeed, the sandplains supported grassy shrublands prior to colonization by man, and many species that require these open habitats (not grasslands, but grassy shrublands primarily), could not have arrived or persisted here otherwise. The variety of species in open sandy habitats is illustrated by the fact that in one day, 35 species of ants—more than a third of the New England fauna—were recorded in a single firelane at the Manuel Correllus State Forest by T. Simmons and P. Z. Goldstein.

It is clear that the invasion northward by the coastal plain species had already begun and was probably completed by the time the island was cut off from the mainland by the rising sea level about 5,000 years ago. Also, there is one species present here with a very puzzling distribution. Formica knighti occurs here, known from one site in New York but otherwise apparently known only from the Middle West, where it sometimes occupies dry or mesic prairie habitat approximating the well-drained grasslands of Martha’s Vineyard. Whether this species is a relict left from a time when a “peninsula” of prairie reached into what is now the states of New York and Pennsylvania and even into southern New England in the post-glacial period remains to be determined, probably by DNA techniques.

Allan Keith and Paul Goldstein; edited by Matt Pelikan, March 23, 2023.