''Neodiprion pinetum'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

sawfly Sawflies are the insects of the suborder Symphyta within the order Hymenoptera, alongside ants, bees, and wasps. The common name comes from the saw-like appearance of the ovipositor, which the females use to cut into the plants where they lay ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Diprionidae The Diprionidae are a small family of conifer-feeding sawflies (thus the common name conifer sawflies, though other Symphyta also feed on conifers) restricted to the Northern Hemisphere, with some 140 species in 13 genera. Larvae are often grega ...

. It is commonly known as the white pine sawfly, a name sometimes also applied to '' Diprion similis'', because the larvae of both species feed on the needles of the

white pine ''Pinus'', the pines, is a genus of approximately 111 extant tree and shrub species. The genus is currently split into two subgenera: subgenus ''Pinus'' (hard pines), and subgenus ''Strobus'' (soft pines). Each of the subgenera have been further ...

(''Pinus strobus'').

Description

The adult ''N. pinetum'' is a broad-bodied insect with membranous wings. Females have a saw-like

ovipositor The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

at the tip of the abdomen and are larger than males. The larvae have black heads and are creamy-coloured or yellowish, with four longitudinal rows of black spots.

Distribution

''N. pinetum'' is native to North America, its range extending through the eastern United States to southeastern Canada.

Hosts

The main

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

for the larvae of this species is the white pine (''Pinus strobus''), but it also occurs on the

pitch pine ''Pinus rigida'', the pitch pine, is a small-to-medium-sized pine. It is native to eastern North America, primarily from central Maine south to Georgia and as far west as Kentucky. It is found in environments which other species would find unsuit ...

(''Pinus rigida''), short-leaf pine (''Pinus echinata''), the

red pine ''Pinus resinosa'', known as red pine (also Norway pine in Minnesota), is a pine native to North America. Description Red pine is a coniferous evergreen tree characterized by tall, straight growth. It usually ranges from in height and in trun ...

(''Pinus resinosa'') and the Swiss mountain pine (''Pinus mugo'').

Ecology

The adult sawflies appear in late spring. The female uses its ovipositor to cut a slit along the edge of a pine needle and lays several eggs in this. If mating has occurred, both male and female offspring develop, but unmated females can also lay viable eggs, and these result in entirely male offspring. Each female lays about one hundred eggs over the course of a few months. The first

instar An instar (, from the Latin '' īnstar'', "form", "likeness") is a developmental stage of arthropods, such as insects, between each moult (''ecdysis''), until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or ass ...

larvae are gregarious and consume the surface layer of the needles but later instars spread out through the foliage and consume the whole needle. They feed on both old and young pine needles; heavy infestations can seriously defoliate the tree and isolated clumps of white pine can be killed. When the larvae are fully developed, they descend to the ground where they make cocoons among the leaf litter; in these they overwinter as non-feeding prepupae,

pupa A pupa ( la, pupa, "doll"; plural: ''pupae'') is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their ...

ting in the spring and emerging as adults a few weeks later. Several parasitic wasps attack the larvae of this sawfly, and the egg parasitoid '' Closterocerus cinctipennis'' was found to be 90% effective in controlling an outbreak of the pest in

Crawford County, Wisconsin Crawford County is a county in the southwest part of the U.S. state of Wisconsin. As of the 2020 census, the population was 16,113. Its county seat is Prairie du Chien. History Along with Brown County, Crawford County is one of Wisconsin's or ...

References

{{Taxonbar, from=Q14452960 Tenthredinoidea Pest insects Insects described in 1869