''Pissodes nemorensis'', known generally as the eastern pine weevil or deodar weevil, is a species of true weevil in the

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

family

Curculionidae The Curculionidae are a family of weevils, commonly called snout beetles or true weevils. They are one of the largest animal families with 6,800 genera and 83,000 species described worldwide. They are the sister group to the family Brentidae. Th ...

. It is found in North America and Africa. Deodar weevils are considered a forest pest in the United States, with adults and larvae feeding on a variety of

coniferous Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

tree species, including trees such as deodar cedar (''

Cedrus deodara ''Cedrus deodara'', the deodar cedar, Himalayan cedar, or deodar, is a species of cedar native to the Himalayas. Description It is a large evergreen coniferous tree reaching tall, exceptionally with a trunk up to in diameter. It has a conic ...

''), loblolly pine (''

Pinus taeda ''Pinus taeda'', commonly known as loblolly pine, is one of several pines native to the Southeastern United States, from East Texas to Florida, and north to southern New Jersey. The wood industry classifies the species as a southern yellow pine. ...

''), longleaf pine (''

Pinus palustris The longleaf pine (''Pinus palustris'') is a pine species native to the Southeastern United States, found along the coastal plain from East Texas to southern Virginia, extending into northern and central Florida. In this area it is also known as ...

''), sand pine (''

Pinus clausa ''Pinus clausa'' is a species of pine endemism, endemic to the Southeastern United States. Its common names include sand pine, Florida spruce pine, and scrub pine. Distribution The tree is found in two separate locations, one across central pen ...

''), shortleaf pine (''

Pinus echinata The shortleaf pine or ''Pinus echinata'' is a species of coniferous tree endemic to the United States. The shortleaf pine is sometimes referred to as the "old field", "spruce", "rosemary", "yellow", "two-leaf" and "heart" pine. The common name " ...

''), slash pine (''

Pinus elliottii ''Pinus elliottii'', commonly known as slash pine,Family, P. P. (1990). Pinus elliottii Engelm. slash pine. ''Silvics of North America: Conifers'', (654), 338. is a conifer tree native to the Southeastern United States. Slash pine is named after ...

''), and spruce pine (''

Pinus glabra A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as c ...

'') Trees of all ages are susceptible to weevil infestations, while trees that are severely stressed by fire, drought, extreme cold, fusiform rust, wind damage, and other problems are prone to weevil infestation. In well-managed pine stands, deodar weevil infestations are sporadic, attacking only the suppressed and unhealthy trees throughout the area. Because they do not typically effect healthy trees, they do not usually alter traditional management strategies. Unlike many other forest pests in the eastern United States, deodar weevils are most active in the winter months, and this is often when sign of infestations can be seen. The best way to avoid a deodar weevil infestation is to maintain good tree and stand health: healthy trees do not typically face mortality or extensive damage from these pests. If an infestation has occurred, pesticides can be used in the fall as the weevils become active, but are typically not recommended.

Description

Sources:

Adult

Deodar weevils adults are approximately 7mm long; can range from a rusty red to grayish brown in color on the head and the body. Like most other weevil species have a long snout (or

proboscis A proboscis () is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular arthropod mouthparts, mouthparts used for feeding and sucking. In vertebrates, a pr ...

) and a small head. They also have the weevil clubbed antennae that are 'elbowed' located near the tip of the snout. On the top of the

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main di ...

, there are two distinct white spots. An additional spot occurs on the thorax at the base of the wings (the scutellum). The abdomen can have various splotchy patterns along the wing casings (

elytra An elytron (; ; : elytra, ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometime ...

) with two larger white spots or splotches on the rear or posterior portion.

Pupa

Similar in size and shape as the adult weevils, but are instead a creamy white color. The legs are crumpled beneath the already well formed proboscis. Their wing pads are wrapped around the thorax, and the head has low spines. As they approach time to molt, their shell darkens to shades more similar to the adult form.

Larvae

Newly hatched larvae are small (<2mm) growing to 12mm when mature. Much like other beetle larvae, deodar weevil larvae have a plump white ridged and legless abdomen, and an amber to brown helmet head.

Biology and reproduction

Adult weevils become active in fall, feed and mate, and females lay eggs in the holes made while feeding in the bark. Newly hatched grubs bore under the bark where they feed, molt, and grow. The pupae occupy chambers (chip cocoons) made by the larvae. Adult weevils begin emerging in March but most of the new adult weevils emerge in May (small circular escape holes are sometimes noticed on infested stems). The new weevils apparently

aestivate Aestivation ( (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a lowered me ...

during the summer and become active as the weather cools down in the fall when they infest stressed trees, feed and mate. Deodar weevils usually don't infest trees younger than age 5 (they need stems large enough to support larval galleries). Deodar weevils tend to infest the bottom 10 feet of the main stem. These weevil grubs feed beneath the bark and sometimes girdle the stem causing it to die from the damaged portion outward. The bark may swell over the feeding areas. Deodar weevils have killed trees up to 36 feet tall as the weevils attack the lower trunk. Infested shoots may die, causing excessive branching. In addition, deodar weevils can vector pitch canker (''

Fusarium moniliforme ''Fusarium verticillioides'' is the most commonly reported fungal species infecting maize (''Zea mays''). ''Fusarium verticillioides'' is the accepted name of the species, which was also known as ''Fusarium moniliforme''. The species has also bee ...

'') The weevils are active all winter long and lay one to four or five eggs in the inner bark in holes chewed through the bark, but fall is the peak time for adult feeding and breeding. The weevils do some minor damage as they feed on the bark before laying their eggs. There is one generation per year.

References

External links

{{Taxonbar, from=Q24956199 Molytinae Articles created by Qbugbot Beetles described in 1824 Taxa named by Ernst Friedrich Germar Insect pests of temperate forests