Curculio caryae
Encyclopedia
The pecan weevil, Curculio caryae (Coleoptera: Curculionidae
) is an obligate feeder on the nuts of North American
hickories
and pecan
s (Carya species), most widely recognized as an economically important pest of the pecan, Carya illinoinensis (Fagales
: Juglandaceae
). It has also been observed to infest one Juglans species, the Persian walnut
, Juglans regia.
Adult pecan weevils are approximately 3/8 in long, medium-brown beetle
s with a proboscis
of equal length to their body, which has mouthparts at the distal end. The females use their proboscis to chew a hole through the husk
of developing nuts and deposit eggs inside, which hatch into legless, creamy-white larvae
with reddish-brown head capsules that feed inside the nuts from late summer
through fall, developing through several instar
s up to 3/5 in long at full growth. In late fall and early winter, mature larvae chew a small hole in the nut shell and drop to the ground, where they burrow into the soil and construct a cell
in which they remain for eight to ten months before pupating and transforming into adults. Newly formed adults remain in their cells in the soil and emerge the following year, two years after the beginning of the cycle, although some larvae do not pupate and transform to adults until an additional year has passed and the life cycle for some of each generation may take up to three years.
Their economic importance results from crop loss due to their feeding and egg laying on the developing pecan nuts causing them to drop from the tree, and the destruction of the edible nut kernel
by the larvae feeding inside the shell.
Curculionidae
Curculionidae is the family of the "true" weevils . It was formerly recognized in 1998 as the largest of any animal family, with over 40,000 species described worldwide at that time...
) is an obligate feeder on the nuts of North American
North American
North American generally refers to an entity, people, group, or attribute of North America, especially of the United States and Canada together.-Culture:*North American English, a collective term used to describe American English and Canadian English...
hickories
Hickory
Trees in the genus Carya are commonly known as hickory, derived from the Powhatan language of Virginia. The genus includes 17–19 species of deciduous trees with pinnately compound leaves and big nuts...
and pecan
Pecan
The pecan , Carya illinoinensis, is a species of hickory, native to south-central North America, in Mexico from Coahuila south to Jalisco and Veracruz, in the United States from southern Iowa, Illinois, Missouri, and Indiana east to western Kentucky, southwestern Ohio, North Carolina, South...
s (Carya species), most widely recognized as an economically important pest of the pecan, Carya illinoinensis (Fagales
Fagales
The Fagales are an order of flowering plants, including some of the best known trees. The order name is derived from genus Fagus, Beeches. They belong among the rosid group of dicotyledons...
: Juglandaceae
Juglandaceae
The Juglandaceae, also known as the Walnut Family, is a family of trees, or sometimes shrubs, in the order Fagales. Various members of this family are native to the Americas, Eurasia, and Southeast Asia....
). It has also been observed to infest one Juglans species, the Persian walnut
Persian Walnut
Juglans regia, the Persian walnut, English walnut, or especially in Great Britain, Common walnut, is an Old World walnut tree species native to the region stretching from the Balkans eastward to the Himalayas and southwest China...
, Juglans regia.
Adult pecan weevils are approximately 3/8 in long, medium-brown beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s with a proboscis
Proboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In simpler terms, a proboscis is the straw-like mouth found in several varieties of species.-Etymology:...
of equal length to their body, which has mouthparts at the distal end. The females use their proboscis to chew a hole through the husk
Husk
Husk in botany is the outer shell or coating of a seed. It often refers to the leafy outer covering of an ear of maize as it grows on the plant. Literally, a husk or hull includes the protective outer covering of a seed, fruit or vegetable...
of developing nuts and deposit eggs inside, which hatch into legless, creamy-white larvae
Larvae
In Roman mythology, lemures were shades or spirits of the restless or malignant dead, and are probably cognate with an extended sense of larvae as disturbing or frightening...
with reddish-brown head capsules that feed inside the nuts from late summer
Summer
Summer is the warmest of the four temperate seasons, between spring and autumn. At the summer solstice, the days are longest and the nights are shortest, with day-length decreasing as the season progresses after the solstice...
through fall, developing through several instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
s up to 3/5 in long at full growth. In late fall and early winter, mature larvae chew a small hole in the nut shell and drop to the ground, where they burrow into the soil and construct a cell
Cell
-Science and technology:*Cell , the functional basic unit of life*Cell , a term used in an electronic circuit design schematics*Cell , a three-dimensional element, part of a higher-dimensional object*Cell , a scientific journal...
in which they remain for eight to ten months before pupating and transforming into adults. Newly formed adults remain in their cells in the soil and emerge the following year, two years after the beginning of the cycle, although some larvae do not pupate and transform to adults until an additional year has passed and the life cycle for some of each generation may take up to three years.
Their economic importance results from crop loss due to their feeding and egg laying on the developing pecan nuts causing them to drop from the tree, and the destruction of the edible nut kernel
Kernel
-Computer science:* Kernel , the central component of most operating systems** The Linux kernel, from GNU/Linux operating systems** The Windows 9x kernel, used in Windows 95, 98 and ME...
by the larvae feeding inside the shell.