0000002511 00000 n Figure 7. The pecan weevil, Curculio caryae (Coleoptera: Curculionidae) is an obligate feeder on the nuts of North American hickories and pecans (Carya species), most widely recognized as an economically important pest of the pecan, Carya illinoinensis (Fagales: Juglandaceae). Beneficial nematodes for control of pecan weevils. After shell hardening, treat when weevils begin to emerge and continue spraying at 7-10 days interval especially following rainy days. 11). Adult weevils and larvae overwinter in the soil. The larvae are cream colored grubs with reddish heads. ... Larvae on pecan feed in phylloxera galls in spring. Choose blocks that have known history of pecan weevil infestations for monitoring. Larvae and pupae become common in flower beds and gardens in which acorns have fallen. They are found in the nuts during late summer and early fall and can be found in the soil beneath infested trees during the rest of the year. Pecan and hickory Damage. 0000003169 00000 n Adults can be sampled with emergence traps in the soil or with a beating sheet. Pecan and hickory Damage. Pecan trees are common in eastern North Carolina. For more information on pecan weevil control and other research-based orchard management practices, consult OSU Extension fact sheets, available online and through all county Extension offices . The main type of damage is caused by larvae feeding within the nut. (A) Eggs, circled; (B) 4th instar larva; (C) Pupa inside earthen cell and (D) Adult female on pecan. %PDF-1.3 %���� The egg is attached to the shuck with a creamy white substance visible on the shuck surface. Hickory shuckworm, Cydia caryana (Fitch) (Lepidoptera: Tortricidae), larvae occur in shucks of pecan nuts. In most years, larvae damage results in the most yield loss. The main type of damage is caused by larvae feeding within the nut. Each female weevil can oviposit 30 to 54 eggs; therefore, one weevil could affect as many as 15 to 27 or as few as 7 to 13 pecans, assuming there are two to four larvae per nut, respectively. Pecan [Carya illinoinensis (Wangenh.)K. One prime example is the so-called plum curculio (Conotrachelus nenuphar), which is a serious pest on a wide variety of stone fruits. Where it is found in Texas, the pecan weevil is the most damaging late-season pecan pest. The head is yellow to brown. Life cycle The adult PW typically emerges from the soil as early as July 25, frequently two to three days after a heavy rain. Workers at an Otero County pecan cleaning plant noticed pecans with round holes about the diameter of a BB pellet, which are the pecan weevil's emergence holes. To control the weevil, it is recommended to target with … Between late September and December larvae exit nuts through a small circular hole, drop to the ground and burrow into the soil to a depth of 4-12 inches. Larval emergence holes in pecan nut shucks and shells begin to appear in late September and continue as long as larvae are alive. The only possible time to manage infestations is after adults have emerged from the soil and before egg laying starts. trailer << /Size 52 /Info 26 0 R /Root 29 0 R /Prev 280064 /ID[<8b5080b40d262f6b3a54b5e468d931bc>] >> startxref 0 %%EOF 29 0 obj << /Type /Catalog /Pages 25 0 R /Metadata 27 0 R /PageLabels 24 0 R >> endobj 50 0 obj << /S 62 /L 129 /Filter /FlateDecode /Length 51 0 R >> stream Before shell hardening, treat if high numbers of weevils are seen or if nut drop caused by weevil feeding is high. Attraction of the pecan weevil to the synthetic boll weevil pheromone. Please keep in mind that the original opening on the trap top was designed for the boll weevil, which is a much smaller weevil, so be sure to check that the opening is somewhat enlarged for the larger pecan weevil. Biological Control of the Pecan Weevil: Smith et al. Two to four larvae within each infested nut can easily destroy the entire kernel. One prime example is the so-called plum curculio (Conotrachelus nenuphar), which is a serious pest on a wide variety of stone fruits. Description The adult is a brownish weevil about 3/8 inch long. Pecan Weevil Alert Pecan weevil management decision-making is already upon us. In late fall and early winter, about 42 days after eggs are laid, full-grown larvae chew a 1/8 diameter hole in the shell and drop to the ground. Pecan Weevil. Pecan weevils damage nuts in two ways. Its larvae (soft, white grubs without legs) and white pupae are similar to those of the rice and maize weevil. The larvae emerge from the nuts about 42 days after the eggs are deposited. Grubs overwinter in earthen cells in the ground. They spend one to two years in th… Please keep in mind that the original opening on the trap top was designed for the boll weevil, which is a much smaller weevil, so be sure to check that the opening is somewhat enlarged for the larger pecan weevil. Scientific Name: Curculio caryae (Horn) One of the most devastating insects on pecans is the pecan weevil. The entire life cycle takes 2 or 3 years. early egg-laying period, from early August to mid-September. Damage: The pecan weevil causes two types of direct damage to pecans. 1987; Holloway 1980. Once the larvae hatch, they feed on the kernel for about 35 days. Pecan weevil: suppression of larvae with the fungi Metarrhizium anisopliae and Beauveria bassiana and the nematode Neoaplectana dutkyi. First, they feed on the young nuts in late summer, causing some to drop early still in their husks and never complete development. Pecan weevil: suppression of larvae with the fungi Metarrhizium anisopliae and Beauveria bassiana and the nematode Neoaplectana dutkyi. Common Name: Pecan weevil 0000001123 00000 n 28 0 obj << /Linearized 1 /O 30 /H [ 920 224 ] /L 280752 /E 108681 /N 5 /T 280074 >> endobj xref 28 24 0000000016 00000 n