Lupin Root Weevils (Charagmus spp., Curculionidae: Sitonini), a Lupin Pest: A Review of Their Distribution, Biology, and Challenges in Integrated Pest Management

Lupins (Lupinus spp.) are an ancient yet important legume crop. In Europe, the protein-rich seeds serve as livestock feed and have the potential to be a healthy vegetarian component of human diets. In some regions in north-eastern Europe, lupins are heavily damaged by two Curculionidae species, the lupin root weevils (LRWs) Charagmus gressorius (syn. Sitona gressorius) and Ch. griseus (syn. S. griseus). Narrow-leaved lupins (L. angustifolius) and white lupins (L. albus) are most affected. The weevils feed on lupin leaves, whereas their larvae feed on root nodules. Therefore, the larvae cause major root damage by creating lacerations that allow soil-borne plant pathogens to enter the plant tissue. These infestations lead to considerable yield losses and markedly reduced N-fixation of the root nodules. This review summarises the current knowledge on the origin, geographical distribution, and biology of these rarely described weevils. It focuses on management strategies, including preconceived insecticide use and potential ecological management methods, as key components of an integrated pest management programme against LRWs in Europe.

Field Diagnosis of Citrus Root Weevil Damage

Root weevils infest citrus groves throughout the citrus growing regions of Florida. Among the eight weevil species that have been identified in Florida citrus groves, five have some potential to cause economic problems for nurserymen and commercial growers. The most important weevil species are Diaprepes root weevil (Diaprepes abbreviatus), southern blue-green citrus root weevil (Pachnaeus litus), and the blue-green citrus root weevil (Pachnaeus opalus). The little leaf notcher (Artipus floridanus) and Fuller rose beetle (Asynonychus godmani) are of less concern, but may be locally important (Fig. 1). This paper will deal with Diaprepes and the blue-green root weevils because they are of major economic importance and frequently occur in citrus groves. This document is HS-1014, one of a series of the Horticultural Sciences Department, UF/IFAS Extension. Original publication date May 2005. HS-1014/HS260: Field Diagnosis of Citrus Root Weevil Damage (ufl.edu)

Effects of some abiotic factors on the exit of poppy root weevils (Ethelcus denticulatus Schrank) (Coleoptera: Curculionidae) from overwintering area

With this study, it is aimed to determine the effects of some abiotic factors on the exit of poppy root weevils (Ethelcus denticulatus Schrank) (Coleoptera: Curculionidae) from their overwintering area. Poppy root weevils is the most important harmful pest of poppy fields (Papaver somniferum L.) (Rhoedales; Papaveraceae). According to the findings, the first adults were seen on the soil on March 10, 2014. It has been observed that as the temperature of the air increases, the number of adults on the soil surface also increases. Thus, it was determined that the number of adults in square meters reached the highest level on April 21, 2014. After this date, it was determined that the number of wintering adults decreased gradually. While the first insect on the surface of the field was caught on March 09, 2015 in the second year. It was determined that the number of highest poppy root weevils caught on the soil surface and in the traps was on April 13, 2015. After this date, it was determined that both the trapped insects and their numbers in m2 decreased. There were significant (P£0.05) correlations between the poppy root weevil exit from their overwintering area and soil temperature (r=0.648, r2=0.461, n=84 P=0.000) and temperature (r=0.59, r2=0.277, n=84, P=0.004) whereas there was no significant correlation between it and soil moisture (r=0.310, r2=0.021, n=84, P=0.466), humidity (r=0.32, r2=0.108, n=84, P=0.87) and rain (r=0.38, r2=0.101, n=84, P=0.73).

Determination Of Some Biological Characteristics Of Poppy Root Weevils (Ethelcus denticulatus (Schrank) (Coleoptera: Curculionidae) For Struggle

With this project, it is aimed to determine the time of the struggle with the poppy root weevils (Ethelcus denticulatus Schrank) (Coleoptera: Curculionidae), which is the most important pest of poppy fields (Papaver somniferum L.) (Rhoedales; Papaveraceae). According to the findings, it has been determined that after the second week of March in the Uşak province, poppy root weevils start to emerge from the soil and adults may be found until the first week of July. The most important factor in the emergence of the pests from soil to surface is temperature. In the second week of March in which effective temperature reached to 14 ºC, the poppy root weevils started to emerge to the soil surface in 2014 and 2015. Peak of the poppy root weevils was determined to be in the second week of April. The sum of effective temperatures at this date was determined to be 70.6 ºC in 2014 and 90.4 ºC in 2015. After the poppy root weevil’s emergence reached the peak, the first larvae began to appear about 10 days later. According to this, when the insect populations are the highest and the sum of effective temperatures is 70 - 90 ºC, it is suggested to make chemical struggle.

Poppy root weevils (Stenocarus ruficornis, Stephens 1831) control in opium poppy (Papaver somniferum L.)

Effects of insecticidal sprays on poppy root weevils (Stenocarus ruficornis, Stephens 1831) were assessed in small plot trials at three localities in the Czech Republic during two years (2011–2012). In addition, the effects of seed dressing were included into the assessment in one of the localities (Červený Újezd). The levels of root damage caused by the insect pest larvae (expressed as number of bore holes per root) and yield got from individual treatments were compared. Sprays applied for 18 days after the first record of poppy root weevils in trials showed the highest effects on a decrease of the levels of root damage (40% of untreated control). In general, sprays applied at the date when SATF₁₄ value exceeded 20°C showed significant effects on decreasing the levels of root damage. The highest effects were usually recorded in sprays which were applied when SATF₁₄ value exceeded 100°C.

Evaluating the Efficacy of the Systems Approach at Mitigating Five Common Pests in Oregon Nurseries

In Oregon, the U.S. Nursery Certification (USNCP), Grower Assisted Inspection (GAIP), and Shipping Point Inspection (SPI) programs are used to certify nursery plants as pest free. To compare the programs' effectiveness for mitigating pest risk, potted plants grown within two USNCP, two GAIP, and two SPI nurseries were surveyed for Phytophthora root rot (Phytophthora spp.), Phytophthora foliar blight (Phytophthora spp.), bittercress (Cardamine spp.), snails and slugs (Class Gastropoda), and root weevils (Otiorhynchus spp.). A total of 1,635 plots were surveyed in the nurseries, with one or more pests detected in 1,003 plots. Based on the total percentage of plots found infested with a pest, significantly fewer were detected in the GAIP nurseries (55%) than in the USNCP nurseries (68%). However, bittercress incidence was significantly higher in GAIP nurseries (21%), while snails and slugs incidence was significantly higher in USNCP nurseries (49%), and Phytophthora root rot incidence was significantly higher in SPI nurseries (31%). Also, the plant families grown by the nurseries had a significant impact on pest incidence for two of the target pests, Phytophthora root rot and root weevils. While the GAIP seemed the best at mitigating pest incidence overall, none of the certification programs was consistently the most effective against all five target pests.