Search Results (6)

Insect predators can suppress prey populations through increased progeny production. The present study investigated the numerical responses of adult♀ Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) on a diet of Liposcelis decolor (Pearman) (Psocodea: Liposcelididae). Adult♀ X. flavipes were placed in arenas containing nymphs, adult females, or males of L. decolor at varying prey densities under laboratory conditions at 28 ± 1 °C, 63 ± 5 RH, and a 0:24 (L:D) photoperiod. The number of eggs laid by the predator was assessed at 24 h intervals for five days, and this was used to determine oviposition rate, oviposition efficiency, and efficiency of conversion of ingested food resources (ECI). This study showed that prey stage did not affect oviposition rate; however, there was a positive correlation between prey density and X. flavipes oviposition rate for all the prey stages. The predator’s oviposition efficiency and ECI (%) were inversely proportional to prey density for all prey stages. The current study shows that X. flavipes can produce more offspring on adults and nymphs of L. decolor when prey densities are high and can establish at low prey densities. Further evaluation of X. flavipes under field storage conditions is recommended to facilitate its incorporation into integrated management of psocids. Full article

Psocids are difficult to manage using grain protectants and phosphine hence research on non-chemical control methods. This study evaluated the effectiveness of Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) at managing Liposcelis decolor (Pearman) (Psocodea: Liposcelididae). The functional responses of adult♀ and nymphs of X. flavipes on a diet of nymphs, adult♂, and adult♀ of L. decolor were determined under laboratory conditions at 28 ± 1 °C, 63 ± 5% RH, and a 0:24 (L:D) photoperiod. Maximum likelihood estimates (MLEs) of a logistic regression analysis showed that the functional responses of the life stages of X. flavipes on diets of three stages of L. decolor were Holling Type II. Estimates of the attack rate (a), handling time (Th), maximum predation (K) per day, and predation efficiency (η) per day for the two predator life stages against each prey life stage showed that the adult♀ X. flavipes predation rate was better compared with the nymphs. The adult♀ X. flavipes per capita consumption rate and searching efficiency were also higher than those of the nymphs. The data showed adults of L. decolor are more favorable for adult♀ X. flavipes whereas their nymphs prefer nymphs of L. decolor. Field evaluation of X. flavipes is required for their incorporation into psocid pest management. Full article

Predator–prey interactions are linked through trophic relationships, and individual population dynamics are a function of multiple interactions among many ecological factors. The present study considered the efficacy of the predatory mites Cheyletus eruditus (Schrank) (Trombidiformes: Cheyletidae) and Cheyletus malaccensis Oudemans to manage Liposcelis decolor (Pearman) (Psocodea: Liposcelididae). Prey population suppression and progeny replacement efficiency of the predators were assessed under different predator–prey ratios (0:20, 1:20, 2:20, 4:20, and 10:20), temperatures (20, 24, 28, and 32 °C), and relative humidities (RH) (63, 75, and 85%) over 40 days under laboratory conditions of 0:24 (L:D) photoperiod. Suppression of L. decolor population when C. eruditus-related predator-to-prey ratios of 1:20, 2:20, 4:20, and 10:20 were used was ~61.7, 79.7, 85.1, and 87.5%, respectively, relative to the Control ratio (0:20). In the case of C. malaccensis, suppression of 70, 82.1, 92.9, and 96.5%, respectively, was achieved. Although the low 63% RH limited efficacy of these cheyletid mites, both predatory mites caused pest population suppression of ~67.1–97.2% and increased their progeny by ~96.7–844.4% fold for the predator–prey ratios of 1:20, 2:20, 4:20, and 10:20, temperatures of 20, 24, 28, and 32 °C, and RH levels of 63, 75, and 85%. The levels of psocid population suppression achieved indicate the potential of both predatory mites for psocid management. Full article

Cheyletus malaccensis Oudemans and Cheyletus eruditus (Schrank) are predators of stored-grain pests in China. The psocid Liposcelis bostrychophila Badonnel is prone to outbreaks in depots. To assess the potential of large-scale breeding with Acarus siro Linnaeus and the biological control potential of C. malaccensis and C. eruditus against L. bostrychophila, we determined the development times of different stages at 16, 20, 24, and 28 °C and 75% relative humidity (RH) while feeding on A. siro, as well as the functional responses of both species’ protonymphs and females to L. bostrychophila eggs at 28 °C and 75% RH. Cheyletus malaccensis had a shorter development time and longer adult survival time than C. eruditus at 28 °C and 75% RH and could establish populations faster than C. eruditus while preying on A. siro. The protonymphs of both species showed a type II functional response, while the females showed a type III functional response. Cheyletus malaccensis showed a higher predation ability than C. eruditus, and the females of both species had a higher predation ability than the protonymphs. Based on the observed development times, adult survival times, and predation efficiency, Cheyletus malaccensis has much greater biocontrol potential than C. eruditus. Full article

We established a new genus with a new species Brachyantennum spinosum Liang et Liu, gen. et sp. nov. from mid-Cretaceous Burmese Kachin amber. It is tentatively placed into the suborder Trogiomorpha, based on the strong external valve, the reduced dorsal and ventral valve, and the short subgenital plate covering the basal part of the external valve. This new genus is apparently close to the family Cormopsocidae, based on the well-developed and very long hindwing Sc vein. However, its familial placement is ambiguous and it can be excluded from the established families of Trogiomorpha by the presence of the tarsal ctenidiobothria on the mid- and hindleg. Full article

Psocids are a new risk for global food security and safety because they are significant worldwide pests of stored products. Among these psocids, Liposcelis bostrychophila has developed high levels of resistance or tolerance to heat treatment in grain storage systems, and thus has led to investigation of molecular mechanisms underlying heat tolerance in this pest. In this study, the time-related effects of thermal stress treatments at relatively high temperatures on the activities of antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), peroxidases (POD), glutathione-S-transferases (GST) and malondialdehyde (MDA), of L. bostrychophila were determined. Thermal stress resulted that L. bostrychophila had a significantly higher MDA concentration at 42.5 °C, which indicated that the heat stress increased lipid peroxidation (LPO) contents and oxidative stress in this psocid pest. Heat stress also resulted in significant elevation of SOD, CAT and GST activities but decreased POD activity. Our data indicates that different antioxidant enzymes contribute to defense mechanisms, counteracting oxidative damage in varying levels. POD play minor roles in scavenging deleterious LPO, while enhanced SOD, CAT and GST activities in response to thermal stress likely play a more important role against oxidative damage. Here, we firstly identified five LbHsps (four LbHsp70s and one LbHsp110) from psocids, and most of these LbHsps (except LbHsp70-1) are highly expressed at fourth instar nymph and adults, and LbHsp70-1 likely presents as a cognate form of HSP due to its non-significant changes of expression. Most LbHsp70s (except LbHsp70-4) are significantly induced at moderate high temperatures (<40 °C) and decreased at extreme high temperatures (40–45 °C), but LbHsp110-1 can be significantly induced at all high temperatures. Results of this study suggest that the LbHsp70s and LbHsp110 genes are involved in tolerance to thermal stress in L. bostrychophila, and antioxidant enzymes and heat shock proteins may be coordinately involved in the tolerance to thermal stress in psocids. Full article