Breeding the predatory bug Podisus maculiventris Say to protect potatoes from Leptinotarsa decemlineata Say

The predator Podisus maculiventris Say is a representative of the order Hemiptera, family Pentatomidae. This insect is promising in the battle against the Colorado potato beetle Leptinotarsa decemlineata Say. For the successful use of P. maculiventris in the climatic conditions of the Russian Federation and other countries where this predator isn’t found, it is necessary to develop methods of its artificial reproduction. The paper provides information on the selection of food based on the use of phytophagous insects and pests. Among the subjects Galleria mellonella L. caterpillars, Tenebrio molitor L. larvae and pupae, Ephestia kuehniella Zll. caterpillars, as well as Zophobas morio Fabr larvae were used. As a result of the experiment, T. molitor was recognized as the most effective insect prey in terms of biological and economic indicators. When using Tenebrio molitor, the imago yield of P. maculiventris amounted to 81.0-90.5%, which was the best indicator in comparison with other options.

THE POTENTIAL OF THREE LARVAL PREDATORS AGAINST FALL ARMYWORM SPODOPTERA FRUGIPERDA (LEPIDPTERA: NOCTUIDAE) UNDER THE LABORATORY CONDITION

Most cereal crops are often damaged by lepidopterous insects. Of recent, fall armyworm, S. frugiperda (J.E. Smith) has resulted into yield and economic loss in many African and Asian countries. This reduces farmers’ income drastically and to overcome this damage, pesticides have been used which are not also environmentally friendly. Experiments were set up to collect data on the potential of three larval predators Orius strigicollis, Micromus angulatus, and Podisus maculiventris against S. frugiperda. The consumption of S. frugiperda larvae by three predators had highly significant effects (P≤0.05) on first, fourth, and sixth instars. No significant difference was reported between M. angulatus and O. strigicollis on second, third and fifth larval instars of S. frugiperda. O. strigicollis consumed more first larval instar (6.2±0.71) of S. frugiperda than M. angulatus (4.9±1.07) and P. maculiventris (4.2±0.74). However, P. maculiventris consumed more second to sixth larval instars of S. frugiperda than other two predators (O. strigicollis and M. angulatus). The predator P. maculiventris is recommended for controlling S. frugiperda in their second to sixth larval instars while O. strigicollis in the first larval instar. It can be also concluded that fourth larval instars of S. frugiperda is more suitable for its control using predator P. maculiventris as compared to other larval instars. This study therefore recommends predator Podisus maculiventris to be used in control of S. frugiperda under laboratory conditions.

Impact of Imidacloprid Soil Drenching on Survival, Longevity, and Reproduction of the Zoophytophagous Predator Podisus maculiventris (Hemiptera: Pentatomidae: Asopinae)

Systemic insecticides when applied as seed treatments or soil drenches are often more toxicologically selective for natural enemies than target pests. This may not be the case, however, for omnivorous predators, which are at risk of extended exposure to systemically applied pesticides through ingestion while feeding on treated plants for nutrients or water. Such exposure may kill or have sublethal consequences for these natural enemies, compromising their role as biocontrol agents of agricultural pest species. The spined soldier bug, Podisus maculiventris (Say) (Hemiptera: Pentatomidae: Asopinae), is an important zoophytophagous biocontrol agent (i.e., able to substitute zoophagy by phytophagy for survival) that may be exposed to systemic insecticides in many agricultural systems. We, therefore, examined effects on P. maculiventris following exposure to cabbage plants subject to soil-drench treatments with imidacloprid, a systemic neonicotinoid insecticide. Predator survival, development, body weight, and reproduction were recorded. Imidacloprid significantly affected nymph survival and adult emergence, but not duration of the nymphal period or adult body weight. At one-twentieth the recommended field rate for whitefly and aphid management, imidacloprid treatments reduced longevity, fecundity, and fertility of female predators. These findings demonstrate that soil treatments with systemic insecticide can negatively impact zoophytophagous natural enemies.

Discovery of Trissolcus japonicus (Hymenoptera: Scelionidae) in Ontario, Canada

We report the detection and adventive establishment of the samurai wasp, Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), a candidate classical biological control agent for the invasive Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), in southwestern Ontario, Canada. Nine naturally laid, field-collected pentatomid egg masses were collected in 2017 and 2018, and two of these egg masses, belonging to Halyomorpha halys and Podisus maculiventris (Say) (Hemiptera: Pentatomidae), produced adults of T. japonicus. The identification of T. japonicus was confirmed using DNA barcoding as well as morphological characteristics. The remaining egg masses yielded adults of the native Telenomus podisi Ashmead (Hymenoptera: Platygastridae) and Anastatus reduvii (Ashmead) (Hymenoptera: Eupelmidae).

The evaluation of potato virus Y transfer by some beneficial bugs (Hemiptera: Heteroptera)

Pazyuk IM, Fominykh TS. 2019. The evaluation of potato virus Y transfer by some beneficial bugs (Hemiptera: Heteroptera). Biodiversitas 20: 1222-1227. The predatory bugs Podisus maculiventris, Orius majusculus, Nesidiocoris tenuis, and Macrolophus pygmaeus were commonly used for control of pests in potato meristem culture in greenhouses. In this study, the risk of transmission of potato virus Y (PVY) by entomophagous bugs was estimated in cage experiments. It has been shown that none of the bugs tested was capable of transmitting the PVY. However, N. tenuis and M. pygmaeus have been shown to damage potato seedlings in the absence of animal food (pests or factitious food). The bug N. tenuis caused severer damage to potato plants than did the bug M. pygmaeus. Therefore, we can recommend only P. maculiventris and O. majusculus for pest control in potato meristem culture in greenhouses.