Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.

Diaphania indica (Saunders) (Lepidoptera: Crambidae) is an important phytophagous pest of Trichosanthes anguina L. in India. We studied life table parameters by age-stage, two-sex, amylolytic and proteolytic activities, and food utilization parameters of D. indica on the leaves of three T. anguina cultivars (Baruipur Long, Polo No. 1 and MNSR-1). Further, nutrients (total carbohydrates, proteins, lipids, amino acids and nitrogen) and antinutrients (total phenols, flavonols and tannins) in leaves were determined. The development time (egg to adult emergence) was the shortest on MNSR-1 (19.79 d) and the longest on Polo No. 1 (25.72 d). Fecundity was the highest and lowest on MNSR-1 (259 eggs) and Polo No. 1 (151.22 eggs), respectively. The lowest intrinsic rate of increase (rm) and net reproductive rate (R0) of D. indica on Polo No. 1 were 0.1112 d−1 and 27.22 offspring individual−1, respectively. The mean generation time (T) was the shortest on MNSR-1 (23.99 days) and the longest on Polo No. 1 (29.70 d). The larvae of D. indica fed with MNSR-1 had the highest level of amylolytic and proteolytic activities, and the lowest activities were in the larvae fed with Polo No. 1. The fifth-instar larvae fed with Polo No. 1 had the lowest consumption index and growth rate. The higher larval development time and lower fecundity of D. indica on Polo No. 1 were due to the lower level of nutrients and a higher level of antinutrients than other cultivars. Our results concluded that Polo No. 1 cultivar could be suggested for cultivation.

Pear psyllids (Hemiptera: Psylloidea: Psyllidae: Cacopsylla spp.) belong to the most serious pests of pear (Pyrus spp.). They damage pear trees by excessive removal of phloem sap, by soiling the fruits with honeydew which, in turn, provides a substrate for sooty mould, and by transmission of Candidatus Phytoplasma spp., the causal agents of the pear decline disease. The morphological similarity, the presence of seasonal dimorphism that affects adult colour, size and wing morphology and uncritical use of species names, led to much confusion in the taxonomy of pear psyllids. As a result, pear psyllids have been frequently misidentified. Many of the entries attributed to Cacopsylla pyricola and other species in the GenBank are misidentifications which led to additional, unnecessary confusion. Here we analysed DNA barcodes of 11 pear psyllid species from eastern Asia, Europe and Iran using four mitochondrial gene fragments (COI 658 bp, COI 403 bp, COI-tRNAleu-COII 580 bp and 16S rDNA 452 bp). The efficiency of identification was notably high and considerable barcoding gaps were observed in all markers. Our results confirm the synonymies of the seasonal forms of Cacopsylla jukyungi ( = C. cinereosignata, winter form) and C. maculatili ( = C. qiuzili, summer form) previously suggested based on morphology. Some previous misidentifications (C. chinensis from China, Japan and Korea = misidentification of C. jukyungi; C. pyricola and C. pyrisuga from East Asia = misidentification of C. jukyungi and C. burckhardti, respectively; C. pyricola from Iran = misidentification of C. bidens, C. pyri and Cacopsylla sp.) are also corrected. There is no evidence for the presence of European pear psyllid species in East Asia.

The onion thrips (Thrips tabaci Lindeman, 1889) is a key pest of a wide range of crops because of its ecological attributes such as polyphagy, high reproduction rate, ability to transmit tospoviruses and resistance to insecticides. Recent studies revealed that T. tabaci is a cryptic species complex and it has three lineages (leek-associated arrhenotokous L1-biotype, leek-associated thelytokous L2-biotype and tobacco-associated arrhenotokous T-biotype), however, the adults remain indistinguishable. T. tabaci individuals were collected from different locations of Hungary to create laboratory colonies from each biotypes. Mitochondrial COI (mtCOI) region was sequenced from morphologically identified individuals. After sequence analysis SNPs were identified and used for CAPS marker development, which were suitable for distinguishing the three T. tabaci lineages. Genetic analysis of the T. tabaci species complex based on mtCOI gene confirmed the three well-known biotypes (L1, L2, T) and a new biotype because the new molecular evidence presented in this study suggests T-biotype of T. tabaci forming two distinct (sub)clades (T1 and T2). This genetic finding indicates that the genetic variability of T. tabaci populations is still not fully mapped. We validated our developed marker on thrips individuals from our thrips colonies. The results demonstrated that the new marker effectively identifies the different T. tabaci biotypes. We believe that our reliable genotyping method will be useful in further studies focusing on T. tabaci biotypes and in pest management by scanning the composition of sympatric T. tabaci populations.

We investigated the effects of the antiparasitic drug ivermectin on the dung beetles Copris acutidens Motschulsky, Onthophagus bivertex Heyden, O. lenzii Harold and Phelotrupes auratus auratus Motschulsky in Japan. Ivermectin was detected in cattle dung from 1 to 3 or 7 days post-treatment, with a peak at 3 days post-treatment in two pour-on administrations (500 µg kg−1). In C. acutidens, adult survivals and numbers of brood balls were significantly reduced in dung collected at 3 and 7 days post-treatment, and adult emergence rates were significantly decreased in dung collected at 7 and 14 days post-treatment. Feeding activity of C. acutidens was inhibited in dung collected at 3 days post-treatment, but was not significantly different from that seen in control dung at 7 and 14 days post-treatment. In O. bivertex and O. lenzii, there were no effects of ivermectin on adult survival or feeding activities, but the numbers of brood balls of O. bivertex constructed in dung collected at 3 and 7 days post-treatment were significantly lower than observed with control dung. The adult emergence rates of O. bivertex and O. lenzii were significantly reduced in dung collected at 1 to 3 and 1 to 7 days post-treatment, respectively. In P. auratus, there were no effects of ivermectin on adult survival, oviposition, feeding activity, or larval survival (until the third instar) in dung at 3 days post-treatment. The environmental risks affecting the populations of dung beetles in Japan are discussed.

The Chinese white pine beetle Dendroctonus armandi (Coleoptera: Scolytinae) typically displays bivoltinism at altitudes below 1700 m in the Qinling Mountains, China. The periods of host colonization and larval overwintering are two important phases in the life cycle of bark beetles, as it is during these periods that they have to contend with host plant defences and periods of intense cold, respectively. Although during different seasons, the females and males of Chinese white pine beetles show varying tolerances to host plant terpenoids, the sex ratio and survival physiology condition of the two beetle generations are unknown. We investigated the sex ratio of individuals, and also examined the body mass, energy stores, and detoxication enzymes of males and females in each of the two generations in order to determine the overall population stability of each generation. We identified a female-biased sex ratio among adults in both generations. Furthermore, patterns of body mass, energy stores, and detoxication enzymes were found to differ between the two sexes and two seasons. Compared with the males, the females have a larger body mass and higher amounts of stored lipids, which are assumed to be adaptations designed to overcome host resistance and facilitate subsequent oviposition.

Better performance of generalist predators, as well as an increase in their density, may be an incentive factor in the ability of the predators to exploit more than one food item or mixed diets. In this study, the effects of four pollen grains (cedar, pear, apricot, and pistachio) when provided to Neoseiulus californicus in mixed diets with prey, Tetranychus urticae, were evaluated. The result indicated that the fastest female developmental time was observed on pistachio pollen + T. urticae, together with apricot pollen + T. urticae. Females reared on the mixed diet comprising pistachio pollen reflected the longest total life span duration, while the shortest total life span was observed in those on the diet that included pear pollen. Furthermore, the lowest fecundity, as well as the shortest reproduction period, was determined on the diets that included pear pollen, while the highest fecundity and the longest reproduction period were observed in pistachio pollen + T. urticae. In addition, the intrinsic (r) and finite rate of increase (λ), net (R0) and gross (GRR) reproductive rates were highest in pistachio pollen + T. urticae. These findings have important implications for developing a comprehensive biological control program of T. urticae, which will be discussed.

This study aimed to evaluate the effects of toxic baits and attractants for fruit flies on the biology of its parasitoid Fopius arisanus. We tested two food-based attractants; hydrolysed corn protein (Biofruit® 3%) and sugarcane molasses (7%), their mixtures with spinosad and malathion-based insecticides, and a ready-to-use commercial bait (Success 0.02 CB®). Malathion-based lures were used as references for mortality (i.e., positive control), while negative control was honey. The formulations Biofruit® + malathion (T1), molasses + malathion (T2), and spinosad + molasses (T3) were toxic to F. arisanus, being classified as harmful (class 4). In addition, toxic baits composed of Biofruit + spinosad (T4) reduced parasitism by 97.99%, being rated as moderately harmful (class 3). Yet, Success 0.02 CB® (T7) was considered slightly toxic (class 2), causing a 64.55% reduction in parasitism. Regarding the biological parameters of F. arisanus, offspring number and parasitoid longevity were significantly reduced by using hydrolysed protein attractants when compared to the control (honey). However, sugarcane molasses improved parasitoid reproduction and longevity, as did the honey. Lastly, ingestion tests showed the major role of attractants in toxic-bait formulations against F. arisanus.

Sitophilus zeamais is a key pest of stored grains. Its control is made, usually, using synthetic insecticides, despite their negative impacts. Botanical insecticides with fumigant/repellent properties may offer an alternative solution. This work describes the effects of Anethum graveolens, Petroselinum crispum, Foeniculum vulgare and Cuminum cyminum essential oils (EOs) and (S)-carvone, cuminaldehyde, estragole and (+)-fenchone towards adults of S. zeamais. Acute toxicity was assessed by fumigation and topical application. Repellence was evaluated by an area preference bioassay and two-choice test, using maize grains. LC50 determined by fumigation ranged from 51.8 to 535.8 mg L−1 air, with (S)-carvone being the most active. LD50 values for topical applications varied from 23 to 128 µg per adult for (S)-carvone > cuminaldehyde > A. graveolens > C. cyminum > P. crispum. All EOs/standard compounds reduced significantly the percentage of insects attracted to maize grains (65–80%) in the two-choice repellence test, whereas in the area preference bioassay RD50 varied from 1.4 to 45.2 µg cm−2, with cuminaldehyde, (S)-carvone and estragole being strongly repellents. Petroselinum crispum EO and cuminaldehyde affected the nutritional parameters relative growth rate, efficiency conversion index of ingested food and antifeeding effect, displaying antinutritional effects toward S. zeamais. In addition, P. crispum and C. cyminum EOs, as well as cuminaldehyde, showed the highest acetylcholinesterase inhibitory activity in vitro (IC50 = 185, 235 and 214.5 µg mL−1, respectively). EOs/standard compounds exhibited acute toxicity, and some treatments showed antinutritional effects towards S. zeamais. Therefore, the tested plant products might be good candidates to be considered to prevent damages caused by this pest.

Decreased reliance on pesticides can be achieved through a clever use of eco-evolutionary knowledge via intercropping economically valuable crops with companion plants that can hamper pest outbreaks. We created a greenhouse multi-layered microcosm system to test two potato peach aphid clones, performing alone or in competition, on mixes of genetically variable cultivars of cabbage, with and without onion. The onion acted as a nuisance/disturbance for the pest, which was generally for the benefit of the cabbage albeit both plants sharing space and nutrients. The onion effect was context-specific and differed by aphid genotype. Onion variable nuisance negatively affected the numbers of one aphid genotype (green) across all contexts, while the other genotype (pink) numbers were decreased in two contexts only. However, the green performed better than the pink on all cases of cabbage di-mixes despite its numbers being capped when the onion was present. Further, there was also a general aphid propensity to wander off the plant along with a differential production of winged morphs to escape the onion-affected environments. Moreover, through a comparative increase in dry mass, which was subject to onion and aphid effects, a diversity effect was found where the cabbages of fully genetically variable microcosms sustained similar final dry mass compared with non-infested microcosms. Our findings provide fresh insights into the use of multi-layered contextual designs that not only allow disentangling the relative effects of genetic variation and modes of interaction, but also help integrate their benefits into pest management in view of companion planting.

The present study was carried out to unveil interactive relevance among consecutive and alternate members of a tritrophic system comprised of sugar beet genotypes, beet armyworm, Spodoptera exigua (Hübner), and its parasitoid, Habrobracon hebetor (Say) using demographic parameters. To do so, H. hebetor was reared on S. exigua fed on 10 sugar beet genotypes, including SB26; SB27; SB29; SB33; SB34; (7112*SB36)*Sh-1-HSF-5; FC220; FC301; SBSI006; and HM 1339RZ in a growth chamber at 25 ± 1 °C, 60 ± 5% RH, and 16:8 (L: D) h photoperiod. The data was analyzed based on the age-stage, two-sex life table theory. Our results revealed high variation in duration of different life stages of H. hebetor on S. exigua reared on different sugar beet genotypes examined. The shortest (10.605 days) and longest (13.721 days) pre-adult period of H. hebetor was on S. exigua reared on SB26 and SB34, respectively. The longest (17.2 days) and shortest adult longevity (7.5 days) was on S. exigua reared on SB26 and SB27, respectively. The highest values of the intrinsic rate of increase (r) (0.209 day−1) and finite rate of increase (λ) (1.233 day−1) were observed on S. exigua reared on SB34 and their lowest values (0.159 and 1.172 day−1, respectively) were recorded on SB27. Resistant and susceptible genotypes to S. exigua, FC301 and (7112*SB36)*Sh-1-HSF-5, respectively, were only genotypes on which H. hebetor had greater and approximately equal r compared with S. exigua. This finding indicates high capability of H. hebetor to be successfully employed against S. exigua on sugar beet genotypes which are extremely different in resistance to this pest.

Greenhouse whitefly, Trialeurodes vaporariorum Westwood, is one of the major insect pests of agricultural crops such as eggplant. Due to various difficulties associated with synthetic pesticides, more environmentally friendly alternative methods are greatly appreciated for controlling pests. In the present study, the induction of resistance was investigated in eggplant using root and foliar application of jasmonic acid, abscisic acid, as well as Nesidiocoris tenuis (Reuter) either individually or in combination against T. vaporariorum. The experiments were carried out under laboratory conditions inside a growth chamber, which was set at 27 ± 2°C, 50 ± 5% relative humidity with a 16 h day length. Our results showed an increase in plant resistance due to the higher immature mortality rates, longer immature periods, lower longevity of adults, and fecundity. In free-choice situation, oviposition on root jasmonic acid (RJA) + N. tenuis and root abscisic acid (RABA) + N. tenuis was similar, but numbers of eggs deposited on these plants were lower than other treatments and control plants. The plant enzyme activity and phenolic content were significantly greater in RJA + N. tenuis and RABA + N. tenuis, intermediate in individual treatments, and the lowest in control plants. Correspondingly, T. vaporariorum longevity, number of eggs produced per female, oviposition preference, all were lowest when the insects fed on these treatments. These findings suggest that the induction of resistance in eggplants with the physiological changes in the host plant leads to a reduction in whitefly damage.

The role of silicon (Si) in alleviating the effects of biotic and abiotic stresses, including defence against insect herbivores, in plants is widely reported. Si defence against insect herbivores is overwhelmingly studied in grasses (especially the cereals), many of which are hyper-accumulators of Si. Despite being neglected, legumes such as soybean (Glycine max) have the capacity to control Si accumulation and benefit from increased Si supply. We tested how Si supplementation via potassium, sodium or calcium silicate affected a soybean pest, the native budworm Helicoverpa punctigera Wallengren (Lepidoptera: Noctuidae). Herbivory reduced leaf biomass similarly in Si-supplemented (+Si) and non-supplemented (–Si) plants (c. 29 and 23%, respectively) relative to herbivore-free plants. Both Si supplementation and herbivory increased leaf Si concentrations. In relative terms, herbivores induced Si uptake by c. 19% in both +Si and –Si plants. All Si treatments reduced H. punctigera relative growth rates (RGR) to a similar extent for potassium (−41%), sodium (−49%) and calcium (−48%) silicate. Moreover, there was a strong negative correlation between Si accumulation in leaves and herbivore RGR. To our knowledge, this is only the second report of Si-based herbivore defence in soybean; the rapid increase in leaf Si following herbivory being indicative of an induced defence. Taken together with the other benefits of Si supplementation of legumes, Si could prove an effective herbivore defence in legumes as well as grasses.

Tribolium castaneum is one of the most economically important insects that damages stored products. The effects of several infested or uninfested raw feed materials (wheat bran, coarse wheat meal, corn feed flour), feed products (compound feed for pigs and for laying hens) and flour mixed with brewer's yeast on the food-searching behaviour of T. castaneum adults were studied in a total of 48 combinations. Preference and olfactometer tests revealed that all the tested uninfested and intraspecific infested substrates were significantly more attractive to T. castaneum than the control (represented by part of an arena or olfactometer arm without substrate). We determined that all infested substrates were 2–9 times more attractive than uninfested in the preference test, while in the olfactometer test, they were 3–8 times more attractive. In comparing the attractiveness of the infested and uninfested substrates, in both tests wheat bran was found to be the most attractive substrate to T. castaneum adults and coarse wheat meal the least. The results of the present study contribute to our knowledge of how raw feed materials and products influence the behaviour of T. castaneum and their susceptibility to infestation, and indicate the possible utilization of wheat bran in monitoring processes of T. castaneum in pest management programmes.

Stictococcus vayssierei is a major pest of root and tuber crops in central Africa. However, data on its ecology are lacking. Here we provide an updated estimate of its distribution with the aim of facilitating the sustainable control of its populations. Surveys conducted in nine countries encompassing 13 ecological regions around the Congo basin showed that African root and tuber scale was present in Cameroon, Central African Republic, Congo, Democratic Republic of Congo, Equatorial Guinea, Gabon and Uganda. It was not found on the sites surveyed in Chad and Nigeria. The pest occurred in the forest and the forest-savannah mosaic as well as in the savannah where it was never recorded before. However, prevalence was higher in the forest (43.1%) where cassava was the most infested crop, compared to the savannah (9.2%) where aroids (cocoyam and taro) were the most infested crops. In the forest habitat, the pest was prevalent in all but two ecological regions: the Congolian swamp forests and the Southern Congolian forest-savanna mosaic. In the savannah habitat, it was restricted to the moist savannah highlands and absent from dry savannahs. The scale was not observed below 277 m asl. Where present, the scale was frequently (87.1% of the sites) attended by the ant Anoplolepis tenella. High densities (>1000 scales per plant) were recorded along the Cameroon–Gabon border. Good regulatory measures within and between countries are required to control the exchange of plant materials and limit its spread. The study provides information for niche modeling and risk mapping.

The oriental armyworm, Mythimna separata is an important crop pest in eastern Asia. Nocturnal insects, including nocturnal moths, have phototactic behavior to an artificial light source. Phototactic behavior in insects is species-specific in response to different wavelengths of light sources. Our previous study showed that green (520 nm) light emitting diode (LED) light resulted in a significantly higher phototactic behavior in M. separata moths compared to the other wavelength LED lights. The goal of the present study is to investigate the influence of green light illumination on biological characteristics of different developmental stages in M. separata. Our results revealed that when different developmental stages of M. separata were exposed to the green light illumination in a dark period, several biological characteristics in all developmental stages except for egg stage were positively changed, but those of F1 generation M. separata which are next generation of the adults exposed to the green light did not significantly change compared with the control level. These findings suggest that green light illumination at night (or dark period) has a positive effect on the development and longevity of M. separata.