Natural Enemy Complex Research Articles

First Report of <i>Tetrastichus howardi</i> (Olliff) and <i>Chelonus formosanus</i> Sonan as parasitoids of fall armyworm, <i>Spodoptera frugiperda</i> (J.E. Smith), in Pakistan

Fall armyworm, Spodoptera frugiperda (J.E. Smith), an invasive agricultural pest, causes substantial economic losses in Pakistan. This study reports the first record of Tetrastichus howardi (Olliff) and Chelonus formosanus Sonan as natural enemies parasitising S. frugiperda within the country. Parasitoids were collected from infested maize fields and identified through morphological analysis. This discovery enhances our understanding of the natural enemy complex associated with S. frugiperda in Pakistan and provides a foundation for investigating their potential as biological control agents. These findings underscore the potential of these parasitoids as components of integrated pest management systems to diminish reliance on chemical insecticides and foster sustainable agricultural practices.

Does weed infestation alter the population density of harmful leafhopper species in second crop maize?

Weed-insect interaction has been studied for decades to determine the role of weeds in insect infestation. This study investigated the impact of weed density on the population density of important leafhopper species (Cicadellidae: Hemiptera) and their egg parasitoid Anagrus atomus (L.) (Hymenoptera: Chalcidoidea) in maize (Zea mays L.) planted as second crop in Şanlıurfa province, Türkiye during 2022 and 2023. Population densities of harmful leafhopper species, i.e., Zyginidia sohrab (Zachvatkin), Empoasca decipiens (Paoli), Asymmetrasca decedens (Paoli), Psammotettix striatus (Linnaeus), and their parasitoid, i.e. A. atomus were monitored by yellow sticky traps (RAL-1016) under weedy and weed-free conditions. Three traps were hung in each experimental unit and the densities of target species were recorded weekly. The population densities of leafhopper species feeding on Sorghum halepense (L.) (Johnsongrass) and the effect of A. atomus on their population density were also determined in weedy treatment. A total 15 maize leaves were taken from both weedy and weed-free treatments, and S. halepense leaf tissues containing leafhopper eggs parasitized by A. atomus were counted weekly. Weed density had non-significant effect on the population density of Z. sohrab during both years. Contrastingly, increasing weed density increased the population density of E. decipiens & A. decedens complex in 2022. Nevertheless, weed density had non-significant effect on the population density of E. decipiens & A. decedens complex during 2023. Weedy treatment recorded higher population density of P. striatus (140 and 100 adults, respectively); however, both weedy and weed-free treatments recorded similar density (125 and 97 adults) during 2023. Weed density proved a significant factor in increasing A. atomus density. A total of 2935 parasitized eggs were recorded from the weedy treatment, whereas 1609 parasitized eggs were recorded from weed-free treatment. Although direct relationship between leafhoppers and weed density remains uncertain, integrated pest management strategies must consider phytophagous insects feeding on weeds at field edges and within fields and the natural enemy complex.

Phenology, population trends and natural enemy complex of Illinoia liriodendri in Spain

Illinoia liriodendri (Monell) (Hemiptera: Aphididae) is an Eastern North American native aphid species that infests ornamental tulip trees, Liriodendron tulipifera L. (Magnoliales: Magnoliaceae), in many localities of Spain and southern Europe. This is a comprehensive three-year study on the biology and ecology of the aphid, where its life cycle, phenology, population dynamic trends, comfort damages, natural enemy complex and its potential to control aphid populations have been investigated for the first time in Europe. The monoecic-holocyclic annual cycle of I. liriodendri has been demonstrated. The highest infestation levels were recorded in May and June, but infestation severity varied among localities. No clear trend regarding the effect of planting site (pit vs. ground) on aphid abundance was observed. A strong positive relationship between the aphid infestation severity and the honeydew dripping was recorded. There was a wide complex of natural enemies associated with the aphid. Coccinellidae were the most abundant predators (< 95%) and showed a positive numerical response to the aphid infestation. Several parasitoid species (mainly Hymenoptera: Aphidiinae and Hymenoptera: Aphelinidae) were found parasitizing I. liriodendri in Spain. The role of natural enemies as agents for controlling the aphid populations is discussed.

Study of Diversity and Abundance Pattern of Natural Enemies Associated with the Mango Mealy Bug (Drosicha mangiferae G) at Malda of West Bengal, India

Background: As a pest, the mango mealy bug (Drosicha mangiferae G) is very important as it ranks second in terms of damage inflicted to the fruit crop. Natural enemies such as predators, parasitoids are considered to be significant deterrent of mango mealy bug. These natural enemies can act as biological control agent which can bring about pest suppression as an important tool of integrated pest management. Therefore, studies of natural enemy complex of mango mealy bug become pertinent. In the current study the available predators, parasitoids of mango mealy bug was surveyed at different regions of Malda. Methods: The predators of mango mealy bugs were studied by sampling mealy bug infested colonies present in the inflorescence and in 20 cm2 area of trunk. Sampling was carried out by visualization of predatory behavior of the entomophagous insects. Parasitoid was studied by observing the emergence of adults from infested mealy bugs in a closed container. Result: Ladybird beetles and Green lacewings were the most abundant predators; their relative abundance was 48.96% and 37.30%. Among the coccinellids, Rodalia amabilis and one unidentified coccinellid were found as dominant. The green lacewing larva, Chrysoparla sp. acted as important predator. Besides Ladybird beetles and Green lacewings, the spiders and bugs were also noticed in the predatory guild. Only one dipteran parasitoid species, Cryptochetum sp. nr. iceryae (Williston) was found to parasitize the mealy bugs. The standardization of mass rearing techniques for the three predators and one parasitoid and their release in the mealy bug infested orchards can bring about efficacious control of this menacing pest.

Egg parasitoid complex of the pine processionary moth in NW Italy

ABSTRACT Investigations on the egg parasitoid complex of the pine processionary moth (PPM), Thaumetopoea pityocampa, were performed in 2020-2022 in seven sites located in NW Italy to determine the parasitoid species composition, seasonal emergence, parasitoid species incidence, and parasitism rate. Furthermore, we examined whether the egg batches parameters and the parasitism rate were influenced by altitude and summer temperatures. A sample of 832 egg batches was collected, each batch consisting on average of 206 ± 5.73 eggs. In total, 35,881 egg parasitoids emerged, mainly represented by four primary species, namely Ooencyrtus pityocampae, Baryscapus servadeii, Anastatus bifasciatus and Trichogramma sp.. Parasitism ranged from 4.27% to 24.41% and the most representative species were O. pityocampae (68.38%) in 2020-2021, and Trichogramma sp. (56.50%) in 2021-2022. The altitude of the sites (808-1303 m a.s.l.) had a negative correlation with all the investigated egg batches parameters (e.g. batch length), and with the parasitism rate by A. bifasciatus and B. servadeii, while a positive correlation was found only for O. pityocampae. The number of days with temperatures above 30°C was positively correlated with parasitism rate for A. bifasciatus and O. pityocampae, and negatively for Trichogramma sp., while no correlation was found with B. servadeii. Since the performance and distribution of the natural enemies is highly dependent on climatic conditions, the regulating effect of parasitoids, reducing PPM population needs to be further investigated, to compare the complex of natural enemies across a wider geographic and climatic range.

Checklist of insect pests and natural enemies associated with groundnut (Arachis hypogaea L.) ecosystem in Anaimalai tract of Tamil Nadu

Fixed and roving surveys were conducted at Coconut Research Station, Aliyarnagar and Anaimalai tract of Coimbatore district, Tamil Nadu to study the insect pests and natural enemy complex of groundnut ecosystem. Results of the study revealed the occurrence of 32 species of insect pests and 13 species of natural enemies. Among the insect pests, only five viz., Helicoverpa armigera, Spodoptera litura, Scirtothrips dorsalis, Empoasca kerri and Aphis craccivora were considered as major pests. Nine insect pests were considered as minor, while 18 were noticed as spot occurrence. The leafminer, Liriomyza trifolii population was noticed only during kharif season. Among the 13 species of natural enemies, coccinellid beetles viz., Coccinella transversalis and Cheilomenes sexmaculatus were dominant.

Ecofriendly Management of Rugose Spiralling Whitefly Aleurodicus rugioperculatus Martin Infesting Coconut

Studies were conducted on the incidence, intensity of infestation, infestation grade index and natural enemy complex of rugose spiralling whitefly (RSW) Aleurodicus rugioperculatus Martin infesting coconut palms so as to evolve ecofriendly IPM. RSW incidence was at peak in June 2018 (38.3%), subsequently declined in December 2018 (20.5%), but later attained peak again in March 2019 (47.5%). The pest intensity also showed increasing trend from January 2018 to June 2019. The mean intensity of infestation and infestation grade index were 29.5% and 1.5 (medium), respectively in 2018-2019. The incidence and intensity significantly reduced from 75.5 to 37.7% and 85.7 to 42.9%, respectively on palms treated with ecofriendly IPM practices in 2018-19. Nut yield and net return were also found more in synergy with maximum parasitism (78.5%) by the aphelinid parasitoid Encarsia guadeloupae Viggiani observed on palms treated with ecofriendly IPM practices.

Incidence of invasive mealybugs, Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae) on Gymnema sylvestre (R. Br) and its natural enemies in the semi-arid region of India

The invasive mealybugs, Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams & Granara de Willink (Hemiptera: Pseudococcidae) are causing significant damage to Gymnema sylvestre in the semi-arid region. This study highlights the nature of the damage, severity of mealy bugs and natural enemy complex association. The severity of infestation was maximum during 23rd and 22nd Standard Meteorological Weeks (SMW) (3.67 and 3.66) of 2019 and 2020, respectively. The pooled data of both the years revealed that temperature has a significant positive correlation and rainfall has a negative correlation towards the severity of the pest incidence with respective r-values of 0.678** and −0.05. A total of 19 different natural enemies identified belong to 7 families of 4 insect orders. Cheilomenes sexmaculata (Fabricius) was the most common predator and among the parasitoids, three species of primary parasitoids viz., Aenasius arizonensis (Girault) and Pseudleptomastix mexicana Noyes & Schauff (Hymenoptera: Encyrtidae) were more abundant. Besides, six species are hyperparasitoids viz., Aprostocetus sp, Chartocerus sp., Cheiloneurus sp., Homalotylus turkmenicus Myartseva, Marietta leopardina Motschulsky and Prochiloneurus sp. were recorded from primary parasitoids.

Exclusion netting affects apple arthropod communities

Exclusion cages can quantitatively demonstrate the value of natural enemies and the biological control services they provide. Currently, in Washington State, enclosing orchards in netting is being evaluated as a pest control method, but these enclosures may also serve as an exclusion cage to natural enemies, thereby disrupting biological control. To test the effects of net enclosures on apple arthropod communities, we conducted a two-year study comparing apple herbivore, predator, and parasitoid densities in caged and uncaged plots (both receiving insecticides) to an untreated check. Effects on the various groups were influenced by size and motility. Densities of larger motile arthropods, including codling moth (Cydia pomonella (L.)), chrysopids, and syrphids, were lower in the caged plots, demonstrating exclusion. Woolly apple aphid (Eriosoma lanigerum (Hausmann)) and its parasitoid Aphelinus mali (Haldeman) densities in the caged plots were over 100-fold greater and 5-fold greater, respectively, than the other treatments. European earwig (Forficula auricularia (L.)), a generalist predator, was more abundant in the caged plots in 2016 but not in 2017. Spider mites were more abundant in the cage treatments for both years, while predatory mites had higher densities in the cages in 2017 only. These outcomes show that net enclosures change the composition of apple arthropod communities through exclusion of certain herbivores and natural enemies. In the case of some pest herbivores (e.g., codling moth), this exclusion is beneficial, but in the case of predators, it is detrimental. This study further demonstrated that exclusion of only part of the natural enemy complex may be sufficient to cause herbivore outbreaks.

New host plants, natural enemy complex and newly distributed potential areas of exotic spiralling whitefly (Hemiptera: Aleyrodidae) in India

New host plants, natural enemy complex and newly distributed potential areas of exotic spiralling whitefly (Hemiptera: Aleyrodidae) in India

Successful Completion of an International Project of the Department of Natural Sciences at New Bulgarian University

The paper presents the results of a successfully completed international project of the Department of Natural Sciences titled “Monitoring and identification of the entomopathogenic fungus Entomophaga maimaiga in Lymantria dispar populations” and funded by the National Research Fund in 2017-2019. Investigating the distribution of E. maimaiga in Austria and Bulgaria in 2018-2019 shows that the pathogen has expanded its range to the west and reached Lower Austria. E. maimaiga has been identified in Bulgaria as well and has become part of the natural enemy complex of L. dispar.

Influence of the site of oviposition on the level of egg parasitism in the corn leafhopper, Dalbulus maidis (Hemiptera: Cicadellidae).

The corn leafhopper Dalbulus maidis (DeLong) (Hemiptera: Cicadellidae), transmits three important plant pathogens that adversely affect corn crop and ranges from the USA to Argentina. The vector has a rich natural enemy complex that generates high levels of parasitism, but its populations are persistent and prevalent. We characterized the oviposition sites of D. maidis on young corn plants in order to verify the hypothesis that the vector has an oviposition strategy for mitigating parasitism. Oviposition locations on plants were assessed in the laboratory and eggs within corn plants were exposed to natural parasitism in a cornfield. Eggs were located mostly laid in the unfolded leaves and were attacked by five parasitoid species. Parasitism was significantly affected by the class of leaf and the position of the egg in the leaf. Anagrus virlai Triapitsyn was the most abundant parasitoid species, which emerged significantly higher in the basal blade than other species. Our results suggest that leafhoppers minimize egg parasitism by laying their eggs within concealed locations on the plant.

Seasonal Phenology of the Major Insect Pests of Quinoa (Chenopodium quinoa Willd.) and Their Natural Enemies in a Traditional Zone and Two New Production Zones of Peru

Over the last decade, the sown area of quinoa (Chenopodium quinoa Willd.) has been increasingly expanding in Peru, and new production fields have emerged, stretching from the Andes to coastal areas. The fields at low altitudes have the potential to produce higher yields than those in the highlands. This study investigated the occurrence of insect pests and the natural enemies of quinoa in a traditional production zone, San Lorenzo (in the Andes), and in two new zones at lower altitudes, La Molina (on the coast) and Majes (in the “Maritime Yunga” ecoregion), by plant sampling and pitfall trapping. Our data indicated that the pest pressure in quinoa was higher at lower elevations than in the highlands. The major insect pest infesting quinoa at high densities in San Lorenzo was Eurysacca melanocampta; in La Molina, the major pests were E. melanocampta, Macrosiphum euphorbiae and Liriomyza huidobrensis; and in Majes, Frankliniella occidentalis was the most abundant pest. The natural enemy complex played an important role in controlling M. euphorbiae and L. huidobrensis by preventing pest resurgence. The findings of this study may assist quinoa producers (from the Andes and from regions at lower altitudes) in establishing better farming practices in the framework of integrated pest management.

Evaluation of Various Pest Management Modules Against Rice Yellow Stemborer, Scirphopaga incertulas (Walker) (Crambidae: Lepidoptera)

Background: Globally, rice yellow stem borer alone causes yield losses of 10 m t accounting for 50 per cent of all insecticides usage in the rice field farmers depend upon a plenty of insecticide applications, even though a lot of insecticide applications are not effectual (Sarwar et al., 2005). The over- reliance on use of chemicals to manage this pest had lead to numerous undesirable consequences like disrupting natural enemy complexes, secondary pest outbreaks, pest resurgence, development of insecticide resistance and environmental pollution. Keeping in view the deleterious effects of chemical pesticides, there is a need to evaluate alternate methods or integrated methods to manage the rice stem borer effectively without any menace to the ecological niche. Hence, a research trial was conducted to evaluate the efficacy of various pest management modules against rice stem borer in comparison to farmers practice and sole chemical control, besides in concern to yield and cost economics. Methods: The field efficacy of various pest management modules viz., non-chemical based, non-chemical + biorational methods, chemical-based, IPM module and farmers practice against rice yellow stem borer were evaluated during the wet season and dry seasons of 2016 and 2017. The experimental was laid in a net area of 10 m x 20 m each plot laid in Randomized Block Design which comprised of five treatments (modules) with four replications. The incidence of rice yellow stem borer (YSB) in various modules in terms of percent dead hearts (% DH) during tillering stage and percent white ears (%WE) during maturing stage were recorded. Result: It was evident from the pooled mean data that among various modules, the least per cent dead hearts (2.68 and 2.56% DH ) and white ears (2.79 and 2.31% WE) were registered in IPM based module followed by farmers practice (2.31 and 2.32% dead hearts and 3.92 and 4.77% white ears) and chemical-l based module (2.90 and 4.24% dead hearts and 5.59 and 5.18% white ears) as against highest incidence in non- chemical (13.78 and 13.7% dead hearts; 18.24 and 17.94% white ears) and non- chemical + bio rational (11.40 and 9.88% dead hearts; 13.09 and 11.25% white ears ) based modules during the wet season and dry season, respectively.

Control of the white mango scale Aulacaspis tubercularis (Hemiptera: Sternorrhyncha: Diaspididae) with systemic soil drenching insecticides and pruning in greater than ten years old mangos in western Ethiopia

The white mango scale insect (WMS), Aulacaspis tubercularis Newstead, 1906 is a key pest of mango in Ethiopia, which has been spreading throughout the country since its introduction in 2010. Evaluation of the efficacy of two systemic soil drenching insecticides (thiamethoxam 25 % WG and imidacloprid 35 % SC) independently, and in combination with tree management (pruning) for the cont­rol of the WMS was conducted under field conditions in western Ethiopia in two locations in 2018 and 2019. Randomized complete block designs with three replications were used for the experiments. In the first site, all treatments resulted in scale populations that were significantly lower than the control (1086 crawlers and females per leaf). Thiamethoxam 25 % WG at 12 g/tree + pruning resulted in the lowest number of the WMS after the second treatment (43.5 per leaf) followed by thiamethoxam 25 % WG at 18 g/tree + pruning, which was statistically similar. In the second site, imidacloprid 35 % SC + thiamethoxam 25 % WG at 18 g/tree + pruning, resulted in the lowest mean number of the WMS (31.1 per leaf) followed by thiamethoxam 25 % WG at 12 g/tree + pruning (61.4 per leaf). This treatment also gave the highest percentage reduction in number of the WMS compared to the WMS counting before treatment application. This study has shown that use of systemic insecticides and pruning are promising control tactics for the WMS. Cost implications and effects of the insecticides on the natural enemy complex and residual toxicity in fruits need to be evaluated. To cite: Belay Habtegebriel, Dawit Melisie, Hunde Kidane, Teshale Daba & Ferdu Azerefegn. 2020. Control of the white mango scale Aulacaspis tubercularis (Hemiptera: Sternorrhyncha: Diaspididae) with systemic soil drenching insecticides and pruning in greater than ten years old mangos in western Ethiopia. Israel Journal of Entomology 50(1): 65–73. http://doi.org/10.5281/zenodo.3987792http://zoobank.org/References/8FA7BF70-B678-420B-9E11-3D87C8F16C76

Natural mortality of invasive fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) in maize agroecosystems of northeast India

Invasive fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) is a pest of American origin that has recently invaded Asian countries, including India. After causing huge losses in the Africa and Asia, the FAW is now affecting large areas of India. Indigenous natural enemies of related pest species are the first defense against invasive pests and understanding their role in population suppression of invasive pests is a first step towards the development of a comprehensive management program. Therefore, we studied the natural enemy complex responsible for natural mortality of FAW in northeast India. Various locations were surveyed across five major districts of Meghalaya state, where more than 26 species of natural enemies were found attacking FAW. A total of 56.6% to 73.1% of larvae were found to be either parasitized or infected with naturally occurring entomopathogens. Species richness and diversity of predators were determined in maize fields at different locations. Values of Menhinick's species richness index (DMn) varied from 0.23 to 0.31 and Shannon-Wiener index (H) ranged from 2.16 to 2.6 across various locations. The Simpson Index (D) indicated high predator diversity in maize fields. The entomopathogenic fungus, Metarhizium rileyi (Farlow) Samson and the baculovirus, SpfrNPV were observed to be the dominant mortality factors throughout the season, responsible for >50% mortality of FAW larvae. This investigation demonstrated that indigenous natural enemies of related noctuid species can widen their host range and successfully adopt the invasive FAW as a novel host/prey in invaded regions. Therefore, conservation of such biocontrol agents could be vital for mitigating FAW damage in maize agroecosystems.

Prospects for classical biological control of Marchalina hellenica in Australia

The giant pine scale, Marchalina hellenica Gennadius (Hemiptera: Marchalinidae), is a sap-sucking insect native to South-East Europe that was recently introduced in Australia where it threatens the pine forestry industry. To initiate a classical biological control programme, a literature review and field surveys were carried out in Greece to investigate the natural enemy complex of the scale. While no parasitoids were found, M. hellenica was attacked by several predators, most notably Neoleucopis kartliana Tanasijtshuk (Diptera: Chamaemyiidae). N. kartliana was present at all sites investigated and is presumably specific to Marchalina. This highlights its potential as a biological control agent for M. hellenica. This predatory fly has already been used to control M. hellenica on the Italian island of Ischia. Interestingly, molecular analyses of Greek samples revealed other Chamaemyiidae predatory flies that can be potentially included in the Australian classical biological control programme of M. hellenica.

Description of two new Quadrastichus (Hymenoptera: Eulophidae) reared from Litchiomyia chinensis (Diptera: Cecidomyiidae) on commercial lychee (Litchi chinensis; Sapindaceae) in Taiwan

ABSTRACT The lychee gall midge, Litchiomyia chinensis Yang and Luo (Diptera: Cecidomyiidae), invaded Taiwan in 2008. This fly induces blister-galls on the leaves of lychee, Litchi chinensis Sonn (Sapindaceae), and causes significant yield losses. At present, its natural enemy complex is largely undocumented; thus, the overall aim of ongoing research is to investigate the natural enemies on L. chinensis in different areas and seasons in Taiwan. We describe two species that parasitise this gall midge: Quadrastichus lasallei, sp. n. and Quadrastichus johnlasallei, sp. n. that demonstrate biocontrol potential of this pest. http://www.zoobank.org/urn:lsid:zoobank.org:act:A5E93071-D935-4F60-BCF9-225C50389ABF http://www.zoobank.org/urn:lsid:zoobank.org:act:261FC598-03CC-44A1-9379-F665B2DF0AA0

Prey of the Green Lynx Spiders (Peucetia Viridana)

Spiders are important constituents of the natural enemy complex of pests in agricultural fields. Spiders are usually ankles that hunt and eat insects. Although they have a variety of foods, Peucetia viridana eat harmful insects. Spiders are important constituents of the natural enemy complex of pests in agricultural fields. However, despite its known importance in agriculture, its contribution to pest control is still largely unnoticed.

Bioecology, damage and management of bud worm, Hendecasis duplifascialisis Hampson: An overview

Jasminum multiflorum, a non-fragrant flower species is mainly grown by small and marginal farmers in southern districts of Karnataka. The budworm, Hendecasis duplifascialisis Hampson has been posing a serious threat to jasmine cultivation in recent years. The species J. multiflorum is more prone to the bud worm attack. The total life cycle of the bud worm on J. multiflorum was found to be 27 ± 1.82 days. The natural enemy complex of bud worm includes the coccinellid and neuropteran predators, parasitoids like Bracon sp., Phanerotoma hendecasiella, Brachymeria sp. and Xanthopimpla sp. The green labled chemicals like chlorantraniliprole 18.5 SC, flubendiamide 480 SC, and spinosad 45 SC were more effective against bud worm and at the same time these chemicals are comparatively safe for those working every day in jasmine gardens.