scholarly journals Lethal, Sublethal And Transgenerational Effects of Insecticides Labeled For Cotton On Immature Trichogramma Pretiosum

2021 ◽  
Author(s):  
Mariana Abreu Costa ◽  
Elizeu Sá Farias ◽  
Eliana Donizete Andrade ◽  
Vinícius Castro Carvalho ◽  
Geraldo Andrade Carvalho
Keyword(s):  
Sex Ratio ◽  
Adult Emergence ◽  
Positive Control ◽  
Egg Parasitoid ◽  
Biological Traits ◽  
Trichogramma Pretiosum ◽  
Transgenerational Effects ◽  
Female Survival ◽  
Chemical Groups ◽  
Lepidopteran Pest

Abstract The egg parasitoid Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) regulates lepidopteran pest populations in cotton crops. However, cotton harbors dozens of pests, and growers rely on multiple insecticide applications to manage these damaging organisms. A harmonious integration of control tactics is required for proper pest management, and the use of selective insecticides (i.e., those promoting effective pest control while causing little impact on natural enemies) fits within this scope. This study aimed to assess the lethal, sublethal and transgenerational effects of insecticides from varying chemical groups on T. pretiosum. The insecticides were sprayed on parasitized host [Ephestia kuehniella (Zeller)] eggs with developing T. pretiosum stages (egg-larva, prepupa and pupa), and biological traits were assessed following adult emergence. Overall, pupae were more susceptible to the insecticides. We found thiodicarb and chlorfenapyr to reduce F0 adult emergence in rates comparable to the positive control (methomyl). Adult F0 deformation was the highest on flupyradifurone-treated organisms, and both the F0 parasitism rate and female survival were reduced by the insecticides (except for teflubenzuron). The sex ratio was affected by thiodicarb and flupyradifurone. Transgenerational effects occurred on adult emergence, which was reduced on the offspring (F1) of thiodicarb-, chlorfenapyr-, and flupyradifurone-treated T. pretiosum. In addition, thiodicarb lessened the F1 sex ratio. Combined, these results indicate that teflubenzuron is the safest insecticide; the other insecticides (especially thiodicarb and chlorfenapyr) are non-selective to T. pretiosum. Field and semifield studies are required to confirm the harmfulness of thiodicarb and chlorfenapyr towards T. pretiosum.

scholarly journals Taxonomic identification and biological traits of Platystethynium triclavatum (Donev & Huber, 2002), comb. n. (Hymenoptera, Mymaridae), a newly recorded egg parasitoid of the Italian endemic pest Barbitistes vicetinus (Orthoptera, Tettigoniidae)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9667
Author(s):  
Giacomo Ortis ◽  
Serguei V. Triapitsyn ◽  
Giacomo Cavaletto ◽  
Isabel Martinez-Sañudo ◽  
Luca Mazzon
Keyword(s):  
Sex Ratio ◽  
Egg Parasitoid ◽  
Biological Traits ◽  
Taxonomic Identification ◽  
Forest Pest ◽  
Veneto Region ◽  
Northeastern Italy ◽  
Bush Cricket

The little known fairyfly (Hymenoptera, Mymaridae), Platystethynium (Platystethynium) triclavatum (Donev & Huber, 2002), comb. n. from Pseudocleruchus Donev & Huber, 2002, is newly recorded as an egg parasitoid of Barbitistes vicetinus Galvagni & Fontana, 1993 (Orthoptera, Tettigoniidae). This bush-cricket is endemic to northeastern Italy (mainly Euganean Hills of Veneto Region), where it has recently become an economically significant agricultural and forest pest. Data on discovery, distribution, and some remarkable biological traits of this gregarious egg parasitoid are presented. Its identification and availability of many well-preserved fresh specimens have made possible to re-define Pseudocleruchus Donev & Huber, 2002 syn. n., with type and the only described species Pseudocleruchus triclavatus Donev & Huber, 2002, as a synonym of Platystethynium Ogloblin, 1946 and its nominate subgenus, P. (Platystethynium), and also to describe the brachypterous male of P. (Platystethynium) triclavatum. It is the first known male for the entire genus. Enlarged mandibles of the megacephalous males are used to chew holes in the hard chorion of the host egg, allowing fully winged females, whose mandibles are strongly reduced and do not cross over, to emerge after mating with the males inside it. Up to 136 individual parasitoids (about 77 on average) can hatch from a single egg of B. vicetinus, with their sex ratio being strongly female biased (80–97% females per egg).

Efeito de Óleos Essenciais Sobre Estágios Imaturos de Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae)

2017 ◽  
Vol 21 (2) ◽  
pp. 80
Author(s):  
Douglas Silva Parreira ◽  
Francisco Andreas Rodrigues Dimaté ◽  
Lorena Duarte Batista ◽  
Humberto Corrêa Bomfim Ribeiro ◽  
Rafael Eugênio Guanabens ◽  
...  
Keyword(s):  
Allium Sativum ◽  
Positive Control ◽  
Egg Parasitoid ◽  
Negative Control ◽  
Mentha Piperita ◽  
Trichogramma Pretiosum ◽  
Insecticidal Effect ◽  
Lambda Cyhalothrin ◽  
Class 1 ◽  
Glass Tubes

O manejo integrado de pragas prioriza o uso de táticas de controle, que reduzam o impacto ambiental causado pelo uso maciço e incorreto de produtos químicos sintéticos. A preservação e liberação de inimigos naturais, nos campos agrícolas, e a descoberta de novas moléculas com efeito inseticida extraídas de espécies vegetais têm obtido bons resultados no controle de pragas. Porém, o efeito do uso conjunto dessas táticas de controle é pouco explorado. O objetivo desse trabalho foi avaliar o efeito de óleos botânicos sobre os estágios imaturos de Trichogramma pretiosum em laboratório. Ovos de A. kuehniella colados em cartelas de papel foram expostos a fêmeas, previamente individualizadas, em tubos de vidro durante 24h. Decorrido esse período, os ovos supostamente parasitados foram mergulhados em soluções de óleo essenciais (Allium sativum, Mentha piperita e Syzygium aromarticum), inseticida lambda-cialotrina (testemunha positiva) e etanol (testemunha negativa) durante 5 segundos, secos à sombra por trinta minutos e colocados em tubos de vidro. Os tubos foram mantidos em câmara climatizada a 25 ± 2°C, 70 ± 10% de UR e fotoperíodo de 12 h. Os óleos essenciais de A. sativum, M. piperita and S. aromarticum e o inseticida lambda-cialotrina foram levemente tóxicos (classe 2) a pupas de T. pretiosum. A razão sexual não foi afeta por nenhum composto classificando-os como inócuo (classe 1). Os óleos e o inseticida testado podem ser utilizados em associação com T. pretiosum, desde que os protocolos de seletividade ecológica sejam respeitados.Palavras-chave: Produtos naturais, parasitóide de ovos, seletividade.AbstractIntegrated pest management prioritizes the use of control tactics that reduce the environmental impact caused by the massive and incorrect use of synthetic chemicals. The preservation and release of natural enemies in agricultural fields and the discovery of new molecules with insecticidal effect extracted from plant species, have obtained good results in pest control. However, the effect to the use in joint of these control tactics is little explored. The objective of this work was to evaluate the effect of botanical oils on the immature stages of Trichogramma pretiosum in the laboratory. Eggs of Anticarsia kuehniella glued on paper plates were exposed to previously individualized females in glass tubes for 24 hours. After this period, the supposedly parasitized eggs were immersed in essential oil solutions (Allium sativum, Mentha piperita and Syzygium aromarticum), lambda-cyhalothrin insecticide (positive control) and ethanol (negative control) for 5 seconds, dried in the shade for 30 minutes and placed in glass tubes. The tubes were kept in an air-conditioned chamber at 25 ± 2°C, 70 ± 10% HR and 12-h photoperiod. The essential oils of A. sativum, M. piperita and S. aromarticum and lambda-cyhalothrin insecticide were slightly toxic (class 2) to T. pretiosum pupae. The sex ratio was not affected by any compound by classifying them as innocuous (class 1). The oils and insecticide tested can be used in association with T. pretiosum, since the ecological selectivity protocols are respected.Keywords: Natural products, egg parasitoid, selectivity.

scholarly journals High Tolerance of Trichogramma Pretiosum (Hymenoptera: Trichogrammatidae) to the Mixture of the Herbicides Nicosulfuron Plus Atrazine

2020 ◽  
Author(s):  
Germano Leão Demolin Leite ◽  
João Marcos Batista Cordeiro ◽  
Leonardo David Tuffi Santos ◽  
Wagner de Souza Tavares ◽  
Alexandre Igor de Azevedo Pereira ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Free Choice ◽  
Integrated Control ◽  
The Other ◽  
Choice Test ◽  
Trichogramma Pretiosum ◽  
Maize Crop ◽  
Trichogramma Brasiliensis ◽  
Herbicide Mixture ◽  
Lepidopteran Pest

Abstract Background: Maize, Zea mays (Poaceae), is one of the most important crops in the world, but defoliating caterpillars (Lepidoptera) and weeds can reduce the productivity of this plant. The control of weeds in the maize crop in Brazil is mainly accomplished with nicosulfuron- and atrazine-based herbicides, and of lepidopteran pest eggs with use of several species of Trichogrammatidae (Hymenoptera) parasitoids released. The objective of this study was to evaluate the rates of parasitism and emergence of females and the sex ratio (%) of 10 Trichogrammatidae species, in a free-choice test, submitted to a mixture of the herbicides Sanson 40 SC® (a.i. nicosulfuron; dose: 30 g.ha–1) + Gesaprim 500 Ciba-Geigy® (a.i. atrazine; dose: 1500 g.ha–1) in the laboratory.Results: The parasitism rate (%) of Trichogramma acacioi Brun, Moraes & Soares, Trichogrammatoidea annulata de Santis, Trichogramma atopovirilia Oatman & Platner, Trichogramma bennetti Nagaraja & Nagarkatti, Trichogramma brunni Nagaraja, Trichogramma brasiliensis Ashmead, Trichogramma demoraesi Nagaraja, Trichogramma galloi Zucchi, and Trichogramma soaresi Nagaraja was lower with the herbicide mixture of nicosulfuron + atrazine than the control and, therefore, this mixture was considered to be slightly harmful (i.e., class II of the International Organization for Biological and Integrated Control) to these parasitoids. This solution reduced the emergence rate (%) of female T. acacioi, T. annulata, T. atopovirilia, T. bruni, T. brasiliensis, T. demoraesi, T. galloi, and T. soaresi, being classified as harmless to T. soaresi, moderately harmful to T. galloi and slightly harmful to the other species. The herbicide mixture of nicosulfuron + atrazine reduced the sex ratio of T. acacioi, T. atopovirilia, T. bruni, T. demoraesi, T. galloi, and T. soaresi, being classified as harmless to T. annulata and T. brasiliensis, and slightly harmful to the other species.Conclusions: The biological parameters (i.e., rates of parasitism and emergence and the sex ratio) of T. pretiosum, followed by T. bennetti, T. annulata and T. brasiliensis were the least affected by the herbicide mixture. These species should be chosen for release, on pieces of paperboard with parasitized E. kuehniella eggs, in crops together with the application of nicosulfuron + atrazine.

scholarly journals Compatibility between Entomopathogenic Fungi and Egg Parasitoids (Trichogrammatidae): A Laboratory Study for Their Combined Use to Control Duponchelia fovealis

Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 630
Author(s):  
Emily Silva Araujo ◽  
Alex S. Poltronieri ◽  
Carolina G. Poitevin ◽  
José Manuel Mirás-Avalos ◽  
Maria Aparecida Cassilha Zawadneak ◽  
...  
Keyword(s):  
Biological Control ◽  
Entomopathogenic Fungi ◽  
Control Strategies ◽  
Adult Emergence ◽  
Biological Traits ◽  
Trichogramma Pretiosum ◽  
Biological Control Agents ◽  
Parasitism Rate ◽  
Trichogramma Species ◽  
Combined Use

The European pepper moth, Duponchelia fovealis (Lepidoptera: Crambidae), is a key pest in strawberry production. Entomopathogenic fungi (EF) and parasitoids of the Trichogrammatidae family are effective biological control agents of this pest with the potential to be used jointly for improved efficacy. This study aims to evaluate the susceptibility of Trichogramma atopovirilia and Trichogramma pretiosum to two Beauveria bassiana strains (B2 and B3) and two commercial bioinsecticides (Bovemax® and Methamax®) by applying them to D. fovealis eggs in pre- and post-parasitism periods. Pre-parasitism application of B2 and B3 did not affect the percentage of D. fovealis eggs parasitized by either Trichogramma species, except in the case of T. atopovirilia when eggs were sprayed with B3 at 1.5 × 105 conidia mL−1 (16.7% less than the control). In contrast, eggs sprayed with 1.5 × 108 conidia mL−1 of the commercial bioinsecticides were not parasitized by any Trichogramma species. Overall, the EF tested reduced the parasitism rate, adult emergence, and longevity of Trichogramma adults by less than 30% in all cases. The adverse effects of the B. bassiana strains and commercial products on the biological traits of both Trichogramma species were minimal, meaning that these agents can be used jointly in D. fovealis control strategies.

scholarly journals Selectivity of registered pesticides for the corn crop on immature stages of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae)

2019 ◽  
Vol 43 ◽  
Author(s):  
Tatiele Pereira dos Santos ◽  
Claubert Wagner Guimarães de Menezes ◽  
Carlos Henrique Batista ◽  
Eliane Souza Gomes Brito ◽  
Wagner de Souza Tavares ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
Zea Mays L ◽  
Positive Control ◽  
Egg Parasitoid ◽  
Negative Control ◽  
Trichogramma Pretiosum ◽  
Anagasta Kuehniella ◽  
Lepidoptera Pyralidae ◽  
Low Toxicity ◽  
Chemical Products

ABSTRACT Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) is an egg parasitoid of lepidopteran pests in corn, Zea mays L. (Poaceae), in Brazil. Chemical products used in agriculture can be toxic to this biocontrol agent. The objective of the present study was to evaluate the longevity, parasitism and emergence of T. pretiosum parasitizing Mediterranean flour moth, Anagasta kuehniella Zeller, 1879 (Lepidoptera: Pyralidae), eggs treated with herbicide solutions with the active ingredients (chemical group) atrazine (triazines), paraquat dichloride (bipyridylium) and nicosulfuron (sulfonylurea). Pure distilled water was used as a negative control, and a solution of a product with λ-cyhalothrin + thiamethoxam (pyrethroid + neonicotinoid, respectively) was used as the positive control. The experimental design was completely randomized, with five treatments and 10 replicates. Anagasta kuehniella eggs were stored for two periods after treatment, 24 and 48 hours. These eggs were subjected to parasitism for two subjecting periods, 24 and 48 hours. The results were analysed statistically and classified according to the International Organization for Biological Control (IOBC). Atrazine and nicosulfuron reduced the longevity of T. pretiosum females. Nicosulfuron and the combination λ-cyhalothrin + thiamethoxam reduced the parasitism and emergence of this natural enemy. The paraquat dichloride-based herbicide was the least toxic and therefore represents a potential option for controlling weeds with low toxicity to the T. pretiosum parasitoid.

scholarly journals COMPATIBILIDADE DE MILHO TRANSGÊNICO COM O PARASITOIDE Trichogramma pretiosum

2017 ◽  
Vol 16 (1) ◽  
pp. 43 ◽  
Author(s):  
DANIEL SPAGNOL ◽  
ANDERSON DIONEI GRÜTZMACHER ◽  
RODOLFO VARGAS CASTILHOS ◽  
RAFAEL ANTÔNIO PASINI ◽  
RONALDO ZANTEDESCHI ◽  
...  
Keyword(s):  
Biological Control ◽  
Bacillus Thuringiensis ◽  
Sex Ratio ◽  
Egg Parasitoid ◽  
Transgenic Corn ◽  
Trichogramma Pretiosum ◽  
Corn Hybrids ◽  
Anagasta Kuehniella ◽  
Bt Toxins ◽  
Total Parasitism

RESUMO - Plantas de milho transgênicas que expressam toxinas da bactéria Bacillus thuringiensis (Bt) são uma alternativa para o controle de insetos-praga na cultura. No entanto, estas toxinas podem ser encontradas no pólen do milho, e organismos não alvo, como os inimigos naturais, podem ser prejudicados. Assim, o objetivo deste trabalho foi avaliar o efeito do pólen de três híbridos de milho transgênicos sobre parâmetros biológicos de adultos do parasitoide de ovos Trichogramma pretiosum em condições laboratoriais. Fêmeas recém-emergidas de T. pretiosum foram individualizadas em tubos de Duran contendo como alimento mel acrescido do pólen dos híbridos de milho transgênico AG 8011 YG (Cry1Ab), AS 1551 VT PRO (Cry1A. 105 + Cry 2Ab2) e Status Viptera (Vip3Aa20), e de seus respectivos isogênicos convencionais. Diariamente, foram ofertados, em cada tubo, ovos de Anagasta kuehniella para parasitismo. Os parâmetros avaliados foram: longevidade das fêmeas expostas ao pólen, taxa de parasitismo total, taxa de emergência e razão sexual da progênie. Os híbridos transgênicos: AG 8011 YG (Cry1Ab), AS 1551 VT PRO (Cry1A. 105 + Cry 2Ab2) e Status Viptera (Vip3Aa20), bem como seus isogênicos convencionais, não causaram efeitos deletérios sobre a longevidade e capacidade de parasitismo das fêmeas de T. pretiosum expostas aos respectivos pólens. A emergência e razão sexual da progênie também não foram negativamente afetadas, possibilitando assim a compatibilização dos transgênicos avaliados com o controle biológico natural e aplicado exercido por este parasitoide.Palavras-chave: Bacillus thuringiensis, transgenia, manejo integrado de pragas, controle biológico, Zea mays.COMPATIBILITY OF TRANSGENIC CORN WITH THE PARASITOID Trichogramma pretiosumABSTRACT - Transgenic corn expressing Bacillus thuringiensis (Bt) toxins is an alternative for pest control in corn fields. However, some non-target organisms such as natural enemies can be impaired by corn pollen containing toxins. Therefore, the aim of this work was to evaluate the effect of the pollen from three transgenic corn varieties on biological parameters of the egg parasitoid Trichogramma pretiosum under laboratorial conditions. Emerged females of T. pretiosum were placed into Duran tubes and fed with honey + pollen of corn hybrids AG 8011 YG (Cry1Ab), AS 1551 VT PRO (Cry1A. 105 + Cry 2Ab2) and Status Viptera (Vip3Aa20), as well as their respective isogenic. Daily, eggs of Anagasta kuehniella were offered in each tube for parasitism. The parameters evaluated were longevity of females exposed to pollen, total parasitism, progeny emergency and sex ratio. The transgenic hybrids AG 8011 YG (Cry1Ab), AS 1551 VT PRO (Cry1A. 105 + Cry 2Ab2), Status Viptera (Vip3Aa20) and their isogenic showed no deleterious effect on longevity and parasitism capacity of T. pretiosum females exposed to respective pollen. Emergency and sex ratio from progeny were also not adversely affected, thus enabling the compatibility of the evaluated transgenic with biological control by this parasitoid.  Keywords: Bacillus thuringiensis, transgenes, integrated pest management, biological control, Zea mays.

scholarly journals Is High Whitefly Abundance on Cassava in Sub-Saharan Africa Driven by Biological Traits of a Specific, Cryptic Bemisia tabaci Species?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal
Keyword(s):  
Food Security ◽  
Bemisia Tabaci ◽  
Development Time ◽  
Adult Emergence ◽  
Sub Saharan Africa ◽  
Biological Traits ◽  
Population Development ◽  
Species Classification ◽  
First Instar ◽  
Sub Saharan

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.

Immature development and adult eclosion of Ufens principalis Owen (Hymenoptera: Trichogrammatidae), an egg parasitoid of Homalodisca spp. (Hemiptera: Cicadellidae) in southern California

2009 ◽  
Vol 100 (4) ◽  
pp. 467-479 ◽  
Author(s):  
A.K. Al-Wahaibi ◽  
J.G. Morse
Keyword(s):  
Southern California ◽  
Negative Relationship ◽  
Adult Emergence ◽  
Egg Parasitoid ◽  
Adult Size ◽  
Adult Eclosion ◽  
Late Night ◽  
Immature Development ◽  
Yellow Orange ◽  
Theoretical Minimum

AbstractThe biology of the immature stages and adult eclosion of Ufens principalis Owen, an important parasitoid of Homalodisca eggs in southern California, were studied. The duration of the egg, larval and pupal stages at 26.7°C were 0–1, 7 and 9 days, respectively. Sacciform larvae, which developed gregariously within host eggs, were motile until about five days of age, and then became sessile. Parasitized host eggs changed from whitish and soft when freshly-laid to yellow-orange and hard at five days and older. This change was accompanied by formation of septal walls separating the mature larvae and pupae. The rate of immature development had a strong positive linear relationship (R2=0.853, n=98) with temperatures in the range of 20.0–30.3°C. The theoretical minimum threshold for immature development was 13.5°C, and the required heat units were 241.0 degree-days. Adult eclosion from host eggs occurred mostly (85%) on the first two days of emergence. Although most females emerged during the morning hours (0600–1200 h), males tended to emerge earlier than females with equal emergence during the morning and late night hours (2400–0600 h). The rate of successful adult emergence was high (88%). The ratio of eclosed adults to the number of exit holes was 1.18, indicating that most adults tended to independently cut their exit holes. The number of exit holes had a strong negative relationship (R2=0.711, n=125) with exit hole size, suggesting that larger numbers of developing immatures per host egg result in an overall decrease in adult size.

scholarly journals Transgenerational effects modulate density-dependent prophylactic resistance to viral infection in a lepidopteran pest

2015 ◽  
Vol 11 (3) ◽  
pp. 20150012 ◽  
Author(s):  
Kenneth Wilson ◽  
Robert I. Graham
Keyword(s):  
Disease Resistance ◽  
Survival Rates ◽  
Post Challenge ◽  
Transgenerational Effects ◽  
Density Dependent ◽  
Offspring Fitness ◽  
Rearing Density ◽  
Lepidopteran Pest ◽  
The Impact ◽  
Resistance To Viral Infection

There is an increasing appreciation of the importance of transgenerational effects on offspring fitness, including in relation to immune function and disease resistance. Here, we assess the impact of parental rearing density on offspring resistance to viral challenge in an insect species expressing density-dependent prophylaxis (DDP); i.e. the adaptive increase in resistance or tolerance to pathogen infection in response to crowding. We quantified survival rates in larvae of the cotton leafworm ( Spodoptera littoralis ) from either gregarious- or solitary-reared parents following challenge with the baculovirus S. littoralis nucleopolyhedrovirus. Larvae from both the parental and offspring generations exhibited DDP, with gregarious-reared larvae having higher survival rates post-challenge than solitary-reared larvae. Within each of these categories, however, survival following infection was lower in those larvae from gregarious-reared parents than those from solitary-reared, consistent with a transgenerational cost of DDP immune upregulation. This observation demonstrates that crowding influences lepidopteran disease resistance over multiple generations, with potential implications for the dynamics of host–pathogen interactions.

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