scholarly journals Morphological variation ofAphidius erviHaliday (Hymenoptera: Braconidae) associated with different aphid hosts

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3559 ◽  
Author(s):  
Cinthya M. Villegas ◽  
Vladimir Žikić ◽  
Saša S. Stanković ◽  
Sebastián A. Ortiz-Martínez ◽  
Ainara Peñalver-Cruz ◽  
...  

BackgroundParasitoids are frequently used in biological control due to the fact that they are considered host specific and highly efficient at attacking their hosts. As they spend a significant part of their life cycle within their hosts, feeding habits and life history of their host can promote specialization via host-race formation (sequential radiation). The specialized host races from different hosts can vary morphologically, behaviorally and genetically. However, these variations are sometimes inconspicuous and require more powerful tools in order to detect variation such as geometric morphometrics analysis.MethodsWe examinedAphidius ervi, an important introduced biological control agent in Chile associated with a great number of aphid species, which are exploiting different plant hosts and habitats. Several combinations (biotypes) of parasitoids with various aphid/host plant combinations were analyzed in order to obtain measures of forewing shape and size. To show the differences among defined biotypes, we chose 13 specific landmarks on each individual parasitoid wing. The analysis of allometric variation calculated in wing shape and size over centroid size (CS), revealed the allometric changes among biotypes collected from different hosts. To show all differences in shape of forewings, we made seven biotype pairs using an outline-based geometric morphometrics comparison.ResultsThe biotypeA. pis_pea(Acyrthosiphon pisumon pea) was the extreme wing size in this study compared to the other analyzed biotypes. Aphid hosts have a significant influence in the morphological differentiation of the parasitoid forewing, splitting biotypes in two groups. The first group consisted of biotypes connected withAcyrthosiphon pisumon legumes, while the second group is composed of biotypes connected with aphids attacking cereals, with the exception of theR. pad_wheat(Rhopalosiphum padion wheat) biotype. There was no significant effect of plant species on parasitoid wing size and shape.DiscussionAlthough previous studies have suggested that the genotype of parasitoids is of greater significance for the morphological variations of size and shape of wings, this study indicates that the aphid host on whichA. ervidevelops is the main factor to alter the structure of parasitoid forewings. Bigger aphid hosts implied longer and broader forewings ofA. ervi.

2021 ◽  
Author(s):  
Hao-Sen Li ◽  
Yu-Hao Huang ◽  
Mei-Lan Chen ◽  
Zhan Ren ◽  
Bo-Yuan Qiu ◽  
...  

Abstract Background The ladybird beetle Cryptolaemus montrouzieri Mulsant (Coleoptera, Coccinellidae) is used worldwide as a biological control agent. It is a predator of various mealybug pests, but it also feeds on alternative prey and can be reared on artificial diets. Relatively little is known about the underlying genetic adaptations of its feeding habits. Results We report the first high-quality genome sequence for C. montrouzieri. We found that the gene families encoding chemosensors and digestive and detoxifying enzymes among others were significantly expanded or contracted in this ladybird in comparison to other beetles. Diet-specific larval transcriptome profiling demonstrated that differentially expressed genes on unnatural diet as compared to natural prey were enriched in pathways of nutrient metabolism, indicating that the lower performance on the tested diets was caused by nutritional deficiencies. Remarkably, the C. montrouzieri genome also showed a significant expansion in an immune effector gene family. Some of the immune effector genes were dramatically downregulated when larvae were fed unnatural diets. Conclusion We suggest that the evolution of genes related to chemosensing, digestion, and detoxification but also immunity might be associated with diet adaptation of an insect predator. These findings help explain why this predatory ladybird has become a successful biological control agent and will enable the optimization of its mass rearing and use in biological control programs.


ZooKeys ◽  
2020 ◽  
Vol 930 ◽  
pp. 75-88
Author(s):  
Vukica Vujić ◽  
Luka Lučić ◽  
Sofija Pavković-Lučić ◽  
Bojan Ilić ◽  
Zvezdana Jovanović ◽  
...  

Until now, morphological trait variation has been investigated in several millipede species using geometric morphometrics. The present study is the first attempt to explore sexual shape and size dimorphism (SShD and SSD) of morphological structures in Polydesmida. We here analyse antennal, head, and leg SShD and SSD in Brachydesmus troglobius Daday, 1889. Our results show that SSD exists in all of the analysed structures, while SShD is present only in the legs. In comparison with females, males possess longer and wider legs, as well as longer antennae and a shorter head. Contrary to previous findings in some Julida, in B. troglobiusSSD of the antennae and legs varies more than SShD in these morphological structures.


2012 ◽  
Vol 65 ◽  
pp. 290-290
Author(s):  
S. Read ◽  
B.G. Howlett ◽  
B.J. Donovan ◽  
W.R. Nelson ◽  
R.F. Van_Toor ◽  
...  

Honeybee colonies infested with the varroa mite (Varroa destructor) usually collapse unless they have been treated with acaracides Resistance to the most commonly used acaracides is increasing and no biological control options are yet available Chelifers (pseudoscorpions) are generalist predators and may have potential as a biological control agent This poster describes an attempt to establish breeding populations of native chelifers which have been shown to actively feed on varroa with the ultimate aim of testing their ability as a biological control of varroa Two species of chelifers (Nesochernes gracilis and Heterochernes novaezealandiae) collected from honeybee hives and in leaf litter near apiaries at Katikati (Bay of Plenty) are being maintained in the laboratory They are surviving on a variety of different food sources such as Drosophila sp larvae (fruit fly) aphids (Acyrthosiphon pisum) and moth larvae (Helicoverpa armigera Spodoptera litura and Plodia interpunctella) With little known about raising these chelifers in captivity their diet preferences and feeding periods are being obtained as a first step to obtaining the basic information necessary for potential commercial propagation of chelifers for varroa control in honeybee hives


2004 ◽  
Vol 57 ◽  
pp. 214-220 ◽  
Author(s):  
X.Z. He ◽  
Q. Wang ◽  
D.A.J. Teulon

Aphidius ervi Haliday is an important parasitoid of several aphid species and information is needed for the development of massrearing techniques and better understanding of biological control ecology The emergence sexual maturation and oviposition of A ervi on pea aphid Acyrthosiphon pisum (Harris) was studied in the laboratory at 201deg;C and 6070 RH with 168 h lightdark About 95 of parasitoids emerged during the photophase Females needed a significantly longer time than males to complete their life cycle Newly emerged males were able to perform their courtship display but failed to mate until they were 4 h old; newly emerged females were able to respond to males courtship display and mate Females attacked aphids in both light and dark conditions The number of eggs laid and parasitism (number of aphids parasitised) per oviposition bout (2 h oviposition period) were significantly greater in the photophase than in the scotophase


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242159
Author(s):  
Ailsa H. C. McLean ◽  
Benjamin J. Parker

Evolutionary interactions between parasitoid wasps and insect hosts have been well studied at the organismal level, but little is known about the molecular mechanisms that insects use to resist wasp parasitism. Here we study the interaction between a braconid wasp (Aphidius ervi) and its pea aphid host (Acyrthosiphon pisum). We first identify variation in resistance to wasp parasitism that can be attributed to aphid genotype. We then use transcriptome sequencing to identify genes in the aphid genome that are differentially expressed at an early stage of parasitism, and we compare these patterns in highly resistant and susceptible aphid host lines. We find that resistant genotypes are upregulating genes involved in carbohydrate metabolism and several key innate immune system genes in response to parasitism, but that this response seems to be weaker in susceptible aphid genotypes. Together, our results provide a first look into the complex molecular mechanisms that underlie aphid resistance to wasp parasitism and contribute to a broader understanding of how resistance mechanisms evolve in natural populations.


Author(s):  
K. B. Ferguson ◽  
S. Visser ◽  
M. Dalíková ◽  
I. Provazníková ◽  
A. Urbaneja ◽  
...  

AbstractNesidiocoris tenuis (Reuter) is an efficient predatory biological control agent used throughout the Mediterranean Basin in tomato crops but regarded as a pest in northern European countries. Belonging to the family Miridae, it is an economically important insect yet very little is known in terms of genetic information – no published genome, population studies, or RNA transcripts. It is a relatively small and long-lived diploid insect, characteristics that complicate genome sequencing. Here, we circumvent these issues by using a linked-read sequencing strategy on a single female N. tenuis. From this, we assembled the 355 Mbp genome and delivered an ab initio, homology-based, and evidence-based annotation. Along the way, the bacterial “contamination” was removed from the assembly, which also revealed potential symbionts. Additionally, bacterial lateral gene transfer (LGT) candidates were detected in the N. tenuis genome. The complete gene set is composed of 24,688 genes; the associated proteins were compared to other hemipterans (Cimex lectularis, Halyomorpha halys, and Acyrthosiphon pisum), resulting in an initial assessment of unique and shared protein clusters. We visualised the genome using various cytogenetic techniques, such as karyotyping, CGH and GISH, indicating a karyotype of 2n=32 with a male-heterogametic XX/XY system. Additional analyses include the localization of 18S rDNA and unique satellite probes via FISH techniques. Finally, population genomics via pooled sequencing further showed the utility of this genome. This is one of the first mirid genomes to be released and the first of a mirid biological control agent, representing a step forward in integrating genome sequencing strategies with biological control research.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anna Janczyk ◽  
Adam Tofilski

AbstractHoney bee (Apis mellifera) wing measurements are often used to discriminate lineages and subspecies. The precision and repeatability of the measurements depends on various factors, including seasonal variation, and differences between left and right wings. The seasonal variation of the cubital index, which is the proportion of two vein lengths, has been investigated, but subspecies can be identified through geometric morphometrics. This method allows both wing size and shape to be determined and analyzed separately. We studied changes in the wing size and shape in consecutive months between June and September as well as the differences between the left and right wings. We found that wing size differed significantly among colonies, months and body sides, but shape differed significantly only among colonies and months but not among body sides. There was also a complicated pattern of interactions between various factors. The seasonal differences in wing shape were much smaller than the differences among colonies and their influence on identification of honey bee lineages was relatively small.


2009 ◽  
Vol 78 (3) ◽  
pp. 129-140 ◽  
Author(s):  
Lj. Francuski ◽  
A. Vujić ◽  
A. Kovačević ◽  
J. Ludoški ◽  
V. Milankov

The present study investigates phenotypic differentiation patterns among four species of the Cheilosia variabilis group (Diptera, Syrphidae) using a landmark-based geometric morphometric approach. Herein, wing geometric morphometrics established species boundaries that confirm C. melanopa and C. redi stat. nov. as evolutionarily independent entities or separate species within the previously described C. melanopa species. Seventeen samples of C. lasiopa, C. variabilis, C. melanopa and C. redi from 11 localities on the Balkan Peninsula were analysed. Based on wing shape and size, both species boundaries and intraspecific divergent units were delineated indicating the possible presence of evolutionarily independent units within the analysed taxa. Significant differences in wing size were obtained among the analysed species and canonical variate analysis showed that wing shape was sufficiently different to allow the correct classification of 99.7% and 100% individuals of males and females, respectively. Considerable wing size variation was detected among males and females of conspecific populations of C. melanopa and males of C. variabilis. Contrary to partial discrimination based on the male wing shape among conspecific populations of C. redi and C. variabilis, clear separation of conspecific populations of C. melanopa (for both sexes) and females of C. redi and C. variabilis was observed. The UPGMA cluster analysis based on squared Mahalanobis distances revealed a close similarity between C. melanopa and C. redi, whereas C. lasiopa was the most divergent species. Results presented in this study utilize wing shape and size as new taxonomic characters in delimitating the closely related species and populations of the Cheilosia variabilis group.


Zootaxa ◽  
2020 ◽  
Vol 4729 (3) ◽  
pp. 347-358
Author(s):  
TODD M. GILLIGAN ◽  
DONALD J. WRIGHT ◽  
RICHARD L. BROWN ◽  
BENNO A. AUGUSTINUS ◽  
URS SCHAFFNER

The ragweed borer, Epiblema strenuana (Walker, 1863), has a long history of use as a biological control agent against important weed pests in the family Asteraceae. Recently, E. strenuana has been reported feeding on the invasive perennials Ambrosia confertiflora and A. tenuifolia in Israel. The geographic location of Israel has raised concern over the possibility that the moth may spread to areas such as Ethiopia where the oil-seed crop Guizotia abyssinica is cultivated, as this is a potential host for E. strenuana. However, the taxonomic status of E. strenuana and a current synonym, E. minutana (Kearfott, 1905) is unclear. These taxa have been treated as separate species in the past, and they potentially have different feeding habits and damage different parts of the plant. We analyzed DNA data and adult morphology and determined that E. minutana, stat. rev., is a valid species which we raise from synonymy with E. strenuana. Wing coloration, the shape of the female sterigma, and COI DNA barcodes are consistently different between the two species. We also determined that the species previously identified as E. strenuana in Israel is actually E. minutana. While detailed host range tests have been conducted on the E. strenuana populations released in Australia and China, the host range of E. minutana remains to be clarified. We discuss the history of biological control using E. strenuana and the implications for finding E. minutana in Israel. We also provide species redescriptions for E. strenuana and E. minutana and illustrate diagnostic characters. 


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hao-Sen Li ◽  
Yu-Hao Huang ◽  
Mei-Lan Chen ◽  
Zhan Ren ◽  
Bo-Yuan Qiu ◽  
...  

Abstract Background The ladybird beetle Cryptolaemus montrouzieri Mulsant, 1853 (Coleoptera, Coccinellidae) is used worldwide as a biological control agent. It is a predator of various mealybug pests, but it also feeds on alternative prey and can be reared on artificial diets. Relatively little is known about the underlying genetic adaptations of its feeding habits. Results We report the first high-quality genome sequence for C. montrouzieri. We found that the gene families encoding chemosensors and digestive and detoxifying enzymes among others were significantly expanded or contracted in C. montrouzieri in comparison to published genomes of other beetles. Comparisons of diet-specific larval development, survival and transcriptome profiling demonstrated that differentially expressed genes on unnatural diets as compared to natural prey were enriched in pathways of nutrient metabolism, indicating that the lower performance on the tested diets was caused by nutritional deficiencies. Remarkably, the C. montrouzieri genome also showed a significant expansion in an immune effector gene family. Some of the immune effector genes were dramatically downregulated when larvae were fed unnatural diets. Conclusion We suggest that the evolution of genes related to chemosensing, digestion, and detoxification but also immunity might be associated with diet adaptation of an insect predator. These findings help explain why this predatory ladybird has become a successful biological control agent and will enable the optimization of its mass rearing and use in biological control programs.


Sign in / Sign up

Export Citation Format

Share Document