is a tachinid parasitoid of several significant heteropteran agricultural pests, including the southern green stink bug,
, and leaf-footed bug,
. To be used successfully as a biological control ...agent, the fly must selectively parasitize the target host species. Differences in the host preference of
were assessed by assembling the nuclear and mitochondrial genomes of 38 flies reared from field-collected
and
. High-quality de novo draft genomes of
were assembled using long-read sequencing. The assembly totaled 672 MB distributed among 561 contigs, having an N50 of 11.9 MB and a GC of 31.7%, with the longest contig at 28 MB. The genome was assessed for completeness using BUSCO in the Insecta dataset, resulting in a score of 99.4%, and 97.4% of the genes were single copy-loci. The mitochondrial genomes of the 38
flies were sequenced and compared to identify possible host-determined sibling species. The assembled circular genomes ranged from 15,345 bp to 16,390 bp and encode 22 tRNAs, two rRNAs, and 13 protein-coding genes (PCGs). There were no differences in the architecture of these genomes. Phylogenetic analyses using sequence information from 13 PCGs and the two rRNAs individually or as a combined dataset resolved the parasitoids into two distinct lineages:
that parasitized both
and
, and others that parasitized only
The southern green stink bug Nezara viridula (Linnaeus) is a polyphagous species that causes economic damages to many crops in Bulgaria. The aim of this study was to identify the parasitoid species ...that could suppress the populations of Nezara viridula. A lot of agricultural crops were inspected in the region of Plovdiv, Bulgaria, for the presence of egg parasitoids and imaginal parasitoids of the pest. Egg masses and adults of Nezara viridula were collected during the field surveys in 2019-2021 in Southern Bulgaria. The only parasitoid species emerging from adults of the green stink bug was Trichopoda pennipes (Tachinidae), which is reported for the first time in Bulgaria. The rate of parasitism at field conditions ranged from 2.83% to 35% in the different generations of the host. The egg parasitoids were from family Scelionidae - Trissolcus basalis (Wollaston), Eupelmidae - Anastatus bifasciatus (Geoffroy), and Encyrtidae - Ooencyrtus telenomicida (Vassiliev). It was found that at field conditions the rate of parasitism of the eggs in 2020 and 2021 was respectively 7.77% and 0.25% in May, 34.32% and 17.23% in June, 72.3% and 80.51% in July, and in August - reaching 100% and 89.79%.
The invasive brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), has been an important agricultural pest in the Mid-Atlantic United States since its introduction in 1996. ...Biological control by native species may play an important role in suppressing H. halys populations and reduce reliance on chemical control. We collected H. halys adults in agricultural areas of five Pennsylvania counties over two years to examine the extent and characteristics of adult stink bug parasitism by Trichopoda pennipes (Diptera: Tachinidae), a native parasitoid of hemipterans. The overall parasitism rate (in terms of T. pennipes egg deposition) was 2.38 percent. Rates differed among counties and seasons, but not between years. Instances of supernumerary oviposition were evident, and eggs were more commonly found on the ventral side of the thorax, although no differences in egg deposition were found between males and female hosts. T. pennipes has begun to target H. halys adults in Pennsylvania and has the potential to play a role in regulating this pest. Adult parasitism of H. halys by T. pennipes should continue to be monitored, and landscape management and ecological pest management practices that conserve T. pennipes populations should be supported in agricultural areas where H. halys is found.
Specimens of the feather-legged fly,
Trichopoda pennipes
(Fabricius) (Diptera: Tachinidae), which parasitize adults of the southern green stink bug
Nezara viridula
(L.) (Hemiptera: Pentatomidae), ...have been detected in Giza, Egypt. This is the first record of this Nearctic species with its genus (
Trichopoda
) and its tribe (Gymnosomatini) in Egypt.
T. pennipes
is known as an endoparasitoid of many true bug hosts, the pests of various crops, and it could have a potentiality to control these pests in addition to
N. viridula
, which is known to be its principal host. Taxonomy and diagnosis of the detected parasitoid species in addition to a checklist of the subfamily Phasiinae in Egypt are provided. Colored photographs of the parasitoid larval and adult stages and parasitized host are provided as well.
A two-year study evaluated the effect of a flowering border of buckwheat Fagopyrum esculentum Moench on rates of egg parasitism, egg predation and adult parasitism on two squash bug species, Anasa ...tristis (DeGeer) and Anasa armigera Say, by comparing rates in squash fields with and without a flowering border. Furthermore, we evaluated whether there was an edge effect by comparing parasitism and predation rates in plots located in the corner of a squash field with plots located in the center of a squash field for fields with and without a flowering border. The egg parasitism rates were not affected by either treatment (flowering border or control) or plot location (edge or center). Anasa armigera egg masses only accounted for 4.3% of the total egg masses collected. The egg parasitism rates increased gradually throughout the season, peaking in the last week of August in 2017 at 45% for A. tristis egg masses. The most common egg parasitoid recovered was Gryon pennsylvanicum (Ashmead) followed by Ooencyrtus anasae (Ashmead). Adult parasitism was not affected by treatment, but A. tristis adult parasitism rates were higher in plots located on the edge of squash fields compared with plots located in the center of squash fields in 2016. Since adult parasitoid, Trichopoda pennipes (Fabricius) flies were observed visiting buckwheat flowers, future studies could explore the possibility that the flowering buckwheat may have a more impact on adult parasitism if there was a greater distance between fields with and without a flowering border.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Trichopoda pennipes (F.) is a parasitoid species introduced in various countries as a biological control agent against the southern green stink bug Nezara viridula (L.). Several studies were ...performed to investigate the interactions between this parasitoid and the host, but they were focused above all on the adults. Our research was focused on the effects of exposure and parasitization by T. pennipes on the five-instar nymphs of N. viridula. We observed that the exposure to the parasitoid had effects on the development time of the five-instar nymphs and on the lifespan of the nymphs and the adults that emerged from them.
Adult parasitoids of pest insects rely on floral resources for survival and reproduction, but can be food-deprived in intensively managed agricultural systems lacking these resources. Stink bugs are ...serious pests for crops in southwest Georgia. Provisioning nectar-producing plants for parasitoids of stink bugs potentially can enhance biocontrol of these pests. Knowledge of spatial and temporal availability and distribution of stink bugs in host plants is necessary for appropriate timing and placement of flowering plants in agroecosystems. Stink bugs move between closely associated host plants throughout the growing season in response to deteriorating suitability of their host plants. In peanut-cotton farmscapes, stink bugs develop in peanut, and subsequently the adults disperse into adjacent cotton. Parasitism of
(L.) adults by
(F.) at the peanut-cotton interface was significantly higher in cotton with a strip of milkweed or buckwheat between the two crops than in cotton alone. Milkweed and buckwheat also provided nectar to a wide range of insect pollinators. Monarch butterflies fed on milkweed. When placed between peanut and cotton, a strip of soybean was an effective trap crop for cotton, reducing economic damage. Incorporation of buckwheat near soybean enhanced parasitism of
(Say) eggs by
Ashmead in cotton. In conclusion, nectar provision enhances biocontrol of stink bugs, acts together with other management tactics for stink bug control, and aids in conservation of natural enemies, insect pollinators, and the monarch butterfly.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The species composition and abundance of stink bugs (Heteroptera: Pentatomidae) in corn, Zea mays L., was determined in this on-farm study in Georgia. Seven species of phytophagous stink bugs were ...found on corn with the predominant species being Nezara viridula (L.) and Euschistus servus (Say). All developmental stages of these two pests were found, indicating they were developing on the corn crop. The remaining five species, Oebalus pugnax pugnax (F.), Euschistus quadrator (Rolston), Euschistus tristigmus (Say), Euschistus ictericus (L.), and Acrosternum hilare (Say), were found in relatively low numbers. Adult N. viridula were parasitized by the tachinid parasitoid Trichopoda pennipes (F.). There was a pronounced edge effect in distribution of stink bugs in corn. Population dynamics of N. viridula and E. servus were different on early and late-planted corn. Oviposition by females of both stink bug species occurred in mid-to-late-May and again mid-to-late-June in corn, regardless of planting date. In early planted fields, if stink bug females oviposited on corn in mid-July, the resulting nymphs did not survive to the adult stage in corn because ears were close to physiological maturity and leaves were senescing. Density of stink bug adults in early planted corn was relatively low throughout the growing season. In late-planted corn, females of both stink bug species consistently laid eggs in mid-to-late-July on corn with developing ears. This habitat favored continued nymph development, and the resulting adult population reached high levels. These results indicate that corn management practices play a key role in the ecology of stink bugs in corn agroecosystems and provide information for designing management strategies to suppress stink bugs in farmscapes with corn.
In peanut—cotton farmscapes in Georgia, the stink bugs Nezara viridula (L.) and Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and the leaffooted bug, Leptoglossus phyllopus (L.) (Hemiptera: ...Coreidae), disperse at crop-to-crop interfaces to feed on bolls in cotton. The main objective of this study was to determine whether insecticide-free tropical milkweed (Asclepias curassavica L.), a nectar-producing plant, can increase parasitism of these bugs by Trichopoda pennipes (F.) (Diptera: Tachinidae) and provide nectar to monarch butterflies and insect pollinators in these farmscapes. Peanut– cotton plots with and without flowering milkweed plants were established in 2009 and 2010. Adult T. pennipes, monarch butterflies, honey bees, and native insect pollinators readily fed on floral nectar of milkweed. Monarch larvae feeding on milkweed vegetation successfully developed into pupae. In 2009, N. viridula was the primary host of T. pennipes in cotton, and parasitism of this pest by the parasitoid was significantly higher in milkweed cotton (61.6%) than in control cotton (13.3%). In 2010, parasitism of N. viridula, C. hilaris, and L. phyllopus by T. pennipes was significantly higher in milkweed cotton (24.0%) than in control cotton (1.1%). For both years of the study, these treatment differences were not owing to a response by the parasitoid to differences in host density, because density of hosts was not significantly different between treatments. In conclusion, incorporation of milkweed in peanut— cotton plots increased stink bug parasitism in cotton and provided nectar to insect pollinators and monarch butterflies.
Susceptibility of the southern green stink bug, Nezara viridula (L.) (Heteroptera: Pentatomidae), and its endoparasitoid Trichopoda pennipes (F.) (Diptera: Tachinidae) to acetamiprid, cyfluthrin, ...dicrotophos, indoxacarb, oxamyl, and thiamethoxam was compared in residual and oral toxicity tests. In the residual toxicity test, cyfluthrin, dicrotophos, and oxamyl were highly toxic to N. viridula. Thiamethoxam was moderately toxic to these insects. Each of the four insecticides was highly toxic to T. pennipes after prolonged tarsal contact with dried residues of these chemicals. In the oral toxicity test, where N. viridula fed on food covered with insecticide residues, none of the insecticides were toxic to adults of this stink bug, but acetamiprid, dicrotophos, and thiamethoxam were moderately toxic to the nymphs. In the oral toxicity test, where N. viridula fed on a gel-food containing insecticides, cyfluthrin, dicrotophos, oxamyl, and thiamethoxam were highly toxic to this stink bug. In an oral toxicity test using contaminated sugar water, all of the insecticides were highly toxic to T. pennipes. Because insecticides were as toxic, or more toxic, to T. pennipes than to N. viridula, it is extremely important to conserve this parasitoid by applying these insecticides for control of southern green stink bugs only when the pest reaches economic threshold.
PDF
