Plodia interpunctella (Lepidoptera: Pyraloidea) is a notorious pest of stored grain globally. The dried fruits (Ziziphus jujuba, Malus pumila, and Fragaria ananassa) can strongly attract P. interpunctella. However, specific volatile compounds responsible for such effects have not been identified. Volatiles were analyzed by using headspace solid-phase microextraction (HS-SPME) and chromatography-mass spectrometry (GCMS) techniques. Five aldehyde compounds were selected for electroantennogram (EAG), single sensillum recording (SSR), and behavioral response assays. The three chemicals that elicited the strongest EAG responses to mated females at 100 μg/μL include hexanal (1.13 mV), heptanal (0.92 mV), and octanal (0.73 mV). In SSR experiments, the basiconic sensilla of the antennae responded to these aldehyde compounds. The results of behavioral responses showed that all aldehydes exhibited dose-dependent responses, with hexanal having the highest attractant rate of 74.56%. These compounds have the potential to be used for monitoring P. interpunctella and its integrated management program.

The sophisticated olfactory system of insects is plays a critical role in detecting chemical signals and guiding insect behaviors, such as selecting mates, finding hosts, evading predators, and discovering oviposition sites. Therefore, exploring and clarifying the molecular processes of this system is crucial for developing new insecticides or efficient pest control methods. Plodia interpunctella (Hübner) is a disruptive insect pest damaging the stored grains over the world. However, the olfactory processes of P. interpunctella remain unclear. Herein, we employed a transcriptome analysis to identify olfactory and differentially expressed genes to characterize their expression patterns in different developmental stages and antennal tissue. Subsequently, a total of 172 potential olfactory-related genes included 42 odorant-binding proteins, 12 chemosensory proteins, 51 odorant receptors, 13 gustatory receptors, three sensory neuron membrane proteins, and 51 ionotropic receptors. Furthermore, phylogenetic analysis and BLASTx best-hit analyses showed that these olfactory genes were closely linked with those identified in other lepidopterans. Transcriptome analysis revealed 49 differentially expressed olfactory-related genes, and a semiquantitative reverse transcription polymerase chain reaction showed that 11 olfactory genes were particularly expressed in the legs and wings of female P. interpunctella. Meanwhile, PintOBP29 was notably expressed in female antennae and legs. Genes with high expression levels in the abdomen showed high expression in the legs, but low expression in the antennae. Our findings provide the candidate genetic factors for analysis of the olfactory processes in P. interpunctella.

Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) originating from South America is one of the important insect pests that damages storage products and is found on every continent. There is a new interest in using enthomopathogens for microbial control of P. interpunctella as well as other stored product pests. Coccidia as a group of protistan entomopathogens are host specific and their pathogenic effects on the hosts are more pronounced. Although this pathogenic effect results in increased host mortality or higher susceptibility to insecticides, the suppressive potential of coccidia in natural populations has not been adequately studied. In this study, characterization, distribution and occurrence of a coccidian entomopathogen was aim to show its natural suppressing potential in P. interpunctella populations.
During the three years (from 2019 to 2021), a total of 3.432 P. interpunctella samples (2.047 dead and 413 living larvae, 932 adults and 40 pupae) were collected from fourteen populations. After macroscopic examination, suspected samples were dissected in Ringer\'s solution and then prepared wet smears including host fat body were examined for presence of coccidian pathogens under a light microscope at a magnification of 400-1000X. The oocysts of the coccidian were measured and photographed using a microscope with a digital camera and soft imaging system.
The pathogen was observed in the fat bodies of the larvae, pupae and adults. Oocysts measured as 29.52±3.32 (25.27- 35.08) μm in diameter and they include 8 sporocysts. Sporocysts measured as 9.11±0.61 (8.90-9.85) μm. Forty-five of 3.432 P. interpunctella larvae, pupae and adults were found to be infected. Coccidian infections have also reached to the levels that can be considered high in some populations, as significant as 29.2%. The infection was observed in the three (21.4%) of the examined fourteen populations.
The coccidian entomopathogen presented in this study is the first Adeleid coccidian record from P. interpunctella populations in Türkiye. The detection of Adelina mesnili Perez (Coccidia: Adeleidae) in at least three populations and the infection rate reaching 29.2 percent, confirms that this pathogen has a considerable effect P. interpunctella populations that cannot be underestimated. Our results confirm that the coccidian pathogen is very effective in the larval stage.
Güney Amerika kökenli Plodia interpunctella (Hübner) (Lepidoptera Pyralidae) her kıtada bulunan ve depolama ürünlerine zarar veren önemli zararlılardan biridir. P. interpunctella ve diğer depolanmış ürün zararlılarının mikrobiyal kontrolü için entomopatojenlerin kullanımına yönelik bir ilgi vardır. Bir protistan entomopatojen grubu olarak Coccidia, konakçıya özgü olup, konaklar üzerindeki patojenik etkileri daha belirgindir. Bu patojenik etki, artan konakçı ölümü veya insektisitlere karşı daha yüksek duyarlılık ile sonuçlanmasına rağmen, doğal popülasyonlarda coccidianların baskılayıcı potansiyeli yeterince araştırılmamıştır. Bu çalışmada, bir coccidian entomopatojenin karakterizasyonun yapılması, dağılımı ve enfeksiyon oranlarının belirlenerek P. interpunctella popülasyonlarındaki doğal baskılama potansiyelinin ortaya konulması amaçlanmıştır.
Üç yıl boyunca (2019-2021), on dört popülasyondan toplam 3,432 P. interpunctella örneği (2,047 ölü, 413 canlı larva, 932 ergin ve 40 pupa) toplanmıştır. Makroskopik incelemeden sonra, şüpheli numuneler Ringer solüsyonunda disekte edilmiş ve daha sonra konak yağ dokusunu içeren preperatlar hazırlanarak Coccidian patojenlerin varlığı açısından ışık mikroskobunda 400-1000X büyütmede incelenmiştir.
Patojen larva, pupa ve erginlerin yağ dokusunda gözlenmiştir. 29,52±3,32 (25,27-35,08) μm çapında ölçülen ookistler, 8 sporokist içermektedir. Sporokistler 9,11±0,61 (8,90-9,85) μm olarak ölçülmüştür. İncelenen 3,432 P. interpunctella larva, pupa ve ergininin 45 tanesinin enfekte olduğu tespit edilmiştir. Coccidian enfeksiyonlarının bazı popülasyonlarda %29,2 gibi önemli sayılabilecek seviyelere ulaştığı tespit edilmiştir. Enfeksiyon, incelenen on dört popülasyonun üçünde (%21,4) gözlenmiştir.
Bu çalışmada sunulan coccidian entomopatojen, Türkiye’deki P. interpunctella popülasyonlarından elde edilen ilk Adeleid Coccidian kaydıdır. Adelina mesnili Perez\'in (Coccidia: Adeleidae) en az üç popülasyonda saptanması ve enfeksiyon oranının %29,2’ye ulaşması, bu patojenin P. interpunctella popülasyonlarında küçümsenemeyecek kadar önemli bir etkiye sahip olduğunu doğrulamaktadır.

The Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae), a globally distributed storage pest, relies on odors that are emitted from stored foods to select a suitable substrate for oviposition. However, the molecular mechanism underlying the chemical communication between P. interpunctella and its host remains elusive. In this study, 130 chemosensory genes were identified from the transcriptomes of 7 P. interpunctella tissues, and the quantitative expression levels of all 56 P. interpunctella odorant receptor genes (PintORs) were validated using real-time quantitative polymerase chain reaction. The functional characteristics of 5 PintORs with female antennae-biased expression were investigated using 2-electrode voltage clamp recordings in Xenopus laevis oocytes. PintOR23 was found to be specifically tuned to acetophenone. Acetophenone could elicit a significant electrophysiological response and only attracted mated females when compared with males and virgin females. In addition, molecular docking predicted that the hydrogen bonding sites, TRP-335 and ALA-167, might play key roles in the binding of PintOR23 to acetophenone. Our study provides valuable insights into the olfactory mechanism of oviposition substrate detection and localization in P. interpunctella and points toward the possibility of developing eco-friendly odorant agents to control pests of stored products.

The sterile insect technique (SIT) is considered an environmentally friendly, autocidal control tactic to manage insect pests. This work dealt with the improvement of quality management of the Indian meal moth Plodia interpunctella (Hübner) for enhanced efficacy of the SIT. The results indicated that egg hatching of irradiated mature eggs of P. interpunctella was higher than that of younger eggs, indicating that mature eggs were significantly more tolerant than younger eggs. Moreover, our data revealed that a dose of 500 Gy completely prevented pupal formation in irradiated young and mature larvae. Crosses between irradiated and non-irradiated adults resulted in considerable variations in fecundity. The mating competitiveness index (CI) value was higher for a ratio of 5:1:1 (sterile male, fertile male, and fertile female, respectively) as compared with the ratio 1:1:1 for the irradiated individuals of all life stages. Low temperature (5 °C) maintenance of irradiated pupae significantly affected adult emergence. Using cylinders to assess flight ability, we found that the flight performance of adults that were developed from cold treated irradiated pupae was influenced by cylinder diameter, cylinder height and the number of hours the insects were in the cylinders. The percentage of DNA damage of the reproductive organs of adults developed from cold treated pupae that were irradiated with 100 and 150 Gy varied significantly. The results of this study should be used to implement pilot-scale field tests aiming at a sterile- to-fertile male ratio of 5 to 1.

Understanding the development and reproduction of insects surviving controlled atmosphere treatment may help in developing sound pest management strategies. The developmental duration, survival percentage, and oviposition of Plodia interpunctella and its F1 generation were determined after the fifth instar larvae (the last-stage larvae) were exposed to 98% N2 for different exposure times. The survival percentage of the last-stage larvae treated with 98% N2 for 6, 4, 1.5, and 0 day was 70, 80, 91, and 100%, respectively when measured 24 h after treatment. The survival percentage of the last-stage larvae that developed to pupae was 37, 55, 73, and 96%, corresponding to the different exposure times. The developmental time needed to pass from pupa to adult emergence of specimens treated as the last-stage larvae were 8, 7, 6, and 6 days corresponding respectively to high N2 treatment after 6, 4, 1.5, and 0 day of exposure. The mean number of eggs laid by the subsequent females developed from the treated last-stage larvae was 35, 66, 81, and 123, respectively. The oviposition inhibition ratio of the F1 generation decreased by more than 33% compared with that of the parental generation. When the last-stage larvae were exposed to 98% N2 for longer than 4 days, the immature developmental time of surviving individuals in the F1 generation was delayed more than 6 days due to slower egg hatching and longer development of the first and second instar larvae stages. The population trend index of the F1 generation was lower when raised from the treated last-stage larvae than those from untreated controls.

ATP binding cassette (ABC) proteins are involved in transport of substrates across membranes including eye pigments. Mutations of ABC transporter white, brown and scarlet genes of Drosophila and other insects result in visible eye color phenotypes. White locus was identified in a genome assembly of Plodia interpunctella and was found to extend for 16,670 bp comprising 13 exons. We report here recovery of heritable mutants in white in the Indian meal moth, P. interpunctella, using CRISPR/Cas9-mediated mutagenesis. A white eye strain of P. interpunctella c.737delC (Piw-/-) was previously isolated in 1986. Guide RNA (sgRNA) was designed for exon 1 (sgRNA242). Microinjection of Cas9/sgRNA242 complex into Plodia wild type eggs (≤20 min post oviposition) produced 156 viable larvae of which 81 eclosed as adults. Forty-five (56 %) adults displayed wild type phenotype, while 26 females (32 %) and 10 males (12 %) showed full or partial white eye phenotype. The 26 white eye females were mated with Piw-/- males and 21 matings resulted in F1 white eye progeny. Thirteen of the Piw-242 lines were established and sequencing showed indels at the CRISPR/Cas9 242AM site. Based on RT-PCR analysis, most white mutations resulted in suppressed levels of transcript. These results demonstrate the utility of CRISPR/Cas9 gene editing in Plodia which suggests this technology can be used to characterize the role of various genetic elements including those that encode novel targets or confer insecticide resistance mechanisms.

A steady supply of hosts at the susceptible stage for parasitism is a major component of mass rearing parasitoids for biological control programs. Here we describe the effects of storing 5th instar Plodia interpunctella larvae in dormancy on subsequent host development in the context of host colony maintenance and effects of the duration of host dormancy on the development of Habrobracon hebetor parasitoids reared from dormant hosts. We induced dormancy with a combination of short daylength (12L:12D) and lower temperature (15°C), conditions known to induce diapause in this species, and held 5th instar larvae of P. interpunctella for a series of dormancy durations ranging from 15 to 105 days. Extended storage of dormant 5th instar larvae had no significant impacts on survival, development, or reproductive potential of P. interpunctella, reinforcing that dormant hosts have a substantial shelf life. This ability to store hosts in dormancy for more than 3 months at a time without strong negative consequences reinforces the promise of using dormancy to maintain host colonies. The proportion of hosts parasitized by H. hebetor did not vary significantly between non-dormant host larvae and dormant host larvae stored for periods as long as 105 days. Concordant with a prior study, H. hebetor adult progeny production from dormant host larvae was higher than the number of progeny produced on non-dormant host larvae. There were no differences in size, sex ratio, or reproductive output of parasitoids reared on dormant hosts compared to non-dormant hosts stored for up to 105 days. Larval development times of H. hebetor were however longer when reared on dormant hosts compared to non-dormant hosts. Our results agree with other studies showing using dormant hosts can improve parasitoid mass rearing, and we show benefits for parasitoid rearing even after 3 months of host dormancy.

The Indian meal moth Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is a notorious stored-grain pest that can be found in most parts of China. The corpses, excretions, and other secretions of P. interpunctella larvae cause serious grain pollution, seriously affecting the nutritional and economic value of stored grain in China. To elucidate the potential distribution of P. interpunctella in China, we used the CLIMEX 4.0 model to project the potential distribution of the pest using historical climate data (1960-1990) and estimated future climate data (2030, 2050, and 2070). Under the historical climate situation, P. interpunctella was distributed in most areas of China, and its highly favorable habitats account for 48.14% of its total potential distribution. Because of temperature change in the future climate, suitable habitats will increase in the eastern part of Qinghai and will decrease in the mid-eastern, northeastern, and southeastern parts of China. Under these scenarios, the area of this pest\'s highly favorable habitat will be reduced by 1.24 million km2, and its proportion will decrease to about 28.48%. These predicted outcomes will help to distinguish the impact of climate change on the potential distribution of P. interpunctella, thereby providing important information to design early forecasting and strategies to prevent pest harm to stored grain.

The Indian meal moth (Plodia interpunctella, Lepidoptera) is a common insect species and well-known, widespread kitchen pest. This paper reports the results of their interaction with silicone baking moulds and the evidence for synthetic material decomposition. The obtained fibres exhibited a high level of purification and were characterized by Raman spectroscopy. The reported interaction should be further studied from the biological perspective, as it can be crucial for the remediation of silicones or other synthetic polymers in the environment.