Moth Mating Research Articles

Plasticity in moth mating behavior and ejaculate proteomic diversity induced by male competition

In male competition, large and costly ejaculates are advantageous. Prior research on male accessory gland secretions in Plutella xylostella left open questions about how males modulate their mating behaviors and ejaculate composition allocation in response to varying levels of competition. The current study aimed to delve deeper into these unexplored facets. A totally of 928 ejaculate proteins were identified across males exposed to different competition conditions. Notably, males courting under non–, low-, and high-competition scenarios exhibited 867, 635, and 858 ejaculate proteins, respectively. Approximately 10% of these ejaculate proteins displayed variations that aligned with changes in competition intensity. Subsequent analyses focused on the proteins transferred to females, revealing that 44% of ejaculate proteins were transferred, with 37 proteins exhibiting differential expression. Functional analyses uncovered their crucial roles in sperm maturation, motility, and capacitation. Our findings reveal adaptive adjustments in ejaculate protein abundance and transmission in P. xylostella as a response to varying competition levels. Moreover, fluorescent sperm labeling indicated higher sperm transfer during low competition correlated with shorter sperm length. Furthermore, evidence suggests that males shorten their courtship duration and extend their mating duration when faced with competition. These results illustrate how competition drives ejaculate investment and behavioral plasticity, offering valuable insights for advancements in assisted reproductive technologies and pest management strategies.

Impact of Coupling Duration on Fecundity and Fertility of Muga Silkworm (Antheraea assamensis Helfer) During Grainage Operation

Quality seed production is considered the backbone of the sericulture industry. Eggs are the primary and fundamental component of Muga culture, so the production of quality eggs is imperative. For successful production of cocoon crops, an adequate quantity of good-quality eggs is essential. In the case of silk moth mating, the time varies from 5 to 8 hours, which is generally termed as the coupling period. The temporal aspects of mating in terms of duration may also impact the number of eggs laid, the pattern of egg laying, and their viability. The present investigation intends to find out whether the duration of the coupling period has any relation with the fecundity and fertility of silk moths. The study was conducted with the Muga Silkworm (Antheraea assamensis Helfer) in Baisakhi and Bhodia seed crops. The experiment reveals that total fecundity almost remains the same above 5 hours of coupling duration, but fertility is directly proportional to the coupling duration and reaches a maximum (85%) at 7-8 hours of coupling duration. It is also observed that coupling duration of more than 8 hours also affects the fecundity of Muga silk moths, but fertility remains the same as the control batch or the 7-8 hour batch.

CRISPR/Cas9-mediated knockout of scarlet gene produces eye color mutants in the soybean looper, Chrysodeixis includens.

The CRISPR/Cas9 technology has greatly progressed research on non-model organisms, demonstrating successful applications in genome editing for various insects. However, its utilization in the case of the soybean looper, Chrysodeixis includens, a notable pest affecting soybean crops, has not been explored due to constraints such as limited genomic information and the embryonic microinjection technique. This study presents successful outcomes in generating heritable knockout mutants for a pigment transporter gene, scarlet, in C. includens through CRISPR/Cas9-mediated mutagenesis. The scarlet locus identified in the genome assembly of C. includens consists of 14 exons, with a coding sequence extending for 1,986 bp. Two single guide RNAs (sgRNAs) were designed to target the first exon of scarlet. Microinjection of these two sgRNAs along with the Cas9 protein into fresh embryos resulted in the successful production of variable phenotypes, particularly mutant eyes. The observed mutation rate accounted for about 16%. Genotype analysis revealed diverse indel mutations at the target site, presumably originating from double-strand breaks followed by the nonhomologous end joining repair, leading to a premature stop codon due to frame shift. Single-pair mating of the mutant moths produced G1 offspring, and the establishment of a homozygous mutant strain occurred in G2. The mutant moths exhibited lightly greenish or yellowish compound eyes in both sexes, confirming the involvement of scarlet in pigmentation in C. includens. Notably, the CRISPR/Cas9-mediated genome editing technique serves as a visible phenotypic marker, demonstrating its proof-of-concept applicability in C. includens, as other pigment transporter genes have been utilized as visible markers to establish genetic control for various insects. These results provide the first successful case that the CRISPR/Cas9 method effectively induces mutations in C. includes, an economically important soybean insect pest.

Characterization of the pheromone receptors in Mythimna loreyi reveals the differentiation of sex pheromone recognition in Mythimna species.

Pheromone receptors (PRs) are key proteins in the molecular mechanism of pheromone recognition, and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating systems. Pheromone components of the agricultural pest Mythimna loreyi have turned into (Z)-9-tetradecen-1-yl acetate (Z9-14:OAc), (Z)-7-dodecen-1-yl acetate (Z7-12:OAc), and (Z)-11-hexadecen-1-yl acetate, while the composition differs from that of M. separata in the genus Mythimna. To understand the molecular mechanism of pheromone recognition, we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor (OR) genes. The expression levels of all putative ORs were analyzed using differentially expressed gene analysis. Six candidate PRs were quantified and functionally characterized in the Xenopus oocytes system. MlorPR6 and MlorPR3 were determined to be the receptors of major and minor components Z9-14:OAc and Z7-12:OAc. MlorPR1 and female antennae (FA)-biased MlorPR5 both possessed the ability to detect pheromones of sympatric species, including (Z,E)-9,12-tetradecadien-1-ol, (Z)-9-tetradecen-1-ol, and (Z)-9-tetradecenal. Based on the comparison of PR functions between M. loreyi and M. separata, we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species.

BIOLOGICAL CONTROL OF CODLING MOTH, CYDIA POMONELLA (L.) IN APPLE ORCHARDS OF BULGARIA USING GINKO® DISPENSERS

The codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), is a significant pest of pome fruit and walnut orchards worldwide and it is a particular problem in Bulgaria. Codling moth resistance to many insecticides has been recently detected in Bulgaria. Codling moth (CM) mating disruption with Ginko® dispensers was evaluated in four successive years from 2019 to 2022 as part of an anti-resistance strategy. In an isolated 3 ha apple orchard in the Plovdiv district of South-Central Bulgaria, close to the town of Perushtitsa, field tests were conducted for the control of the codling moth (CM), C. pomonella, via mating disruption (MD) using pheromone Ginko® dispensers. The pheromone dispensers were hung in the upper third of tree canopies with a density of 500 dispensers/ha before CM flight started. Dynamics of CM flights was monitored by pheromone traps installed in the trial plot and in a conventionally treated reference orchard. Two types of baits were used in the traps: PHEROCON® CM L2–codlemone lures and PHEROCON® CM DA COMBO-P + AA lures (Trécé Inc., USA) in the orchards for mating disruption. The PHEROCON® CM L2 lures were changed at 4-week intervals and PHEROCON® CM DA COMBO-P + AA lures at 8-week intervals. PHEROCON® VI Delta sticky traps baited with PHEROCON CM DA COMBO- P + AA lures and standard CM L2 caps were installed, for comparison, in a reference orchard located in the Plovdiv region. Fruit infestation was periodically assessed till the harvest time. In both years fruit damage remained lower till late July and increased slightly only in August. At harvest, fruit damage remained below 1%. It was obvious that mating disruption could be useful strategy for the control of codling moth in Bulgarian apple orchards, specifically when the plot is isolated from external sources of infestation and the population density of the pest is low.

Effect of X-ray irradiation on development, flight, and reproduction of Spodoptera litura

Spodoptera litura is an omnivorous pest that has spread globally. Because irradiation sterilization technology has a great potential for control of S. litura, the effect of 25–150 Gy doses of X-rays on pupal survival, flight and reproductive variables of adult moths were analyzed in this research. The X-ray irradiation with the dose of 25–150 Gy significantly affected the reproductive ability of females. Irradiating male pupae with 25–150 Gy doses of X-rays had no effect on mating, life span, or flight ability of adult moths, but significantly reduced survival and fecundity of their offspring, and the sterility rate of the F1 generation was 52.65%–99.9%. The results of logistic curve fitting showed that the sterility impact was 84% at the most appropriate irradiation dose (71.26 Gy). The sterility control was 91% in an indoor mating competition experiment when the release ratio of irradiated males (75 Gy) to nonirradiated males reached 12.6:1. The effects of X-ray irradiation doses on biological variables of S. litura and the most effective release ratio determined here provide a theoretical foundation for using radiation sterilization technology to control S. litura.

Dim Red Light During Scotophase Enhances Mating of a Moth Through Increased Male Antennal Sensitivity Against the Female Sex Pheromone.

Insects are behaviorally and physiologically affected by different light conditions, including photoperiod, light intensity, and spectrum. Light at night has important influences on nocturnal insects, including most moth species. Moth copulation and mating usually occur at night. Although a few studies examine changes in insect mating under artificial light at night, detailed influences of light, such as that of monochromatic light, on moth mating remain largely unknown. In this study, on the basis of long-term insects rearing experience, dim red light (spectrum range: 610–710nm, with a peak at 660nm; 2.0 Lux) during scotophase was hypothesized to enhance mating in the yellow peach moth, Conogethes punctiferalis. To test the hypothesis, the mating of moths under dim red, blue, and white lights during scotophase was observed. Under the dim red light, the enhancement of mating in C. punctiferalis was observed. In addition, the electroantennografic response of males against the female sex pheromone increased with red light treatment during scotophase. In an analysis of the differentially expressed genes in the antennae of males under red light and dark conditions, the expression levels of two odorant-binding protein (OBP) genes, CpunOBP2 and CpunPBP5, were up-regulated. Two genes were then expressed in Escherichia coli, and the recombinant proteins showed strong binding to female pheromone components in fluorescence-binding assays. Thus, the results of this study indicated that dim red light at night enhanced the mating of C. punctiferalis. One of the mechanisms for the enhancement was probably an increase in the antennal sensitivity of males to the female sex pheromone under red light that was caused by increases in the expression levels of pheromone-binding protein genes in male antennae.

Moth Mating: Modeling Female Pheromone Calling and Male Navigational Strategies to Optimize Reproductive Success

Male and female moths communicate in complex ways to search for and to select a mate. In a process termed calling, females emit small quantities of pheromones, generating plumes that spread in the environment. Males detect the plume through their antennae and navigate toward the female. The reproductive process is marked by female choice and male–male competition, since multiple males aim to reach the female but only the first can mate with her. This provides an opportunity for female selection on male traits such as chemosensitivity to pheromone molecules and mobility. We develop a mathematical framework to investigate the overall mating likelihood, the mean first arrival time, and the quality of the first male to reach the female for four experimentally observed female calling strategies unfolding over a typical one-week mating period. We present both analytical solutions of a simplified model as well as results from agent-based numerical simulations. Our findings suggest that, by adjusting call times and the amount of released pheromone, females can optimize the mating process. In particular, shorter calling times and lower pheromone titers at onset of the mating period that gradually increase over time allow females to aim for higher-quality males while still ensuring that mating occurs by the end of the mating period.

Key Amino Acid Residues Influencing Binding Affinities of Pheromone-Binding Protein from Athetis lepigone to Two Sex Pheromones.

Athetis lepigone is a polyphagous pest found around the world that feeds on maize, wheat, and various other important crops. Although it exhibits a degree of resistance to various chemical insecticides, an effective pest-control method has not yet been developed. The sex pheromone communication system plays an essential role in the mating and reproduction of moths, in which pheromone-binding proteins (PBPs) are crucial genes. In this study, we cloned and purified the protein AlepPBP1 using an E. coli expression system and found it had a higher binding affinity to two sex pheromones of A. lepigone, namely, Z7-12:Ac and Z9-14:Ac (with Ki 0.77 ± 0.10 and 1.10 ± 0.20 μM, respectively), than to other plant volatiles. The binding-mode analysis of protein conformation with equilibrium stabilization was obtained using molecular dynamics (MD) simulation and indicated that hydrophobic interactions involving several nonpolar residues were the main driving force for the binding affinity of AlepPBP1 with sex pheromones. Computational alanine scanning (CAS) was performed to further identify key amino acid residues and validate their binding contributions. Each key residue, including Phe36, Trp37, Val52, and Phe118, was subsequently mutated into alanine using site-directed mutagenesis. Binding assays showed that the efficient binding abilities to Z7-12:Ac (F36A, W37A, and F118A) and Z9-14:Ac (F36A, W37A, V52A, and F118A) were almost lost in the mutated proteins. Our results demonstrated that these key amino acid residues are crucial for determining the binding ability of AlepPBP1 to sex pheromones. These findings provide a basis for the use of AlepPBP1 in the studies as a specific target for the development of novel behavioral antagonists with marked inhibition or mating-disruption abilities using computer-aided drug design (CADD).

Ground application of mating disruption against the gypsy moth (Lepidoptera: Erebidae)

AbstractThe gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), is a non‐native defoliating insect that continues to expand its range in North America and undergo periodic outbreaks. In management efforts to suppress outbreaks, slow its spread and eradicate populations that arrive outside of the invaded range, aerial deployments of mating disruption tactics and pesticides are generally used. However, in some cases, such as in heavily urbanized areas or other landscapes where aerial deployments are not feasible or permitted, ground applications are required. Ground applications tend to be labour‐intensive to ensure adequate coverage. To better inform optimal deployment of ground applications of mating disruption, we measured the effectiveness of a pheromone formulation designed for ground application, SPLAT® GM, in forested areas of Virginia from 2011 to 2014 using different dosages and number of point applications. We observed that SPLAT® GM applied to the tree trunks at the dosages of 49.4 and 123.6 g AI/ha in 11 × 11 systematic grids (i.e., every 11 m) reduced male trap catch by >90% relative to untreated control plots, which based on previous studies corresponds to >95% reduction in gypsy moth mating success. Our observations suggest that ground applications of gypsy moth mating disruption can be a successful management tool when circumstances require it.

Transcriptome Analysis of Female and Male Conopomorpha sinensis (Lepidoptera: Gracilariidae) Adults With a Focus on Hormone and Reproduction.

Conopomorpha sinensis Bradley is the dominant borer pest of litchi and longan in the Asian-pacific area. Reduction or interference of reproduction and mating of adult moths is one of the most used strategies to control C. sinensis. Insect reproduction is a critical biological process closely related to endocrine control. Conopomorpha sinensis genome and transcriptome information is limited, hampering both our understanding of the molecular mechanisms underlying hormone activity and reproduction and the development of control strategies for this borer pest. To explore the sex differences in gene expression profiles influencing these biological processes, de novo transcriptomes were assembled from female and male adult C. sinensis specimens. This analysis yielded 184,422 unigenes with an average length of 903 bp and 405,961 transcripts after sequencing and assembly. About 45.06, 22.41, 19.53, 34.05, 35.82, 36.42, and 19.85% of the unigenes had significant matches in seven public databases. Subsequently, gene ontology (GO) and kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis revealed comprehensive information about the function of each gene and identified enriched categories and pathways that were associated with the 2,890 female-biased genes and 2,964 male-biased genes. In addition, we identified some important unigenes related to hormone activity and reproduction among the sex-differentially expressed genes (DEGs), including unigenes coding for ecdysone-induced protein 78C, juvenile hormone (JH)-regulated gene fatty acyl-CoA reductase, vitellogenin, etc. Our findings provide a more comprehensive portrait of the sex differences involved in the relationship of two important physiological features-hormone activity and reproduction in C. sinensis and members of the family Gracillariidae.

Relationship between efficacy of mating disruption and gypsy moth density

ABSTRACTMating disruption tactics involve the deployment of pheromones to interfere with mate finding behaviors in insect populations. This management strategy is the dominant one used against expanding gypsy moth populations in the United States, and historically it has been assumed to be most effective against low-density populations. Operationally, mating disruption is used in areas where the season-long trap catch is <30 males/trap, however the maximum population density at which mating disruption is effective remains unknown. We analysed historical gypsy moth mating disruption treatment data from 2000 to 2010, and used this information to guide the mating disruption field studies conducted from 2012 to 2015 against artificially-created populations of various densities, from 0 to 116 males/trap/day. We observed that mating disruption tactics at a dose of 15 g AI/ha were effective against gypsy moth populations with a season-long trap catch of at least 115 males/trap. This research highlights the utility of mating disruption in higher gypsy moth densities than what is currently recommended in management programs.

An Aerial Approach to Investigating the Relationship between Macromoths and Artificial Nighttime Lights Across an Urban Landscape

Urbanization represents a dramatic type of habitat change. Not only does it remove natural habitat for ecological communities, it also increases artificial nighttime light levels that can have negative impacts on night-flying species, such as moths. Feeding, mating and oviposition behaviors of moths can be affected by artificial nighttime lights, and they become more exposed to predators such as bats. In this study, an aerial approach was used to measure the prevalence of artificial nighttime light across an urban landscape (East Lansing, Michigan, USA). These light levels were related to macromoth species richness and abundance at 32 urban trapping sites. Both moth species richness and abundance were positively related to vegetation cover across the landscape, but there was no consistent, discernible impact of artificial nighttime light on either variable. This may be due to the lower attractiveness of high-pressure sodium lights that are used across this particular urban landscape, or to a negative association between the prevalence of landscape light levels and the amount of landscape vegetation. There is also a possibility that macromoths in urban areas have adapted to be less sensitive to light. This study is one of the first to use an aerial approach to measuring urban nighttime lights and departs from the most commonly held theory that increased light prevalence is associated with a depauperate moth assemblage.

Stability of Cacopsylla pyricola (Hemiptera: Psyllidae) Populations in Pacific Northwest Pear Orchards Managed with Long-Term Mating Disruption for Cydia pomonella (Lepidoptera: Tortricidae).

This study focused on conservation biological control of pear psylla, Cacopsylla pyricola, in the Pacific Northwest, USA. We hypothesized that insecticides applied against the primary insect pest, codling moth Cydia pomonella, negatively impact natural enemies of pear psylla, thus causing outbreaks of this secondary pest. Hence, the objective of this study was to understand how codling moth management influences the abundance of pear psylla and its natural enemy complex in pear orchards managed under long-term codling moth mating disruption programs. We conducted this study within a pear orchard that had previously been under seasonal mating disruption for codling moth for eight years. We replicated two treatments, “natural enemy disrupt” (application of two combination sprays of spinetoram plus chlorantraniliprole timed against first-generation codling moth) and “natural enemy non-disrupt” four times in the orchard. Field sampling of psylla and natural enemies (i.e., lacewings, coccinellids, spiders, Campylomma verbasci, syrphid flies, earwigs) revealed that pear psylla populations remained well below treatment thresholds all season despite the reduced abundance of key pear psylla natural enemies in the natural enemy disrupt plots compared with the non-disrupt treatment. We speculate that pear psylla are difficult to disrupt when pear orchards are under long-term codling moth disruption.

Comparison of invertebrate biodiversity in New Zealand apple orchards using integrated pest management, with or without codling moth mating disruption, or organic pest management

Abstract On-farm biodiversity is increasingly perceived as an indicator of sustainable practices. However, in-depth examinations of the influence of management on the components of this diversity (specific taxa, feeding guilds, pests, ecosystem service providers, native taxa, and so on) are still lacking for many crops and growing regions. To compare the diversity of invertebrates in commercial apple orchards using three different pest management systems (Integrated Fruit Production with or without codling moth mating disruption and certified organic), we collected taxa from five of each type of orchard in Hawke’s Bay, New Zealand. We used pitfall traps, branch tapping and sticky traps to collect 210,829 specimens, representing 764 taxa, during two sampling sessions: December 2011 and February/March 2012. Groundcover plant communities in the alleys between tree rows were not detectably different among the three orchard types. Multivariate analysis showed that the composition of invertebrate communities sampled from organic orchards differed significantly from those in orchards using the two different integrated pest management systems and that the use of codling moth disruption in the integrated systems had no discernible impact on invertebrate biodiversity in those orchards. Sub-group analysis revealed some differences between integrated and organic orchards for herbivores, predators and parasitoids, but not omnivores, detritivores and fungivores. Native or endemic species comprised 40% of taxa in all three orchard types, and there were no detectable differences in the composition of these assemblages among orchards. Assemblages of apple pests in organic orchards differed significantly from those in the other orchard types, but this effect was lost if Edwardsiana froggatti, which was abundant in organic orchards, was omitted from the analysis. All orchard types had similar assemblages of key natural enemies, suggesting that current integrated pest management systems employed on apple orchards in New Zealand have similar impacts to organic systems in this respect.

Capturing the economic value of biological control in western tree fruit

The economic value of biological control in apple in central Washington and pear in northern Oregon was estimated by comparing pest management programs following practices thought to reduce negative impacts on natural enemies to programs following traditional practices. Pest management costs in three apple orchards that had transitioned to the use of codling moth mating disruption (CMMD) plus reduced-risk or organophosphate-alternative pesticides were compared with four orchards that had not adopted these practices. Pest management costs in five pear orchards using CMMD were compared to four orchards not using CMMD. In both cropping systems the impact of pest management programs on biological control was determined by the need to use pesticides to control secondary pests, aphids and spider mites in apple and spider mites and pear psylla in pear. The disruptive nature of pesticides was categorized into four levels from none (0) to high (4) based on data presented by Mills et al. (2016) and Beers et al. (2016), as well as other published information. Some reduced-risk and OP-alternative pesticides proved detrimental to natural enemies and disruptive of biological control in apple and pear. In apple, the use of pesticides with low risk to natural enemies reduced the need to apply controls for secondary pests. In pear, the use of CMMD reduced the need to control secondary pests, spider mites and pear psylla, in summer. The use of pesticides with a high risk to natural enemies increased the cost of secondary pest control by about 50% in apple and pear. A stepwise increase in natural enemy risk values increased total pest management costs by $46/ha in natural enemy unfavorable apple orchards and by $44/ha in pear orchards not using codling moth mating disruption.

Resurgence of minor pests following the implementation of mating disruption against "Lobesia botrana" (Denis & Schiffermüller) (Lepidoptera, Tortricidae) in Sherry vineyards (Spain)

The implementation of the mating disruption technique against the grape berry moth, Lobesia botrana (Denis and Schiffermuller) (Lepidoptera, Tortricidae), in Integrated Pest Management (IPM) Sherry vineyards (Andalusia, Southwestern Spain) reduced the number of chemical treatments required to manage this serious pest. In order to verify the long term consequences of this type of management on the secondary pests of vineyards, a study was carried out over nine years to compare the population levels of four phytophagous insect species ( Altica ampelophaga, Planococcus citri , Jacobiasca lybica , Aphis gossypii ) in plots where L. botrana was managed with conventional chemical treatments or using mating disruption. Field data on secondary pests were collected on randomly chosen vines at different times on different plant organs such as leaves, shoots and bunches, depending on the type of pest, according to the ATRIA procedure (Andalusian IPM procedure). Results showed a significant increase of grapevine infestation by all four secondary pest species in the plots managed with grape berry moth mating disruption. These findings represented a limitation for the implementation of this technique in Andalusian vineyards.

Fed males increase oviposition in female hawkmoths via non-nutritive direct benefits

Direct benefits provided by males have large effects on the fitness of females and their offspring in many species. Here, we examined whether mating or feeding experience of male Carolina sphinx moths, Manduca sexta (Sphingidae), affects the quality of direct benefits that males provide to their mates. We mated virgin females with fed and unfed, virgin and previously mated males. Feeding experience affected male mating success, spermatophore size and flight muscle size. In addition, females mated to fed males laid more eggs than females mated to unfed males, and females mated to virgin males laid more eggs than females mated to previously mated males. Using 13C-enriched glucose in the nectar of the fed males, we found that the second and third spermatophores of males were strongly labelled, but this labelled glucose was not present either in the female's fat body or in her eggs. Therefore, although fed males provided females direct benefits from the sugar in the nectar, the sugar was not used as a nutrient by females. We suggest that in short-lived species, where females mate singly and males mate multiply, and where nectar availability is highly variable, males may be selected to conserve their resources to maintain flight capability and to invest in sperm performance and, thus, provide only limited (non-nutritive) direct fitness benefits to their mates.

Effects of X-Ray Irradiation on Male Navel Orangeworm Moths (Lepidoptera: Pyralidae) on Mating, Fecundity, Fertility, and Inherited Sterility.

Male adult navel orangeworm, Amyelois transitella (Walker), were irradiated using a laboratory scale x-ray irradiation unit to determine the required dose for complete egg sterility of mated female moths and inherited sterility of F1 and F2 generations. Adult male A. transitella were irradiated in two separate experiments at 100-300 Gy and 50-175 Gy. Mating frequency, fecundity, and fertility of normal females crossed with irradiated parental males was compared with the mating of nonirradiated moths. Mating frequency was 100% for females crossed with nonirradiated control males. At male treatment doses of ≥150 Gy the percentage of females found unmated increased, while multiple-mated females decreased. Female fecundity was not affected while fertility was affected in a dose-dependent relationship to exposure of parental males to x-ray irradiation. Embryonic development of eggs to the prehatch stage and egg eclosion did not occur at radiation doses ≥125 Gy. Emergence of F1 adults was low and occurred only for progeny of parental males exposed to doses ≤100 Gy, with no emergence at ≥125 Gy. Though fecundity appeared similar for control and irradiated F1 females, no F2 eggs hatched for the test exposures of 50-100 Gy. Based on our results, a dose of ≥125 Gy had efficacy in inducing both primary parental sterility in treated male moths and inherited sterility in F1 male and female moths. Results suggest that A. transitella might be considered a candidate for the sterile insect technique using adults irradiated at these relatively low x-ray exposure doses.

TUTA ABSOLUTA (MEYRICK, 1917) (LEPIDOPTERA GELECHIIDAE) ADULT FEEDING ON TOMATO LEAVES. NOTES ON THE BEHAVIOUR AND THE MORPHOLOGY OF THE PARTS RELATED.

Introduction: The Tomato Leaf Miner, Tuta absoluta (Meyrick) (Lepidoptera Gelechiidae), is actually a most dangerous pest of solanaceous crops. Aims: While demonstrating the Tomato Leaf Miner adults, both male and female, ability to feed on tomato leaves we report an unexpected behaviour for this microlepidoptera. This paper details also morphological adaptation of the proboscis involved in feeding and evidences of the action on the leaves. Materials and Methods: Observation were given by digital camera-equipped stereoscope and Cryo-SEM. Results: We discuss the mean of adult feeding in respect to moth mating and egg laying. A possible use of adult feeding in Tomato Leaf Miner IPM is also discussed. Discussion and conclusions: The adult Tomato Leaf Miner is capable to feed by wounding tomato leaf by its proboscis.