Larval Structures Research Articles

Photocatalytic activity of TiO2-Carbon nanocomposite films against Culex pipiens mosquito larvae under sunlight irradiation

Recent research has focused on developing eco-friendly nanomaterials to combat mosquito infestations. This study demonstrates the enhancement of titanium dioxide (TiO2) nanoparticles through the addition of carbon nanoparticles (C-NPs), significantly boosting their photocatalytic efficiency. This enhancement allows TiO2 to purify water and act as an effective pesticide. Formulated TiO2-carbon (TiO2–C) nanocomposite films showed increased photocatalytic activity against third-instar larvae of Culex pipiens under natural sunlight. The addition of C-NPs improved sunlight absorption and reduced electron-hole recombination rates compared to pristine TiO2 (P–TiO2), making it more effective for mosquito control. The superior performance of the TiO2–C nanocomposite was confirmed through X-ray Photoelectron Spectroscopy (XPS), UV–vis diffuse reflectance spectra (UV–vis DRS), and Photoluminescence emission (PL). These analyses confirmed successful carbon incorporation, expanding the absorption spectrum and enhancing optical properties. The UV–vis DRS spectra showed a decrease in the bandgap energy (Eg) of P–TiO2 from 3.2 eV to 3.1 eV, improving its photocatalytic effectiveness under natural sunlight. Bioactivity tests, including catalase activity, reduced glutathione (GSH) colorimetric assay, and superoxide dismutase (SOD) assay, along with microscopic and histological examinations of treated larvae, indicated that the TiO2–C nanocomposite effectively reduces the mosquito population and causes significant physiological damage and abnormalities in larval structures and midgut cells. These findings highlight the enhanced photocatalytic capabilities of the TiO2–C nanocomposite, making it a novel and effective solution for mosquito control with significant public health and environmental benefits.

Organogenetic transcriptomes of the Drosophila embryo at single cell resolution.

To gain insight into the transcription programs activated during the formation of Drosophila larval structures, we carried out single cell RNA sequencing during two periods of Drosophila embryogenesis: stages 10-12, when most organs are first specified and initiate morphological and physiological specialization; and stages 13-16, when organs achieve their final mature architectures and begin to function. Our data confirm previous findings with regards to functional specialization of some organs - the salivary gland and trachea - and clarify the embryonic functions of another - the plasmatocytes. We also identify two early developmental trajectories in germ cells and uncover a potential role for proteolysis during germline stem cell specialization. We identify the likely cell type of origin for key components of the Drosophila matrisome and several commonly used Drosophila embryonic cell culture lines. Finally, we compare our findings with other recent related studies and with other modalities for identifying tissue-specific gene expression patterns. These data provide a useful community resource for identifying many new players in tissue-specific morphogenesis and functional specialization of developing organs.

Seasonal contrast of water masses and larval fish habitats at the entrance of the Gulf of California

Based on satellite and in situ data and larval fish distributions obtained from two cruises during April 2012 (cold period) and September 2016 (warm period), larval fish habitats were analyzed in relation to the water masses that converge at the entrance of the Gulf of California. The distribution of environmental variables and the ocean upper layer water masses showed a clear-cut seasonal contrast. During April 2012, the Gulf of California Water extended southward to ∼21oN, while in September 2016, the Transitional Water expanded northward to ∼23oN to dominate the entrance of the Gulf of California as the Gulf of California Water retreated to the interior gulf. In addition, mesoscale eddies were frequently observed in both periods, mostly cyclonic in April 2012, and anticyclonic in September 2016. Multivariate analyses defined two larval fish habitats in each period: North and South of a boundary between 22 and 22.5oN. The larval structure of the North larval fish habitat varied in both composition and abundance between periods, although the dominant species in both periods were Vinciguerria lucetia above the thermocline and Diogenichthys laternatus in the layer beneath the thermocline. These species had a higher abundance in April 2012 than in September 2016. The South larval fish habitats also had differences in their larval structures in the two periods, but Bregmaceros bathymaster was the dominant species, with the highest abundance in April 2012. The definition of the larval fish habitats and their changes in structure were associated with the seasonal contrast of the water masses, but the limits of the larval fish habitats were modulated by the mesoscale structures. The spawning of most species is seasonally controlled, but the dominant ones showed signs of resilience to environmental changes. This study displayed the influence of two different environmental scales on the fish larvae community, which might be a pattern in other regions of water mass convergence.

The supraspecific structure of the subtribe Blaptina Leach, 1815 (Coleoptera, Tenebrionidae: Blaptinae)

Years of research of the subtribe Blaptina made it possible to clarify relations between some species and propose changes in supraspecific structure of this subtribe. Blaps scabiosa Baudi di Selve, 1874 is designated as a type species of Caraboblaps Bauer, 1921, the new synonymy is proposed: Blaps Fabricius, 1775 = Caraboblaps Bauer, 1921, syn. n. Blaps nitens nitens Laporte, 1840 is designated as a type species of Periblaps Bauer, 1921, Blaps ominosa Ménétriés, 1832 is designated as a type species of Holoblaps Bauer, 1921; type species of Periblaps and Holoblaps are transferred here to genus Lithoblaps, as a result the following new synonymy is proposed: Lithoblaps Motschulsky, 1860 = Periblaps Bauer, 1921, syn. n. = Holoblaps Bauer, 1921, syn. n. The similarity of the structure of the aedeagus of Ablapsis compressipes Reitter, 1887 and some species of the subgenus Prosoblapsia Skopin et Kaszab, 1978 (genus Blaps Fabricius, 1775) gives a base to transfer the taxon Ablapsis Reitter, 1887 into the genus Blaps as a separate subgenus (Ablapsis stat. resurr.). Blaps tentyrioides Seidlitz, 1893 (= Blaps socia Seidlitz, 1893) is designated as a type species of the subgenus Protoblaps Bauer, 1921. As the genera Protoblaps Bauer, 1921 and Genoblaps Bauer, 1921 have one type species and the aedeagal structure of type species of Ablapsis, Protoblaps and Prosoblapsia is similar, the new synonymy is proposed: Ablapsis Reitter, 1887 = Protoblaps Bauer, 1921 syn. n. = Genoblaps Bauer, 1921 syn. n. = Prosoblapsia Skopin et Kaszab, 1978, syn. n. Analysis of imaginal and larval structures of the species here united in the taxon Lithoblaps Motschulsky, 1860 and other members of Blaps showed that differences between these two groups are comparable with those between other genera of the subtribe and, therefore, the former taxon is here regarded as a distinct genus Lithoblaps gen. resurr. Thus, 100 species and subspecies (marked as comb. n. or comb. resurr.) are transferred from Blaps to Lithoblaps. The additional new combination is established: Dila platythorax (Gemminger, 1870), comb. n. (from Blaps). The key to genera and the catalogue of the subtribe Blaptina are given.

Mangosteen Garcinia mangostana L. simplicia effect on bone structure and behaviour of Wader Fish Rasbora lateristriata (Bleeker, 1854) Embryo

Mangosteen (Garcinia mangostana L.) is a fruit originating from the tropics which belongs to the Clusiaceae family and has become a commodity with many enthusiasts from various countries. Previous research has shown that mangosteen peel extract has tremendous potential to be developed as an ingredient in herbal medicine. Mangosteen fruit contains anti-inflammatory, antibacterial, antifungal, antihistamine, antidiabetic, anticancer, and so on. The results of the phytochemical screening test of 95% ethanol extract on mangosteen rind showed that it contained flavonoid compounds, saponins, alkaloids, triterpenoids, tannins and polyphenols. There is no data on the effect of exposure to mangosteen pericarip simplicia, therefore it is necessary to study the effect of exposure to mangosteen peel decoction on animal models of Wader Pari Fish (Rasbora lateristriata), with parameters such as morphology and bone structure in larvae wader fish (Rasbora lateristriata). Alcian Blue Alizarin Red staining were used to study bone structure in wader fish (Rasbora lateristriata). Data were statistical analysis with SPSS ver. 25 and the significance was determined using one-way analysis of variance (ANOVA). The morphological examination results revealed that the embryo and larvae had no morphological abnormalities. The cranial cartilage examination also revealed that the larvae had no abnormalities, the length and the angle of the cranial cartilage did not change between the control and mangosteen pericarp simplicia treatment.

Molecular and cellular architecture of the larval sensory organ in the cnidarian Nematostella vectensis.

ABSTRACTCnidarians are the only non-bilaterian group to evolve ciliated larvae with an apical sensory organ, which is possibly homologous to the apical organs of bilaterian primary larvae. Here, we generated transcriptomes of the apical tissue in the sea anemone Nematostella vectensis and showed that it has a unique neuronal signature. By integrating previously published larval single-cell data with our apical transcriptomes, we discovered that the apical domain comprises a minimum of six distinct cell types. We show that the apical organ is compartmentalised into apical tuft cells (spot) and larval-specific neurons (ring). Finally, we identify ISX-like (NVE14554), a PRD class homeobox gene specifically expressed in apical tuft cells, as an FGF signalling-dependent transcription factor responsible for the formation of the apical tuft domain via repression of the neural ring fate in apical cells. With this study, we contribute a comparison of the molecular anatomy of apical organs, which must be carried out across phyla to determine whether this crucial larval structure evolved once or multiple times.

Finding a pathway through the rocks: the role of development on the evolution of quasi-terrestriality and the origin of endotrophism in cycloramphids (Anura)

AbstractAnurans have served as models in evolutionary studies on reproduction and development. Several generalizations have emerged but it is unclear whether they represent the diversity of the entire group. We studied the development of two species of the Neotropical family Cycloramphidae. Frogs in this family have peculiar spawning sites and developmental biologies. Whereas some cycloramphid tadpoles are exotrophic, quasi-terrestrial and thrive in films of water that flow over rocky outcrops, others are endotrophic, terrestrial and complete their development outside the eggs laid on the forest floor, under logs or in crevices. Cycloramphid tadpoles have aspects of their morphology distinct from those of pond and stream dwellers; they hatch in more advanced stages of development and have typical tadpole structures, either in a modified form or absent. Herein we present a study of the tadpoles of C. lithomimeticus and T. miliaris, in order to document and discuss alterations in the ontogeny of several larval structures. These changes seem to be associated with adaptations to life in the peculiar habitats where the tadpoles thrive. We infer that the observations we present are explained by development being associated with aspects of terrestrialization and endotrophism.

Deformation of Mentum Structure in Larvae of Chironomidae (Diptera: Chironomidae) in the Chi River Basin, Thailand

Deformation of Mentum Structure in Larvae of Chironomidae (Diptera: Chironomidae) in the Chi River Basin, Thailand

Early development of pearlside Maurolicus stehmanni off south-eastern Brazil.

The pearlside Maurolicus stehmanni is one of the most abundant mesopelagic fishes off south-eastern Brazil and plays a key role in the regional ecosystem. However, its early life history remains poorly understood. This study examined the M. stehmanni early life stages, from eggs to juveniles, including all developmental changes in external morphology. Larvae are simple in morphology and lack specialized larval structures. Notochord flexion begins at ~5.15 mm body length (BL) and larvae ≥5.95 mm BL are flexed. The relative growth of seven measured larval characters (head length, body depth, snout length, eye diameter, pre-dorsal length, pre-ventral length and pre-anal length) have transition points (allometric inflexion points), indicating biphasic growth patterns which are likely related to shifts in habitat use, feeding and behaviour. Larval development is similar to that of other Maurolicus species. The relatively fast development of the fins, photophores, swimbladder and pigmentation suggests a precocious adoption of a micronektonic lifestyle in the mesopelagic environment.

Larval Structures and Bionomics of Two Species of the Genus Intybia Pascoe (Coleoptera: Melyridae: Malachiinae)

Malachiine beetles characteristically show “foetometamorphosis” during their life cycles, in which the first larval instar is inactive and nonfeeding. However, its adaptive significance has yet to be elucidated. The adaptive significance of hypermetamorphosis, another type of holometamorphosis characterized by a dramatic change of larval morphology from triungulin to eruciform larval stages, has been suggested to include protection, combat, host finding, foraging, and food acquisition. Given these observations from hypermetamorphosis, it is possible that foetometamorphosis is also related to the life cycle, foraging requirements, and larval structure of malachiine beetles; however, biological data on this matter is lacking. In this paper, the mature larval structures, bionomics and life cycles of Intybia pelegrini pelegrini (Pic, 1910) and Intybia takaraensis (Nakane, 1955) are presented for the first time. Based on observations, the unusual larval developmental pattern for both species is discussed.

The larval structures and bionomics of Idgia iriomoteana (Coleoptera: Prionoceridae)

The life cycle, bionomics and mature larval structures of the Japanese prionocerid species, Idgia iriomoteana Nakane, 1980 were investigated in captivity. The results showed that I. iriomoteana has the following characteristics: (1) the larval morph is less advanced in terms of miniaturization, and larvae pass seven larval molts before they pupate; (2) the life cycle is univoltine with summer, not winter, dormancy; (3) the first instar larvae are larger than the size of the egg, but foetomorphic larval instar (which is observed in the Melyridae: Malachiinae) is not shown. Based on comparison with melyrid species, the degree of miniaturization, dormancy behaviour, adaptation to the tropical and subtropical climates and the adaptive significance of a large first instar larva are all discussed. This study is the first to report the complete life cycle of a member of the family Prionoceridae.

Allometric growth in larval and juvenile blackhead seabream Acanthopagrus schlegelii (Bleeker, 1854) (Peciformes: Sparidae)

Allometric growth in larvae and juvenile blackhead seabream Acanthopagrus schlegelii (Bleeker, 1854) was studied. In the larval head, snout length, snout-gill slit distance, interocular distance and mouth width showed positive allometric growth, while eye diameter and head height showed negative allometric growth. In the head of juveniles, interocular distance and mouth width showed negative allometric growth, while all other organs showed positive allometric growth. In larval body, body thickness showed positive allometric growth, while all other body parts showed negative allometric growth. In the juvenile body, caudal peduncle length, caudal peduncle height and body thickness showed positive allometric growth, while head length, body height, trunk length and tail length showed negative allometric growth. All of the larval swimming structures (the dorsal fins, pectoral fins, pelvic fins, anal fins and caudal fins) showed positive allometric growth. The rapid development of key organs in the blackhead seabream after the initiation of exogenous nutrition allows for a significant increase in viability with minimal metabolic loss. The information generated through this study can provide a framework for understanding how blackhead seabream responds developmentally to challenging external pressures during their early life.

New record of Brachycyrtus Kriechbaumer, 1880 (Hymenoptera: Ichneumonidae) from Venezuela and notes about their association with some chrysopid species

Brachycyrtus pretiosus Cushman, 1936 is recorded from Venezuela for the first time. The green-lacewings species Ceraeochrysa valida (Banks, 1851) and Ceraeochrysa fairchildi (Banks, 1946) are considered as the first known recorded hosts of Brachycyrtus cosmetus (Walkley, 1956). Illustrations of the studied Brachycyrtus spp. Adults, final larval instar cephalic structures of B. cosmetus and maps with geographical distribution are provided.

Bivalves are NO different: nitric oxide as negative regulator of metamorphosis in the Pacific oyster, Crassostrea gigas

BackgroundNitric oxide (NO) is presumed to be a regulator of metamorphosis in many invertebrate species, and although NO pathways have been comparatively well-investigated in gastropods, annelids and crustaceans, there has been very limited research on the effects of NO on metamorphosis in bivalve shellfish.ResultsIn this paper, we investigate the effects of NO pathway inhibitors and NO donors on metamorphosis induction in larvae of the Pacific oyster, Crassostrea gigas. The nitric oxides synthase (NOS) inhibitors s-methylisothiourea hemisulfate salt (SMIS), aminoguanidine hemisulfate salt (AGH) and 7-nitroindazole (7-NI) induced metamorphosis at 75, 76 and 83% respectively, and operating in a concentration-dependent manner. Additional induction of up to 54% resulted from exposures to 1H-[1,2,4]Oxadiazole[4,3-a]quinoxalin-1-one (ODQ), an inhibitor of soluble guanylyl cyclase, with which NO interacts to catalyse the synthesis of cyclic guanosine monophosphate (cGMP). Conversely, high concentrations of the NO donor sodium nitroprusside dihydrate in combination with metamorphosis inducers epinephrine, MK-801 or SMIS, significantly decreased metamorphosis, although a potential harmful effect of excessive NO unrelated to metamorphosis pathway cannot be excluded. Expression of CgNOS also decreased in larvae after metamorphosis regardless of the inducers used, but intensified again post-metamorphosis in spat. Fluorescent detection of NO in competent larvae with DAF-FM diacetate and localisation of the oyster nitric oxide synthase CgNOS expression by in-situ hybridisation showed that NO occurs primarily in two key larval structures, the velum and foot. cGMP was also detected in the foot using immunofluorescent assays, and is potentially involved in the foot’s smooth muscle relaxation.ConclusionTogether, these results suggest that the NO pathway acts as a negative regulator of metamorphosis in Pacific oyster larvae, and that NO reduction induces metamorphosis by inhibiting swimming or crawling behaviour, in conjunction with a cascade of additional neuroendocrine downstream responses.

Programmed cell death reshapes the central nervous system during metamorphosis in insects.

Metamorphosis is fascinating and dramatic stage of postembryonic development in insects [1]. The most prominent metamorphic changes seen in holometabolous insects involve destruction of most larval structures and concomitant generation of adult ones. Such diverse cellular events are orchestrated by ecdysone. The central nervous system (CNS) is also extensively remodeled to process new sensory inputs; to coordinate new types of locomotion; and to perform higher-order decision making [2]. Programmed cell death (PCD) is an integral part of the metamorphic development. It eliminates obsolete larval tissues and extra cells that are generated from the morphogenesis of adult tissues. In the CNS, PCD of selected neurons and glial cells as well as reshaping of persistent larval cells are essential for establishing the adult CNS. In this review, we summarize the ecdysone signaling, and then molecular and cellular events associated with PCD primarily in the metamorphosing CNS of Drosophila melanogaster.

Nomenclatural changes in Centroptella Braasch & Soldán, 1980 (Ephemeroptera, Baetidae).

The genus Centroptella Braasch & Soldán, 1980 is accepted here in a wide sense, i.e., including Chopralla Waltz & McCafferty, 1987. This genus concept is similar to the concept of the genus Bungona Harker, 1957 proposed by Salles et al. (2016), but with the generic name Centroptella instead of Bungona. The type species of Bungona, B. narilla Harker, 1957, has an unknown systematic position; the neotype designation proposed by Suter and Pearson (2001) is invalid, being inconsistent with the International Code of Zoological Nomenclature; the species name B. narilla and the generic name Bungona are nomina dubia, so the name Centroptella is the senior name for the genus under consideration. The generic names Chopralla and Crassolus Salles, Gattolliat & Sartori, 2016 both are junior synonyms of Centroptella (syn. nov.). The subgenera Bungona, Centroptella and Chopralla proposed by Salles et al. (2016) are unnatural. The following new combinations are proposed: Centroptella bintang (Marle, Salles & Gattolliat, 2016) comb. nov., Centroptella bifida (Shi & Tong, 2019) comb. nov., Centroptella fusina (Tong & Dudgeon, 2003) comb. nov., Centroptella fustipalpus (Lugo-Ortiz & McCafferty, 1998) comb. nov., Centroptella illiesi (Lugo-Ortiz & McCafferty, 1998) comb. nov., Centroptella inzingae (Crass, 1947) comb. nov., Centroptella papilionodes (Marle, Salles & Gattolliat, 2016) comb. nov., Centroptella pontica (Sroka, Godunko & Gattolliat, in Sroka et al. 2019) comb. nov., Centroptella ovata (Shi & Tong, 2019) comb. nov., Centroptella quadrata (Shi & Tong, 2019) comb. nov. and Centroptella saxophila (Agnew, 1961) comb. nov. The two Australian species, C. fustipalpus and C. illiesi, differ from each other in the shape of tergalii; corrections to the original description of C. fustipalpus are given based on re-examination of the holotype and paratypes; details of larval structures of C. illiesi are figured. Corrections to the former descriptions of the South African species C. inzingae and C. saxophila are given. Examination of type material led to the discovery that the original description of the Oriental species Centroptella liebenauae Soldán, Braasch & Muu, 1987 was based on two different species: the descriptions of imago and subimago belong to Centroptella longisetosa Braasch & Soldán, 1980 (the type species of Centroptella), and the description of larva belongs to a different species, which we describe here as Centroptella ingridaesp. nov. The holotype of C. liebenauae, a larva, should be considered lost; based on the date of collection, it belonged to C. longisetosa; a set of larval exuviae with the same collecting data as the holotype, is designated as the neotype of C. liebenauae, and a new synonymy is established: C. longisetosa = C. liebenauaesyn. nov. The larvae originally assigned to C. liebenauae are placed to a new species Centroptella ingridaesp. nov. belonging to the inzingae-ingridae species group; all stages of development of this species are described based on male and female imagines reared from larvae in Thailand and on the misidentified paratypes of C. liebenauae from Vietnam. Centroptella longisetosa is redescribed based on the single paratype from China, the neotype and paratypes of C. liebenauae from Vietnam, and additional material from India. Additional data on the holotype of Centroptella colorata Soldán, Braasch & Muu, 1987 are given.

English

English

Foregut Development and Metamorphosis in a Pyramidellid Gastropod: Modularity and Constraint within a Complex Life Cycle.

Pyramidellids are tiny ectoparasitic gastropods with highly derived feeding structures for piercing and sucking. We attempted to resolve homology controversies about unique pyramidellid feeding structures by examining foregut development through larval and metamorphic stages, using sections for light and electron microscopy. We anticipated that, like many marine invertebrate larvae, post-metamorphic structures would differentiate extensively in late larvae to speed metamorphic transition. Previous studies of gastropods suggested that development of juvenile feeding structures in larvae was facilitated by foregut subdivision into dorsal and ventral developmental modules, and spatial uncoupling of these modules may have facilitated adaptive radiation in neogastropods. Observations of Odostomia tenuisculpta suggested that the stylet may be derived from cuticle-secreting buccal epithelium surrounding the proximal end of the salivary duct, whereas the stylet sheath could be either a derived jaw or a radular tooth. The anterior half of the remarkable buccal pump of these euthyneuran gastropods develops from the larval esophagus, which is unorthodox compared to caenogastropods, where extensive post-metamorphic specialization of a dorsal module component has not been previously described. The introvert tube develops from pouches of the distal larval esophagus and may actually be an eversible oral tube rather than an acrembolic proboscis. Minimal differentiation of presumptive juvenile foregut structures occurred during the larval stage of O. tenuisculpta, when compared to other gastropods. The stylet, stylet sheath, and buccal pump may be incompatible with functioning of the larval esophagus; thus, an explosive period of morphogenesis is necessary at metamorphosis. Although dorsal and ventral modules were recognizable during the development of O. tenuisculpta, we failed to find evidence that this modularity facilitated the extreme evolutionary remodeling of post-metamorphic feeding structures.

The using of morphometric indices in the identification of mosquito larvae of the genus Aedes Meigen, 1818 (Diptera, Culicidae) of fauna of Ukraine

As a result of the morphometric analysis on the mosquito larval structures of the genus Aedes Meigen, 1818 from our own collections and literature analyses, a wide variation in quantitative and qualitative indices was revealed. The morphological and metric indices of mosquito larvae are quite similar and vary under the influence of environmental factors, which must be taken into account when determining species. The tables for rapid determination of common mosquito species of Ukraine, with the use of external features that do not require the manufacture of permanent slide mounts, are given in the article. All modern keys for identification are based on dichotomous tables. This process is quite long, does not take into account the individual variability and does not allow the quick identification of species. After analyzing the literature and summing up the result, it can be confirmed that 35 species of bloodsucking mosquitoes of the genus Aedes occur within Ukraine, so there is a need to create a new regional key. The purpose of the study is to propose tables for determining the common mosquitoes of the genus Aedes in Ukraine using external morphometric characteristics. The material used for this study was collected by the author in March–October of 2017–2018 at the territory of Volyn Region. Over the entire study period, a total of 185 samples were collected, 1580 species of mosquito larvae of the genus Aedes were analyzed. During the work, 12 morphometric characters of bloodsucking mosquitoes were used and the results were tabulated to determine species of the genus Aedes. The proposed keys for definition are presented in the form of a tables and have certain advantages, such as, the ability not to take into account the characters lost in the process of collecting or storing and to complete the diagnostics on other features, that is quite problematic with the dichotomous keys, since they have a certain algorithms. The proposed tables are based on the using of quantitative and qualitative external characters and do not require the preparation of slide mounts in further work. There is also the possibility of creating an electronic key, which will greatly facilitate the work on the determination of the larvae in the genus Aedes.

Inverse resource allocation between vision and olfaction across the genus Drosophila

Divergent populations across different environments are exposed to critical sensory information related to locating a host or mate, as well as avoiding predators and pathogens. These sensory signals generate evolutionary changes in neuroanatomy and behavior; however, few studies have investigated patterns of neural architecture that occur between sensory systems, or that occur within large groups of closely-related organisms. Here we examine 62 species within the genus Drosophila and describe an inverse resource allocation between vision and olfaction, which we consistently observe at the periphery, within the brain, as well as during larval development. This sensory variation was noted across the entire genus and appears to represent repeated, independent evolutionary events, where one sensory modality is consistently selected for at the expense of the other. Moreover, we provide evidence of a developmental genetic constraint through the sharing of a single larval structure, the eye-antennal imaginal disc. In addition, we examine the ecological implications of visual or olfactory bias, including the potential impact on host-navigation and courtship.