Number Of Ovarioles Research Articles

Prey life-history influences the evolution of egg mass and indirectly reproductive investment in a group of free-living insect predators.

The balance between risk and benefit of exploiting resources drives life‐history evolution in organisms. Predators are naturally recognized as major drivers of the life‐history evolution of their prey. Although prey may also influence the life‐history evolution of their predators in the context of an evolutionary arms race, there is far more evidence of the role of predators than of prey.The goal of this study was to investigate the role of prey in life‐history evolution of predators using ladybird beetle predators of aphids and coccids. These particular ladybirds and their prey were chosen because literature shows that the pace of life of aphids is faster than that of coccids and this difference is reflected in the life histories of the ladybirds that specialize on feeding on aphids or coccids.Thirty‐four species of ladybird predators of aphids and eight of coccids belonging to five different tribes were collected and reared in the laboratory. The females were weighed as well as their eggs, and their reproductive investment estimated as the number of ovarioles. Phylogenetic relatedness was controlled for in the statistical analyses.Controlling for female mass revealed that ladybird predators of aphids lay bigger eggs than ladybird predators of coccids. This difference is not influenced by phylogenetic relatedness but only by the type of prey eaten. We suggest that ladybird predators of coccids lay smaller eggs because neonate larvae do not have to search, catch, and subdue prey. Both types of ladybirds have a similar reproductive investment relative to their body mass when phylogeny is controlled for.Recognizing the influence of prey on the life‐history evolution of predators is important for understanding food web dynamics. From an applied perspective, this fine evolutionary tuning of prey–predator relationships should be used to guide and increase the efficiency of biological control programs.

Attack of the dark clones the genetics of reproductive and color traits of South African honey bees (Apis mellifera spp.).

The traits of two subspecies of western honey bees, Apis mellifera scutellata and A.m. capensis, endemic to the Republic of South Africa (RSA), are of biological and commercial relevance. Nevertheless, the genetic basis of important phenotypes found in these subspecies remains poorly understood. We performed a genome wide association study on three traits of biological relevance in 234 A.m. capensis, 73 A.m. scutellata and 158 hybrid individuals. Thirteen markers were significantly associated to at least one trait (P ≤ 4.28 × 10-6): one for ovariole number, four for scutellar plate and eight for tergite color. We discovered two possible causative variants associated to the respective phenotypes: a deletion in GB46429 or Ebony (NC_007070.3:g.14101325G>del) (R69Efs*85) and a nonsense on GB54634 (NC_007076.3:g.4492792A>G;p.Tyr128*) causing a premature stop, substantially shortening the predicted protein. The mutant genotypes are significantly associated to phenotypes in A.m. capensis. Loss-of-function of Ebony can cause accumulation of circulating dopamine, and increased dopamine levels correlate to ovary development in queenless workers and pheromone production. Allelic association (P = 1.824 x 10-5) of NC_007076.3:g.4492792A>G;p.Tyr128* to ovariole number warrants further investigation into function and expression of the GB54634 gene. Our results highlight genetic components of relevant production/conservation behavioral phenotypes in honey bees.

Reproductive Potential Impacts Body Maintenance Parameters and Global DNA Methylation in Honeybee Workers (Apis mellifera L.)

Simple SummaryThe queens and sterile workers arise from genetically identical eggs but as imagoes, they differ in their life span, DNA methylation, and their functions. In the absence of the queen, the larvae develop into rebels, i.e., workers with increased reproductive potential. We assumed that since rebels are similar to the queen in many anatomical and behavioral features, they live longer and have lower levels of global DNA methylation, even when infected, e.g., by Nosema spp. Rebels always lived longer in comparison in normal workers and unexpectedly extended longevity of normal workers when they were together, similarly as the presence of a queen did. Rebels became infected more easily but tolerated the infection better. They also had lower level of global DNA methylation than normal workers. These features expand possibilities of the use of honeybees as a model for studies on senescence, nosemosis, eusocial evolution, and epigenetics.The widely accepted hypothesis in life history evolution about the trade-off between fecundity and longevity is not confirmed by long-living and highly fecund queens in eusocial insects. The fact that the queens and facultatively sterile workers usually arise from genetically identical eggs but differ in DNA methylation makes them a good model for studies on senescence, eusocial evolution, and epigenetics. Therefore, honeybees seem to be especially useful here because of long living rebel-workers (RW) with high reproductive potential recently described. Longevity, ovariole number, nosema tolerance, and global DNA methylation have been assayed in normal workers (NW) versus RW in hives and cages. RW always lived longer than NW and unexpectedly extended longevity of NW when they were together, similarly as the presence of a queen did. RW lived longer despite the fact that they had higher Nosema spore load; surprisingly they became infected more easily but tolerated the infection better. Global DNA methylation increased with age, being lower in RW than in NW. Therefore, RW are queen-like considering global DNA methylation and the link between fecundity, longevity, and body maintenance. Presented features of RW expands possibilities of the use of honeybees as a model for studies on senescence, nosemosis, eusocial evolution, and epigenetics.

Investigating Genetic and Phenotypic Variability of Queen Bees: Morphological and Reproductive Traits

Simple SummaryHoneybees have attracted considerable scientific and public interest in recent years. Besides pesticides and pathogens, failure or loss of the queen have been considered the most important factors leading to colony losses worldwide. The poor quality of the queen is a factor that ranks among the top reasons for bee colony failure. There are traits that can indicate the quality of a queen bee. This study aims to investigate the diversity in reproductive and morphological traits that can be useful in selective breeding programs for improving colony performance and survivability. The studied animals came from a population bred by a professional queen breeder in Northern Italy. Heritability and genetic correlations were estimated. According to our results, some of the traits showed good variability and they could be included as breeding goals in selection programs. Improving the quality of queens could directly impact honeybee colonies’ performance and survivability. Ultimately, it represents an added value to a queen bee-breeder company.The quality of the honeybee queen has an important effect on a colony’s development, productivity, and survival. Queen failure or loss is considered a leading cause for colonies’ mortality worldwide. The queen’s quality, resulting from her genetic background, developmental conditions, mating success, and environment, can be assessed by some morphological measures. The study aims to investigate variability for traits that could assess the quality of the queen. Related animals were enrolled in this study. Variance components were estimated fitting a mixed animal model to collected data. Heritabilities of body and tagmata weights ranged from 0.46 to 0.54, whereas lower estimates were found for the tagmata width and wing length. Heritabilities estimated for the spermatheca diameter and volume, number of ovarioles, and number of sperms were 0.17, 0.88, 0.70, and 0.57, respectively. Many phenotypic correlations related to size were high and positive, while weak correlations were found between morphology and reproductive traits. Introducing a queen’s traits in a selection program could improve colonies’ survivability. Further research should focus on better defining the correlations between the individual qualities of a queen and her colony’s performance.

Distinct gene expression dynamics in germ line and somatic tissue during ovariole morphogenesis in Drosophila melanogaster.

The survival and evolution of a species is a function of the number of offspring it can produce. In insects, the number of eggs that an ovary can produce is a major determinant of reproductive capacity. Insect ovaries are made up of tubular egg-producing subunits called ovarioles, whose number largely determines the number of eggs that can be potentially laid. Ovariole number in Drosophila is directly determined by the number of cellular structures called terminal filaments, which are stacks of cells that assemble in the larval ovary. Elucidating the developmental and regulatory mechanisms of terminal filament formation is thus key to understanding the regulation of insect reproduction through ovariole number regulation. We systematically measured mRNA expression of all cells in the larval ovary at the beginning, middle, and end of terminal filament formation. We also separated somatic and germ line cells during these stages and assessed their tissue-specific gene expression during larval ovary development. We found that the number of differentially expressed somatic genes is highest during the late stages of terminal filament formation and includes many signaling pathways that govern ovary development. We also show that germ line tissue, in contrast, shows greater differential expression during early stages of terminal filament formation, and highly expressed germ line genes at these stages largely control cell division and DNA repair. We provide a tissue-specific and temporal transcriptomic dataset of gene expression in the developing larval ovary as a resource to study insect reproduction.

Repeated loss of variation in insect ovary morphology highlights the role of development in life-history evolution.

The number of offspring an organism can produce is a key component of its evolutionary fitness and life history. Here we perform a test of the hypothesized trade-off between the number and size of offspring using thousands of descriptions of the number of egg-producing compartments in the insect ovary (ovarioles), a common proxy for potential offspring number in insects. We find evidence of a negative relationship between egg size and ovariole number when accounting for adult body size. However, in contrast to prior claims, we note that this relationship is not generalizable across all insect clades, and we highlight several factors that may have contributed to this size-number trade-off being stated as a general rule in previous studies. We reconstruct the evolution of the arrangement of cells that contribute nutrients and patterning information during oogenesis (nurse cells), and show that the diversification of ovariole number and egg size have both been largely independent of their presence or position within the ovariole. Instead, we show that ovariole number evolution has been shaped by a series of transitions between variable and invariant states, with multiple independent lineages evolving to have almost no variation in ovariole number. We highlight the implications of these invariant lineages on our understanding of the specification of ovariole number during development, as well as the importance of considering developmental processes in theories of life-history evolution.

Honeybee workers with higher reproductive potential have a greater learning ability

Learning ability, which allows individuals to adjust their behaviour to changing environmental conditions, has a considerable positive impact on individual fitness. However, in addition to benefits, learning also incurs a cost, which means that investment in learning and maintaining learned skills can lead to trade-offs impacting other biological functions. Here, we tested whether a trade-off exists between learning skills and reproductive potential in honeybee workers. For this purpose, we compared learning ability between two groups of workers that differed in reproductive potential—normal and rebel workers. The results showed that workers with high reproductive potential (rebels), measured according to the number of ovarioles in the ovary, learned faster than normal workers with low reproductive potential. Moreover, by performing separate regression analyses within the rebel and non-rebel worker groups, we found that the reproductive potential of workers was positively correlated with their learning ability. The results show that in honeybees, there is no trade-off in resource allocation between two costly biological functions, learning and reproduction.

Effects of three host pine species on diapause induction and life-history traits of Monochamus alternatus alternatus (Coleoptera: Cerambycidae)

ABSTRACT Monochamus alternatus alternatus Hope is distributed in China and Taiwan and transmits the pinewood nematode, the causative agent of pine wilt disease. Unlike univoltine and semivoltine Monochamus alternatus endai Makihara native to Japan, M. a. alternatus has two generations a year (bivoltinism). Some polyphagous insect herbivores exhibit that the incidence of diapause is affected by the host plant species on which they feed, resulting in a host plant dependent variation in the number of generations a year (voltinism). For evaluating the effects of alien pine species on the colonization of M. a. alternatus, its larvae were reared on bolts of Pinus densiflora and P. thunbergii native to Japan and P. echinata native to North America in the laboratory. This study indicated that the three pine species did not increase the incidence of larval diapause to 1.0, suggesting that any pine species did not change the voltinsim. It also determined that the pine species did not influence the ovariole number of females that forwent diapause. The impact of feeding on P. densiflora and P. thunbergii on adult body mass was variable and there was no difference in adult body mass between P. densiflora and P. echinata. Thus, this study suggested that the voltinism of M. a. alternatus was not altered by some pine species native to unoccupied regions such as Japan and North America, i.e. its reproductive rate per year did not decrease owing to reduced number of generations per year, when it arrived there and then colonized.

Dopamine production in the brain is associated with caste-specific morphology and behavior in an artificial intermediate honey bee caste.

Caste polymorphism in eusocial insects is based on morphological plasticity and linked to physiological and behavioral characteristics. To test the possibility that dopamine production in the brain is associated with the caste-specific morphology and behavior in female honey bees, an intermediate caste was produced via artificial rearing using different amounts of diet, before quantifying the dopamine levels and conducting behavioral tests. In field colonies, individual traits such as mandibular shape, number of ovarioles, diameter of spermatheca, and dopamine levels in the brain differed significantly between workers and queens. Females given 1.5 times the amount of artificial diet that control worker receives during the larval stage in the laboratory had characteristics intermediate between castes. The dopamine levels in the brain were positively correlated with the mandibular shape indexes, number of ovarioles, and spermatheca diameter among artificially reared females. The dopamine levels were significantly higher in females with mandibular notches than those without. In fighting experiments with the intermediate caste females, the winners had significantly higher dopamine levels in the brain than the losers. Brain levels of tyrosine were positively correlated with those of catecholamines but not phenolamines, thereby suggesting a strong metabolic relationship between tyrosine and dopamine. Thus, the caste-specific characteristics of the honey bee are potentially continuous in the same manner as those in primitively eusocial species. Dopamine production in the brain is associated with the continuous caste-specific morphology, as well as being linked to the amount of tyrosine taken from food, and it supports the aggressive behavior of queen-type females.

Effects of rearing method on some morphological and reproductive organ characteristics of queen honey bees (Apis mellifera L.)

This study aimed to investigate some of the morphological and reproductive characteristics of the queen honey bees rearing from emergency queen cells and larvae grafting method. The weight at the emergence of queens reared from one-day larvae was found to be higher than other groups (P <0.05). Morphological characteristics of queens according to rearing method showed significant differences of head width, forewing length and forewing width (P <0.05), whereas other morphological characteristics were found similar in different queen groups. No significant difference was observed between the groups in terms of cell length and width (P > 0.05). Wet ovary weights of the queens were weighed at 45, 51, and 49 mg rearing from emergency cells, 1-day-old and 2-day-old larvae, respectively. The number of ovarioles and spermatheca diameter of queens were found to be 268 and 1.14 mm, 296 and 1.21 mm, 285, and 1.16 mm rearing from emergency cells, 1-day-old and 2-day-old larvae, respectively (P <0.05). Consequently, the morphological and reproductive characteristics of queens reared from one-day-old larvae have higher values. According to the results of the study, although some morphological and reproductive features of local queens have low values, their importance should not be ignored in the sustainable future of beekeeping.

Wolbachia increase germ cell mitosis to enhance the fecundity of Laodelphax striatellus

Wolbachia are intracellular bacteria that infect a wide range of invertebrates and have evolved various strategies to alter host reproduction for their own survival and dissemination. In small brown planthopper Laodelphax striatellus, Wolbachia-infected females lay more eggs than uninfected females. Our previous study has shown that Wolbachia are abundant in ovarian cells of L. striatellus and change the number of apoptotic nurse cells in a caspase-dependent manner to provide nutrition for oogenesis. The cellular and molecular bases of the Wolbachia-mediated alterations in L. striatellus oogenesis remain largely unknown. Here, we investigated whether germ cell mitosis, which has been implicated in determination of egg production rates, influences the interaction between fecundity and Wolbachia in L.striatellus. We used an anti-phospho-histone 3 (pH3) antibody to label and visualize mitotic cells. Microscopic observations indicated that the Wolbachia strain wStri increased the number of ovarioles that contained mitotic germ cells. The increased fecundity of Wolbachia-infected females was a result of mitosis of germ cells; the frequency of germ cell mitosis was much higher in infected females than in uninfected females. In addition, mitosis inhibition by Cdc20, CDK1, and CycB messenger RNA interference in Wolbachia-infected L. striatellus markedly decreased egg numbers. Live Wolbachia recolonization enhanced the egg production of uninfected L. striatellus by directly affecting mitosis regulators. Together, these data suggest that wStri might increase germ cell mitosis to enhance the fecundity of L. striatellus in a mitosis-regulating manner. Our findings establish a link between Wolbachia-induced mitosis and Wolbachia-mediated egg production effects.

Topology-driven protein-protein interaction network analysis detects genetic sub-networks regulating reproductive capacity.

Understanding the genetic regulation of organ structure is a fundamental problem in developmental biology. Here, we use egg-producing structures of insect ovaries, called ovarioles, to deduce systems-level gene regulatory relationships from quantitative functional genetic analysis. We previously showed that Hippo signalling, a conserved regulator of animal organ size, regulates ovariole number in Drosophila melanogaster. To comprehensively determine how Hippo signalling interacts with other pathways in this regulation, we screened all known signalling pathway genes, and identified Hpo-dependent and Hpo-independent signalling requirements. Network analysis of known protein-protein interactions among screen results identified independent gene regulatory sub-networks regulating one or both of ovariole number and egg laying. These sub-networks predict involvement of previously uncharacterised genes with higher accuracy than the original candidate screen. This shows that network analysis combining functional genetic and large-scale interaction data can predict function of novel genes regulating development.

Tyramine and its receptor TYR1 linked behavior QTL to reproductive physiology in honey bee workers (Apis mellifera)

Honey bees (Apis mellifera) provide an excellent model for studying how complex social behavior evolves and is regulated. Social behavioral traits such as the division of labor have been mapped to specific genomic regions in quantitative trait locus (QTL) studies. However, relating genomic mapping to gene function and regulatory mechanism remains a big challenge for geneticists. In honey bee workers, division of labor is known to be regulated by reproductive physiology, but the genetic basis of this regulation remains unknown. In this case, QTL studies have identified tyramine receptor 1 (TYR1) as a candidate gene in region pln2, which is associated with multiple worker social traits and reproductive anatomy. Tyramine (TA), a neurotransmitter, regulates physiology and behavior in diverse insect species including honey bees. Here, we examine directly the effects of TYR1 and TA on worker reproductive physiology, including ovariole number, ovary function and the production of vitellogenin (VG, an egg yolk precursor). First, we used a pharmacology approach to demonstrate that TA affects ovariole number during worker larval development and increases ovary maturation during the adult stage. Second, we used a gene knockdown approach to show that TYR1 regulates vg transcription in adult workers. Finally, we estimated correlations in gene expression and propose that TYR1 may regulate vg transcription by coordinating hormonal and nutritional signals. Taken together, our results suggest TYR1 and TA play important roles in regulating worker reproductive physiology, which in turn regulates social behavior. Our study exemplifies a successful forward-genetic strategy going from QTL mapping to gene function.

The influence of developmental diet on reproduction and metabolism in Drosophila

BackgroundThe adaptive significance of phenotypic changes elicited by environmental conditions experienced early in life has long attracted attention in evolutionary biology. In this study, we used Drosophila melanogaster to test whether the developmental diet produces phenotypes better adapted to cope with similar nutritional conditions later in life. To discriminate among competing hypotheses on the underlying nature of developmental plasticity, we employed a full factorial design with several developmental and adult diets. Specifically, we examined the effects of early- and late-life diets (by varying their yeast and sugar contents) on reproductive fitness and on the amount of energy reserves (fat and glycogen) in two wild-caught populations.ResultsWe found that individuals that had developed on either low-yeast or high-sugar diet showed decreased reproductive performance regardless of their adult nutritional environment. The lower reproductive fitness might be caused by smaller body size and reduced ovariole number. Overall, these results are consistent with the silver spoon concept, which posits that development in a suboptimal environment negatively affects fitness-associated traits. On the other hand, the higher amount of energy reserves (fat) in individuals that had developed in a suboptimal environment might represent either an adaptive response or a side-effect of compensatory feeding.ConclusionOur findings suggest that the observed differences in the adult physiology induced by early-life diet likely result from inevitable and general effects of nutrition on the development of reproductive and metabolic organs, rather than from adaptive mechanisms.

Methionine as a methyl donor regulates caste differentiation in the European honey bee (Apis mellifera).

Nutrition contributes to honey bee caste differentiation, but the role of individual nutrients is still unclear. Most essential amino acid contents, except that of methionine (Met), are greater in royal jelly than worker jelly. After ∼3.5 d, the Met content in the latter was slightly greater than in the former. Met is the major raw material used in the synthesis of S-adenosyl-L-methionine, an active methyl donor for DNA methylation, which is an epigenetic driver of caste differentiation. Here, we tested whether Met regulates caste differentiation in honey bees by determining its effects on the caste development of bees receiving four diets: the basic, basic + 0.2% Met, basic + 0.2% Met + 20 mg/kg 5-azacytidine, and basic + 20 mg/kg 5-azacytidine. The presence of Met decreased the adult bee body length and the numbers of ovarioles, indicating that Met may direct the development of female larvae toward worker bees. The upregulated expression of SAMS, Dnmt1, and Dnmt3 caused by Met exposure in 4-d-old larvae indicated that the worker-inductive effects of Met may occur through the promotion of DNA methylation. We investigated the co-effects of Met and glucose on bee development, and found that the effects of an increased glucose level on the number of ovarioles and body length did not strengthen the worker-inductive effects caused by Met. Our results contribute to caste development theory and suggest that Met-as a methyl donor-plays a regulatory, but not decisive, role in caste differentiation.

Direct and indirect effect of cannibalism and intraguild predation in the two sibling Harmonia ladybird beetles.

In this study, we focused on the direct (i.e., predation) and indirect (i.e., potential threat from coexisting with a larger individual) effects of cannibalism and intraguild predation (IGP) during larval stages of two sibling ladybird beetles. These effects play an important role in the coexistence of the generalist–common Harmonia axyridis and specialist–rare H. yedoensis (Coleoptera: Coccinellidae). Direct predation effect of cannibalism and IGP was asymmetric in the two sibling ladybird beetles; the fourth instar larvae of H. axyridis were better intraguild predators than cannibals, while the reverse was true in the larvae of H. yedoensis. Neither cannibalism nor IGP significantly affected female body weight in either species. Larval H. axyridis surviving exposure to cannibalism or IGP had a reduced number of ovarioles as adults, whereas adult H. yedoensis ovarioles were not affected. For the indirect effects, longer developmental times in males and females and a lower total number of ovarioles in females were detected in H. axyridis. In H. yedoensis, shorter developmental time of males, lighter adult weight and fewer total ovarioles in females were observed. Olfactometer choice experiments clarified that the fourth instar larvae of H. axyridis avoided the first instar conspecific larvae, while those of H. yedoensis were attracted to the odors from H. axyridis and conspecifics. Thus, H. axyridis has an avoidance mechanism only for cannibalism but not for IGP, whereas H. yedoensis does not have any avoidance mechanism. These different behaviors in the direct and indirect effects of cannibalism and IGP observed in the laboratory may play important roles in the coexistence of generalist–common H. axyridis and specialist–rare H. yedoensis in natural conditions, compensating for the large handicap of H. yedoensis at reproductive interference from H. axyridis.

Yearly changes in dispersal and life‐history traits of Monochamus alternatus Hope with reference to its outbreak

AbstractThe Japanese pine sawyer, Monochamus alternatus Hope, is the primary vector of the pinewood nematode, Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle, the causative agent of pine wilt disease in East Asia. The range of B. xylophilus expands through the dispersal capability of its vectors and transport of host trees infested with the pathogenic nematode and its vector. Outbreaks of M. alternatus populations occur together with the epidemics of pine wilt disease, because the insect reproduces on host trees recently killed by the disease. We measured some dispersal and life‐history traits of adults for four years to determine the change in flight capability and life history of a field population of beetles in relation to an outbreak. The population monitored exhibited an outbreak and subsequent collapse. The greatest mean body mass, largest area of hind wings, smallest wing load, and shortest preoviposition period were observed in the year of outbreak. By contrast, there was no difference in the ovariole number between pre‐outbreak (latent) and outbreak years. The greatest mean hind wing area and smallest wing load suggest likely result in greater flight performance. As other studies showed, adult body mass is related positively to the flight performance and oviposition rate. Moreover, a shortened preoviposition period leads to a high reproduction rate. Thus, adults in outbreak populations are “superdispersers” because they are likely to have enhanced flight capability and reproduction power. This suggests that M. alternatus populations at the onset of a population outbreak enhance the expansion rate of B. xylophilus range more than those during the latent and pre‐outbreak periods.

Morphometry of the reproductive system of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera, Pentatomidae) when submitted to different temperatures

ABSTRACT: In order to manipulate the mass rearing of natural enemies, temperature variations can be used. The effects are widely studied for their survival and developmental duration; however, there is little information about their reproductive system in the literature. Therefore, the purpose of this study was to evaluate the effects of different temperatures on the reproductive system of the predator Podisus nigrispinus (Dallas, 1851) (Hemiptera: Pentatomidae). The predator was kept at temperature conditions of 17, 21, 25, and 29 °C until reaching 15 days of age, the adult stage. The insects were then killed, measured for both weight and size, dissected, and then evaluated for the following parameters: length of the most developed ovariole; number of ovarioles per ovary; number of oocytes per the more developed ovarioles; number of oocytes per P. nigrispinus female; and the total area of the testicles was measured in the male insects. Results showed that as the temperature increased, the parameters were positively affected. These temperature variations can be used to manipulate the mass rearing of P. nigrispinus under controlled conditions.

Comparing classical and geometric morphometric methods to discriminate between the South African honey bee subspecies Apis mellifera scutellata and Apis mellifera capensis (Hymenoptera: Apidae)

There are two endemic subspecies of western honey bees (Apis mellifera L.) in the Republic of South Africa (RSA), A.m. capensis and A.m. scutellata. They have traditionally been identified using morphometric characteristics, but geometric morphometric data from honey bee wings are easier to collect, possibly making them a useful alternative for identifying these subspecies. We compared the accuracy of both morphometric and geometric morphometric methods using linear discriminant and classification and regression tree analyses. We found that using geometric wing shape data from both forewings and hindwings resulted in a lower classification accuracy (73.7%) than did using models derived from the full set of standard morphometric data (97% accurate) in cross-validation. Tergite color and average ovariole number were the most important features for discriminating between the two subspecies. Finally, we used Kreiger interpolation to construct maps illustrating probable distributions of A.m. capensis and A.m. scutellata in the RSA.

Variation in the number of testicular follicles and ovarioles among 18 lacewing species of the families Myrmeleontidae, Ascalaphidae, and Nemopteridae (Insecta, Neuroptera, Myrmeleontiformia).

The representatives of the lacewing families Myrmeleontidae, Ascalaphidae, and Nemopteridae (the suborder Myrmeleontiformia) were studied with reference to the number of testicular follicles in males and the number of ovarioles in females. We have found that the number of follicles is highly variable, at least in the first two families. In the comparatively more fully explored family Myrmeleontidae, the species studied have three to several hundred follicles per testis, the dominant values being six and five. In Ascalaphidae, two main patterns were revealed: testes with a low number of follicles (six and twelve per testis) and testes with multiple follicles (several dozens). Moreover, differences in the follicle number were often observed both between males of the same species and different testes of a male. In Nemopteridae, considered a sister group to the [Myrmeleontidae + Ascalaphidae] clade, the testes in males were found to consist of six or five follicles each. This implies that a low number of follicles, most likely six, is an ancestral trait in Myrmeleontiformia. All other numbers are thus the derived traits and are probably due to a simple oligomerization or a simple polymerization, the latter process having been very intensive in the evolution of the suborder. Conversely, females were found to have ten ovarioles per ovary in each of the three families studied.