Forewing Length Research Articles

Seasonal polyphenism in body size and juvenile development of the swallowtail butterfly Papilio xuthus (Lepidoptera: Papilionidae)

Seasonal polyphenism in adults may be a season-specific adaptation of the adult stage and/or a by-product of adaptive plasticity of the juvenile stages. The swallowtail butterfly Papilio xuthus L. exhibits seasonal polyphenism controlled by photoperiod. Adults emerging in spring from pupae that spend winter in diapause have smaller bodies than adults emerging in summer from pupae that do not undergo diapause. Pupal diapause is induced by short-day conditions typical of autumn. To explore the interactive effects of temperature and developmental pathways on the variation in adult body size in P. xuthus, we reared larvae at two temperatures (20°C, 25°C) under two photoperiods (12L : 12D and 16L : 8D). Pupal weight and adult forewing length were greater in the generation that did not undergo diapause and were greater at 25°C than at 20°C. Thus, body size differences were greatest between the individuals that were reared at the longer day length and higher temperature and did not undergo diapause and those that were reared at the shorter day length and lower temperature and did undergo diapause. Unlike in other Lepidoptera, larvae of individuals that undergo diapause had shorter developmental times and higher growth rates than those that did not undergo diapause. This developmental plasticity may enable this butterfly to cope with the unpredictable length of the growing season prior to the onset of winter. Our results indicate that there are unexplored variations in the life history strategy of multivoltine Lepidoptera.

Effects of larval crowding and nutrient limitation on male phenotype, reproductive investment and strategy in Ephestia kuehniella Zeller (Insecta: Lepidoptera)

Food shortage experienced by juvenile insects affects adult morphology and life-history traits. Developmental plasticity and trade-off between ecological and sexual traits helps maximise individual fitness. Ephestia kuehniella were reared at different larval densities to investigate phenotypic shifts in adult males. Variation in ecological traits (sizes of forewing, head and thorax and adult longevity) and sexual traits (valva and aedeagus, sperm number, mating frequency) were compared. Males that emerged from highest density population (800) had lower body mass and small forewings, head and thorax, suggesting that they could not completely compensate for food shortage. The allometric relationship between body mass and forewing length also changed, and these males had relatively longer wings. This arrangement may enhance dispersal and assist in mate-searching at higher densities. Males from all larval densities achieved similar mating frequency but those from higher density produced fewer eupyrene sperm and had shorter adult lifespan. By mating more frequently and maintaining apyrene sperm production, males increase their reproductive success at sperm competition observed at higher densities. Food stress associated with high density populations did not affect valva and aedeagus size indicating that these traits may be insensitive to external environmental changes because they incur fitness costs to males.

Morphological characterization and wing description of Vespa orientalis orientalis queens

Oriental hornets, Vespa orientalis, are dangerous enemy to bee colonies in some countries of the world. There are more than one subspecies of V. orientalis. Few studies have investigated the morphological characteristics of these subspecies. Morphological characterization can help in confirming and discriminating between the subspecies, and to follow any changes in their morphology over time. In this study, some body characteristics of V. orientalis orientalis queens from Egypt were measured including head width, fore wing length and width, hind wing length and width, femur length, tibia length and approximate stinger length. Also, fore wing characteristics using wing coordinates for 20 landmarks were studied. Computer based techniques were applied to take these measurements. The data of the current study can be utilized for comparisons with other subspecies.

Assessment of Honey Production Efficiency of Races of Apis mellifera. AdansoniiL. in Nigeria

Variations in the morphometric features of honeybees encountered in this study were within the range for A. mellifera adansonii (below 8mm), while the mean annual honey yield of the races ranged between 9kg in race 1 in the 2010 and 19kg of honey in race 4 in 2008 season. There were significant differences (P<0.05) in honey production among the respective races. Races 3 and 4 produced higher volumes of honey compared with the other races while the lowest volume of honey was recovered from colonies formed by race 1. In addition, positive correlation (P <0.01) was established between honey yield and antenna length (AL, 0.071) (P< 0.05), maximum width of abdomen (MWA, 0.084), proboscis length (PL, 0.078), length of pollen basket (LPB, 0.079), width of pollen basket (WPB, 0.186), length of hind wing (LHW, 0.167), length of Forewing (LFW, 0.164), length offemur (LF, 0.143), length of tarsi (M, 0.229) and length of radial cell of the forewing (LRC,0.109).

Mining bee Andrena (Agandrena) agilissima (Hymenoptera: Andrenidae): A new record from India with morphological and molecular notes

The mining bee Andrena agilissima (Scopoli, 1770), is recorded for the first time in India from the western agro-climatic zone of its Punjab state. This is the first account of morphological and molecular characteristics of A. agilissima. This new record now increases the number of mining bees known in India to 21. Taxonomic commentsand metric values of 40 morphological characters have been presented. The mean values for body length, head width, compound eye length, median ocellus diameter, forewing length and hamuli number were 14.04±0.04 mm, 4.26±0.003 mm, 2.327±0.008 mm, 0.255±0.005 mm, 12.75±0.022 mm and 17.00±0.00, respectively. Using thestandard barcoding protocols, cytochrome c oxidase subunit 1 marker (standard DNA barcode region) based 658 bp DNA barcode sequence of the species has been established, as a first step towards the DNA barcode library of solitary bees of Punjab. The barcode sequence generated for the species has been registered by Gen- Bank, National Centre for Biotechnology Information (NCBI) under accession ‘KT960836’ and Barcode of Life Data (BOLD) Systems under Barcode Index Number ‘BOLD:AAY6909’. The floral sources for A. agilissima in Punjab are also provided. The results can be used to further study the races/ecotypes in different parts of country, habitat management studies, plant-pollinator interactions and in conservation programmes for the species. Further, the precise identification of A. agilissima and the inventory of its foraging plants would provide new opportunities for its potential use as pollinator of crops.

Integrating intraspecific variation in community ecology unifies theories on body size shifts along climatic gradients

Summary Physiological and energetic mechanisms have been proposed to constrain body sizes of organisms along climatic gradients; however, these provide contrasting predictions. While Bergmann's rule predicts increases in body sizes in cooler climates resulting from physiological constraints, energy‐based community assembly rules suggest declines in the mean body size of species caused by increased extinction probabilities for large‐bodied species in low‐energy habitats. We tested these contrasting hypotheses by quantifying trait distributions in bee communities along a 3·6‐km elevational gradient at Mt. Kilimanjaro. Traditionally, intra‐ and interspecific trait shifts along environmental gradients have been investigated in isolation. However, a surge of theoretical approaches and studies on plants demonstrated that the explicit integration of trait variation among and within species can be essential for identifying the mechanisms that shape traits and related ecosystem functions along environmental gradients. We therefore studied variation in body size and related morphological traits at both the intra‐ and interspecific level. We found support for both physiological constraints and energy‐based community assembly rules as drivers of trait distribution in bee communities along elevational gradients, which, however, affected different levels of biotic organization, that is the population and community level. While the number of bee species with large body sizes declined with elevation, individuals within species became on average larger, resulting in contrasting trends in morphometric parameters at the community versus population level. Furthermore, body size within bee communities became less variable at higher elevations, largely as a result of a non‐random, directive loss of species, but paralleled by a decline in intraspecific variance, suggesting intensified filtering effects with increasing elevation. Similar patterns were found for other functional traits related to the foraging ecology of bees (tongue length, relative forewing length). We conclude that along climatic gradients both physiological and energetic constraints shape trait distributions of pollinators, but at different levels of biological organization. A lay summary is available for this article.

The role of environment and core-margin effects on range-wide phenotypic variation in a montane grasshopper.

The integration of genetic information with ecological and phenotypic data constitutes an effective approach to gain insight into the mechanisms determining interpopulation variability and the evolutionary processes underlying local adaptation and incipient speciation. Here, we use the Pyrenean Morales grasshopper (Chorthippus saulcyi moralesi) as study system to (i) analyse the relative role of genetic drift and selection in range-wide patterns of phenotypic differentiation and (ii) identify the potential selective agents (environment, elevation) responsible for variation. We also test the hypothesis that (iii) the development of dispersal-related traits is associated with different parameters related to population persistence/turnover, including habitat suitability stability over the last 120000years, distance to the species distribution core and population genetic variability. Our results indicate that selection shaped phenotypic differentiation across all the studied morphological traits (body size, forewing length and shape). Subsequent analyses revealed that among-population differentiation in forewing length was significantly explained by a temperature gradient, suggesting an adaptive response to thermoregulation or flight performance under contrasting temperature regimes. We found support for our hypothesis predicting a positive association between the distance to the species distribution core and the development of dispersal-related morphology, which suggests an increased dispersal capability in populations located at range edges that, in turn, exhibit lower levels of genetic variability. Overall, our results indicate that range-wide patterns of phenotypic variation are partially explained by adaptation in response to local environmental conditions and differences in habitat persistence between core and peripheral populations.

Biology and management of fruit borer, Virachola isocrates (Fab.) Infesting guava

Two experiments were conducted to study the biology of guava fruit borer, Virachola isocrates (Fab.) and to evaluate the effectiveness of management practices for managing fruit borer, Virachola isocrates (Fab.) in Sharupkathi variety of guava. The biology including morphometrics of guava fruit borer were studied in the laboratory of the Department of Entomology, PSTU, Dumki, Patuakhali during May to October, 2012. Results revealed that incubation period, larval period, pupal period of this borer ranged from 8-10, 17-46, 7-33 days, respectively and total life cycle was completed within 30 to 60 days. Adult longevity ranged from 4-7 days. The average length of full grown larva was 17.45 mm, and breadth across thorax and abdomen were 3.36 and 2.80 mm, respectively. The average length of pupa was 15.90 mm, and breadth across thorax and abdomen were 3.68 and 2.89 mm, respectively. The average length of adult body was 16.90 mm, and breadth across thorax and abdomen were 3.91 and 2.94 mm, respectively. The average length of antennae was 10.35 mm. The mean length of pro-, meso and metathoracic legs was 7.55mm, 8.10mm and 10.45 mm, respectively. The metathoracic leg was longer as compared to pro and mesothorarcic legs. The length of fore wing across the upper and lower margin ranged from 16.00 mm to 18.00 mm and 11.50 mm to 12.00 mm, respectively. The length of hind wing across the upper and lower margin ranged from 10.00 mm to 11.00 mm and 8.00 mm to 9.00 mm, respectively. The breadth of fore wing across the middle ranged from 10.50-11.00 with mean breadth of 10.78 mm. Likewise, the breadth of hind wing across the middle ranged from 11.00-14.00 with mean breadth of 12.55 mm. The results on the percent infestation reduction over control revealed that package with field sanitation + collection of infested fruits + application of Superior (Chlorpyrifos + Cypermethrin) 505 EC @ 1 ml/ l water, and package consisting of field sanitation + collection of infested fruits + bagging of fruits with polythene bag gave 100 % control of the pest. These two packages may be used for the large scale cultivation of ‘Sharupkathi’ variety in BangladeshBangladesh J. Agril. Res. 41(1): 41-51, March 2016

Evaluation of Morphometric Characteristics to Discriminate Inbred Lines of the Honeybee Apis mellifera

As a part of breeding project, five Apis mellifera inbreed lines (named line A, C, D, E and F) were bred and cultivated for several years via an artificial insemination method. In this study, we identified the 5 inbreed lines according to measured morphological values and conducted discriminant analysis. The morphometric characteristics analyzed include basitarsus length (ML), proboscis length (PL), fore wing length (FWL), Rs vein, distance (a), Rs vein, distance (b) and counted the number of hook (Ha). According to the this data, measured means of each body part showed significant differences by one-way ANOVA and post hoc Tukey HSD test (p<0.0001). To evaluate the individuals correctly classified, discriminant analysis was performed using 6 morphometric variables. When all characters were included, the analysis gave 77.4% separation of the individuals to their groups. Among them, line C was assigned 100% and line F was classified 90%, respectively, which determined more accurately classified than other groups. The result shows that the two inbreed lines controlled mating and presence of a more pure population.

Effects of larval dietary restriction on adult morphology, with implications for flight and life history

AbstractMany morphological traits of adult insects show a plastic response to larval environmental conditions. Past studies of Lepidoptera, other than on irruptive species, focused on species with specific ecologies or life histories. These studies must be interpreted in the context of past selection associated with those specializations. Here, we examined the effects on adult morphology of quantitative dietary restriction in the late last instar of Speyeria mormonia Edwards (Lepidoptera: Nymphalidae: Heliconiini). This univoltine species lives in open populations in montane meadows. Adults fed ad libitum as larvae on Viola sororia Willd. (Violaceae) were larger than those fed a restricted diet, for wet and dry body mass, dry mass of head, thorax, or abdomen, and forewing length. Females were larger than males for all but head mass. However, both males and individuals fed a restricted diet had a heavier head and thorax as a proportion of total mass, indicating conservation of visual or other sensory functions and flight. Females maintained a higher relative investment of mass in abdomens, indicating conservation of mass allocation to reproduction. Wing loading was greater in females and for individuals fed ad libitum. The sex*treatment interaction was also significant. The difference in wing loading between individuals fed ad libitum and those on a restricted diet were greater for females than for males. The allometric relationship between dry mass and wing area in both sexes was significantly less than isometric. Thus, allometry did not explain the effect of dietary restriction on wing loading. In contrast, wing aspect ratio was invariant. In combination with earlier studies, these results suggest that mass allocation in support of flight occurs generally under larval nutritional stress. Flight supports both reproduction and feeding. Our work thus highlights the need to include resource acquisition in studies of life history and fitness under nutritional stress.

Influence of the presence of Cacoxenus indagator Loew. parasite larvae in brood chambers on the emergence rate and size of red mason bees

Cacoxenus indagator is one of cleptoparasites most frequently found in the nests of Osmia bicornis L. The goal of this experiment was to examine the influence of the presence of 2-3 C. indagator larvae in the brood chamber on the cocoon mass, on the mass and size of bee imagines, and on their emergence rate. During the analysis of red mason bee nest material, 200 cocoons were taken from brood chambers, each of them also containing 2-3 larvae of C. indagator (CC). The control group consisted of 200 randomly chosen cocoons from brood chambers with no parasites inside (CFFC). The cocoons and the emerged bees were weighed, and then the size of the bees was determined by the microscope image analysis software Axio Vision Rel. 4.0 coupled with a Stereo Lumar V12 stereoscopic microscope (Carl Zeiss, Germany). This involved measuring the sum of the widths of tergites 3 and 4, the distance between the wings and the forewing length and width. It was found that the presence of 2-3 C. indagator larvae in the brood chamber had no impact on the mortality of bees in cocoons. The research demonstrates that CC cocoons do not have to be removed when collecting cocoons from artificial nests in managed O. bicornis populations, as bees emerging from such cocoons are fully developed.

Occurrence and genetics of black‐eyed migratory locusts, Locusta migratoria (Orthoptera: Acrididae)

AbstractBlack‐eyed Locusta migratoria appeared in albino locusts as a result of crossing between a short‐winged strain originating from Tsushima Island, Japan, and an albino strain originating from Okinawa Island. The black eye trait was recessive to the white eye trait because the crosses between black‐ and white‐eyed albino locusts produced only individuals with white eyes in the F1 generation. In the F2 generation, black‐ and white‐eyed individuals appeared in a ratio of 1:3, indicating that the black eye trait was controlled by a simple Mendelian unit. The black eye trait showed no genetic association with other traits including wing morph, adult body dimensions and classical morphometric ratios such as hind femur length / head width and forewing length / hind femur length.

Perch Selection by Three Cooccurring Species ofCelithemis(Odonata: Libellulidae): Testing for a Competitive Hierarchy among Similar Species

In many communities of perching dragonflies (Odonata: Libellulidae), a size-dependent competitive hierarchy creates a positive relationship between male body size and perch height. We tested for this pattern among three similar-sized species:Celithemis elisa,C. fasciata, andC. ornata.Males were caught and photographed from May to July 2015 at Ashmore Heritage Preserve, Greenville County, SC, USA, and perch heights and perch distance to open water were measured. Five indices of body size were measured with ImageJ software: abdomen length, forewing length, hindwing length, area of forewing, and area of hindwing.Celithemis fasciatawas significantly larger than the other two species for all five anatomical characters and used perches that were significantly taller and closer to open water than the other species, though these differences changed over the summer. Aggressive interactions between and within species were tallied and compared to expected distributions based on mean relative abundances derived from hourly abundance counts. Patterns of interspecific aggression were also consistent with a size-dependent hierarchy: the largeC. fasciatawas attacked less frequently, and the smallC. ornatamore frequently, than predicted by their relative abundances. We conclude that even small differences in body size may contribute to niche partitioning in perch selection.

Quantifying interspecific variation in dispersal ability of noctuid moths using an advanced tethered flight technique

Dispersal plays a crucial role in many aspects of species' life histories, yet is often difficult to measure directly. This is particularly true for many insects, especially nocturnal species (e.g. moths) that cannot be easily observed under natural field conditions. Consequently, over the past five decades, laboratory tethered flight techniques have been developed as a means of measuring insect flight duration and speed. However, these previous designs have tended to focus on single species (typically migrant pests), and here we describe an improved apparatus that allows the study of flight ability in a wide range of insect body sizes and types. Obtaining dispersal information from a range of species is crucial for understanding insect population dynamics and range shifts. Our new laboratory tethered flight apparatus automatically records flight duration, speed, and distance of individual insects. The rotational tethered flight mill has very low friction and the arm to which flying insects are attached is extremely lightweight while remaining rigid and strong, permitting both small and large insects to be studied. The apparatus is compact and thus allows many individuals to be studied simultaneously under controlled laboratory conditions. We demonstrate the performance of the apparatus by using the mills to assess the flight capability of 24 species of British noctuid moths, ranging in size from 12-27mm forewing length (~40-660mg body mass). We validate the new technique by comparing our tethered flight data with existing information on dispersal ability of noctuids from the published literature and expert opinion. Values for tethered flight variables were in agreement with existing knowledge of dispersal ability in these species, supporting the use of this method to quantify dispersal in insects. Importantly, this new technology opens up the potential to investigate genetic and environmental factors affecting insect dispersal among a wide range of species.

Trends Observed in Fall Migrant Monarch Butterflies (Lepidoptera: Nymphalidae) East of the Appalachian Mountains at an Inland Stopover in Southern Pennsylvania over an Eighteen Year Period

In total, 11,333 fall migrant monarch butterflies were captured, measured, tagged, and released in southern Pennsylvania over an 18-yr period from 1992 to 2009, excluding 1996 and 2004. Fifty-six (0.494%) were recovered at the Mexican overwintering sites. Hind wing tags had a much higher recovery rate (1.13%) than forewing tags (0.138%). When compared with published recovery rates east of the Appalachians using the same tag type, Pennsylvania was higher than all coastal sites but similar to that of inland Virginia, indicating that inland migrants are more successful. Six U.S. recoveries indicate that monarchs experience considerable eastward wind displacement after leaving the tagging sites. The wild monarchs were divided into three groups for analysis: early (20 Aug–9 Sep), middle (10 Sep–1 Oct), and late (2 Oct–20 Oct) to determine temporal trends. The average forewing length decreased over time, while the percentage of female migrants increased. These trends were not seen in a comparison set of raised monarchs originating from the same general area. As over half the Mexican recoveries came from storm-killed fall 2003 migrants, recoveries were analyzed with and without 2003, and for 2003 alone. More early than middle migrants and no late migrants were recovered. Female migrants were more likely to be recovered from 2003 and overall, but not when 2003 was excluded. The recovery data suggest that males are less likely to make it to Mexico and suffer higher mortality once there during normal overwintering seasons. It also suggests that while early migration is beneficial to both genders, it is even more beneficial for females.

Body Size Variation ofDiaphorina citri(Hemiptera: Psyllidae) Through an Elevation Gradient

ABSTRACT The Asian citrus psyllid, Diaphorina citri Kuwayama, vectors the bacterium ‘Candidatus Liberibacter asiaticus’ responsible for the huanglongbing (HLB) disease. In Mexico, economic losses caused by HLB severely affect the citrus industry. Despite the threat that the presence of D. citri implies, due to its invasive characteristics, there are few ecological and biological studies addressing its adaptation to new and different environments in Mexico. Based on the temperature-size rule, stating smaller adult size at higher rearing temperatures, the aim of this study was to evaluate D. citri's body size variation at different temperatures related to an elevation gradient. Adults were collected at four different elevations in the states of Jalisco and Colima, Mexico. Right forewing length and width as well as prothorax width and right antenna length were measured. Statistical differences between the sexes were analyzed by a multivariate analysis using Hotelling's T2 and Kruskal—Wallis nonparametric tes...

Morphometric comparisons of Diaphorina citri (Hemiptera: Liviidae) populations from Iran, USA and Pakistan.

The Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae), vector of citrus greening disease pathogen, Huanglongbing (HLB), is considered the most serious pest of citrus in the world. Prior molecular based studies have hypothesized a link between the D. citri in Iran and the USA (Florida). The purpose of this study was to collect morphometric data from D. citri populations from Iran (mtCOI haplotype-1), Florida (mtCOI haplotype-1), and Pakistan (mtCOI haplotype-6), to determine whether different mtCOI haplotypes have a relationship to a specific morphometric variation. 240 samples from 6 ACP populations (Iran—Jiroft, Chabahar; Florida—Ft. Pierce, Palm Beach Gardens, Port St. Lucie; and Pakistan—Punjab) were collected for comparison. Measurements of 20 morphological characters were selected, measured and analysed using ANOVA and MANOVA. The results indicate differences among the 6 ACP populations (Wilks’ lambda = 0.0376, F = 7.29, P < 0.0001). The body length (BL), circumanal ring length (CL), antenna length (AL), forewing length (WL) and Rs vein length of forewing (RL) were the most important characters separating the populations. The cluster analysis showed that the Iran and Florida populations are distinct from each other but separate from the Pakistan population. Thus, three subgroups can be morphologically discriminated within D. citri species in this study, (1) Iran, (2) USA (Florida) and (3) Pakistan population. Morphometric comparisons provided further resolution to the mtCOI haplotypes and distinguished the Florida and Iranian populations.

Differences in Wing Morphometrics ofLymantria dispar(Lepidoptera: Erebidae) Between Populations That Vary in Female Flight Capability

All male gypsy moths, Lymantria dispar L., are capable of strong directed flight, but flight in females varies, increasing from west to east geographically across Eurasia. To better understand how the wings differ between female flight capable and flightless strains, a wing morphometric analysis of 821 gypsy moths from eight geographic strains (three Lymantria dispar dispar L., four Lymantria dispar asiatica Vnukovskij, one Lymantria dispar japonica Motschulsky) was performed. Body mass; length and width of both fore- and hindwing; and wing area, aspect, and loads were measured on both sexes from each strain. Gypsy moths were sexually dimorphic; females had a higher wing load, larger aspect ratios, bigger wing area, and heavier body mass than males. Wing loads of females, but not males, differed significantly among geographic strains and were lower in flight capable strains. Wing aspect was less variable within each sex among the strains. Female fore- and hindwing area were both larger in strains with strong directed flight capabilities compared with flightless strains, suggesting both fore- and hindwing areas play significant roles in flight. A logistic regression model using female forewing length and wing load correctly predicted the female flight capability of the source strains >97% of the time and may be a useful tool to use in conjunction with molecular methods for detecting introductions of Asian gypsy moth. None of the male morphometric wing characters were found to reliably predict the female flight capability of the source population.

Multivariate indices as estimates of dry body weight for comparative study of body size in Lepidoptera

Comparative studies on the size of adult Lepidoptera (moths and butterflies) frequently rely on single linear estimates of body size, namely of forewing length or wingspan. As the shape of the wings of these insects - in fact, of all body parts - differs from one taxon to another, such estimates of body mass may not be adequate for comparisons across a wide taxonomic range. Using the length and width of the forewing, thorax and abdomen, as well as the wing area of 375 species and their correlations with dry body weight, several composite indices were determined that might be used in different circumstances. As the coefficients of determination from the multivariate regression models were rather high (R 2 >0.96), the results are believed to be reliable. A critical re-evaluation of the results indicates that important varia- tions in the regression slopes described here would be expected, if at all, only from species with unusual body shapes. Incidentally, the bivariate relationships are in agreement with former comparative work on Lepidoptera and other terrestrial insects in that the relationship between body weight and single linear measurements follows a slightly negatively allometric trend, implying comparatively lighter bodies at the largest body sizes and relatively heavier ones at the shortest body sizes.

Fecundity of the pine processionary moth Thaumetopoea pityocampa (Lepidoptera: Notodontidae) at the southern edge of its distribution range

AbstractAnalysis of annual and plot variations of egg batches number of Thaumetopoea pityocampa at the southern limit of its distribution area and in Pinus halepensis afforestations situated in the Algerian sub-Saharan region showed that its fecundity depends on the density of its population, plots, years and interaction of plots-years. It appears that the high average abundance of egg batches/trees during the outbreak period of this pest insect exceeds 24. The real fecundity is the lowest in the Mediterranean Basin and suggests that local adaptation can occur. The low fecundity is not an obstacle to caterpillar survival under different selection pressures. It is compensated by merging of colonies during the larval cycle. Moreover, in this study we noted a significant correlation between the number of eggs and the size of egg batches deposited on needles or around small pine branches. Size of egg batches is also intimately linked to the length of adult female forewings, fresh weight of females and weight of their pupae. Females with a biennial cycle have a low potential fecundity compared to those with an annual one.