ORGANISM BREEDING: LIVESTOCK AND PROGENY

A captive breeding population of Atala butterflies was maintained under controlled laboratory conditions in Gainesville, Florida, USA (29° 39′ 05″ N, 82° 19′ 29″ W). Comparisons were made with wild colonies previously studied in situ by the first author. Atala larvae and pupae were collected, in development stages ranging from neonate larvae to pharate adults (forming adults, not yet eclosed from the pupa), from wild colonies in Southeast Florida according to available stock in those locations. Collection sites varied and were located on publicly inaccessible, sensitive, privately owned properties. Because the Atala is multivoltine, it was possible to collect approximately 200 individuals (larvae and pupae) 4 times during the 15 mo study (800 individuals in total). The study began in Dec 2011 with wild larval stock from Miami-Dade County, and the colony was replenished with wild larval and pupal stock from 3 different sites located in Miami-Dade, Broward, and Palm Beach Counties in May 2012. Additional larval and pupal stock was collected from a single large population in Palm Beach in Jul 2012, and a final collection of larvae and pupae took place at 3 different locations, again in Miami-Dade, Broward, and Palm Beach Counties, in Oct 2012. Neither eggs nor adults were collected at any time.

The captive breeding population was maintained under controlled laboratory setting with ambient temperature ranging from 24 to 26 °C and relative humidity ranging from 25 to 42%, depending on seasonal weather variation recorded by a Lascar EL-USB-2 data logger (Lascar Electronics, Inc., Erie, Pennsylvania, USA). Insects were kept in a photoperiod of approximately 8:16 h L:D that varied occasionally to 10:14 h L:D. Daylight lamps were programmed for 1:2 h on-to-off increments during the regular day period, and a fan was installed to carry plant and insect chemical signaling volatiles to improve mating and ovipositing activity.

Larvae were fed Z. integrifolia leaves ad libitum harvested from mature landscape plants located on the campus of the University of Florida (Gainesville, Florida, USA), free of pesticides, or from potted nursery stock maintained in a large outdoor screen house or small glass greenhouse, depending on seasonal weather conditions and the availability of plant growth. Fresh leaf material was cut bi-weekly, and the stems of the individual leaves were stored in deionized water. Fronds were then placed into a floral aquapic (Aquapic, Syndicate Sales, Kokomo, Indiana, USA) to ensure that fresh leaf material was presented to the larvae for consumption.

Larvae were maintained in open plastic containers measuring approximately 25 × 50 × 10 cm until they entered into the wandering stage, wherein the larvae begin searching for a pupation site, at approximately 10 d of age. At that point, the larvae and boxes were maintained in 61 × 61 × 30.5 cm fabric cages (Castle Cage Size JUMBO, LiveMonarch Foundation, Boca Raton, Florida, USA). Larvae are gregarious feeders (Minno et al. 2005) and were maintained with their brood-mates throughout the life cycle until adult eclosion.

Cages were cleaned and fresh Zamia leaves were presented to the larvae every morning. Food was replenished throughout the day if necessary. Plant material was presented to the larvae as appropriate for the larval stage; i.e., fresh new growth was given to neonates and older leaves to older larvae.

Larvae were allowed to complete development and pupate within the screen fabric cages. Pupae were misted periodically with deionized water to help prevent desiccation. Following eclosion, all adult butterflies were transferred to a fabric flight cage of approximately 182 cm2 floor area (Greenhouse Castle Cage, Live Monarch Foundation, Boca Raton, Florida, USA) to facilitate courtship and oviposition. Cut Zamia fronds were suspended from the ceiling in aquapics for oviposition. Four lamps with 160 Watt bulbs were located at one end of the cage programmed to emit extra lighting on a 1:2 h on-to-off cycle during the day.

Adults were provided with deionized water, to avoid possible chemicals in tap water, and with Gatorade® (The Gatorade Company, Chicago, Illinois, USA) in fruit punch, orange, or watermelon-citrus flavors. The fluids were offered ad libitum from inverted centrifuge tube feeders, modified from the design described by Hughes et al. (1993). Water was also continually provided via a length of dental packing cord (TIDI Products, Neena, Wisconsin, USA) inserted into a 20 mL flask partially sealed with laboratory parafilm and filled with deionized water. Feeders were hung from the ceiling in the same manner as the oviposition leaves, as well as installed on a short “table” for easier accessibility from the floor where older adults of both sexes often congregated during the night. In addition, occasional seasonal native flowers (primarily Bidens alba [L.] de Candolle; Asterales: Aseraceae) were provided.

All feeders were replenished daily and cleaned weekly. Cotton balls soaked with deionized water were placed on the ceiling of the fabric cage, and the entire cage was misted twice daily with deionized water from a regular spray bottle. The flight cage was cleaned monthly for disease prevention.

Newly eclosed adults were identified with unique alphanumeric codes using a silver metallic Sharpie® brand permanent paint marker (Newell Rubbermaid Office Products, Oak Brook, Illinois, USA) on both ventral hindwings to allow immediate recognition of individuals. Biological data recorded included sex, dates of ovipositing, larval eclosure, pupal emergence, and day of death. Observed matings, number of ovipositions, and associated behaviors were documented, as were fecundity and fertility. Samples of wing cord length were measured from the basal sclerite and resilin patch of the left forewing attachment to the thorax in a straight line to the apex of the wing (Fig. 1). Male dorsal forewing colors were recorded. Females did not display strong variations in dorsal wing color, although there was a marked difference in the extent of color present. All individual adults observed in both captive and wild colonies displayed unique variations in the described and species-recognized patterns on the ventral wing surface (Fig. 2).

Because adult females were not isolated from one another, egg clutches were not identified per individual females. The adult Atala shows highly aggregated behavior in wild colonies, and females have been observed simultaneously ovipositing on the same leaflet as others (per. obs.). With only 1 or 2 coontie leaves in the flight cage, the females gathered and oviposited together on the leaves without any observed stress or aggression. This is normal behavior in a site with limited host plant availability (S. K., unpublished data). However, because individuals were marked, it was known in many cases which female laid eggs and which male mated with her. Marking also allowed documentation of the time passed between mating and ovipositing and of mating behaviors.

Fig. 1.

Wing cord length on adult Atala butterflies was measured from the ventral basal sclerite on the left forewing to the apex of the same forewing using a clear metric ruler.

IMMATURE MEASUREMENTS

Eggs were collected from the adult flight cage daily in the afternoon and counted. Eggs were measured with a standard digital microcaliper under a Leica S8APO stereo microscope (Leica Microsystems, Inc., Buffalo Grove, Illinois, USA) while still on the leaf to prevent accidental damage to the egg while measurements were taken.

Larval exuviae were collected and photographed. Measurements of larvae were abandoned soon after recording was started as it was apparent that the size of the larvae did not necessarily correspond to its age and therefore the measurements could not determine age. Weight of larvae was abandoned for the same reasons; however, some measurements and weights were taken for specific parameters and results are discussed below.

Pupal development was categorized from pre-pupal stage to pharate adult. Development time and size were recorded for each life stage, and individuals were followed from egg and first hatch as a larva until time of death. Pupal weights were recorded for variously aged pupae.

ADULT MEASUREMENTS

Adult wing cord length measurement was taken on the left forewing, from the bottom of the basal sclerite and proximal point of resilin where the forewing emerges from the thorax, to the tip of the apex of the forewing in a straight-line measurement to the nearest whole millimeter using a transparent ruler (C-Thru® Ruler Company, Bloomfield, Connecticut, USA). Measurements of newly eclosed 1st generation adults from wild larval stock that pupated upon arrival were measured for comparison with the captive colony.

Fig. 2.

Individual variations in species-recognized ventral wing patterns were distinct in individuals, but not sexually dimorphic. Four examples of newly emerged adults are presented here. (A and B) Females. (C and D) Males. Note the “sprinkled” iridescence on the anal edge of the hindwing of female B and on the entire wing surface of male D. This iridescence was a frequent observation in both sexes. The forelegs, thorax, and head often had varying degrees of iridescent patterns as well.

Five unmated newly emerged females were euthanized immediately after eclosion to document ovarioles and oogenesis and were dissected to determine average number of ovarioles and oocytes present at eclosion. Subsequent oogenesis, chorion development, egg development and production were determined by counting the numbers of mature and immature eggs in the reproductive tract at death (n = 141). The number of eggs remaining in the oviduct was counted at death. In addition to documenting mating behavior, we recorded the age of each individual at mating, the age at which oviposition commenced, the longevity of known mated individuals and unmated individuals, and whether single or multiple matings occurred between individuals.

STATISTICAL ANALYSES

The total number of adults reared and used as breeding stock in the laboratory included over 5,000 individuals. Statistical analysis examined adult longevity; egg size and egg development; adult, larval, and pupal size range; egg, larval, and pupal maturation rates; fertility and fecundity; sex ratio; and brood size and mortality using R version 2.15.3 (2013-03-01) (R Core Team 2013). Analyses were conducted on varying sample sizes pulled from the total laboratory population based on parameters discussed in the text. For example, of 750 individuals measured for wing cord length, only measurements made by the first author and only measurements associated with adults for which there was a complete life history were used in the analysis. Mean values were presented with the standard deviation (SD).

OOGENESIS, OOCYTE DEVELOPMENT, OVIPOSITION, AND EGG PRODUCTION

New information about female reproduction was discovered. Oocytes were fully formed when adult females eclosed from the pupa, and oogenesis was continual throughout the lifespan of the female. Females were capable of initiating oviposition by the 3rd day after emergence, when chorions were fully formed around the oocytes, and laid as few as 1 egg up to a cluster of as many as 50 or more eggs, generally using the side of a fiddlehead or the underside of a newly emerged Zamia leaf. However, we observed in the field that females also would lay eggs on older leaves, adaxial leaf surfaces, stems, and even reproductive cones of the host plant when host plant availability was limited. Occasionally, females in the captive population laid eggs on non-host substrates such as cage walls, and we had observed newly eclosed females using non-host plants in wild colonies twice (the native host plant was located directly underneath in both cases). Eggs laid on non-host substrates were often fertile, and hatched larvae survived to adulthood within normal development parameters whether reared alone or with other larvae, or reared on the native host or experimentally on non-native Zamia vazquezii D. W. Stev., Sabato, A. Moretti & De Luca (Cycadales: Zamiaceae).

Ovipositing occurred on the same day as mating, or within a day afterwards, and occurred before or without mating. The average age of 1st-time female oviposition in the captive colony was 19.36 ± 7.85 d (n = 234) (Table 1).

Eggs were chosen haphazardly for measurement from fronds suspended in the adult flight cage, from 5 different broods over a 2 mo period to assure a robust sample size (n = 600). Eggs ranged in size from 0.75 to 1.25 mm (mean 1.00 ± 0.15 mm) and showed a bimodal distribution, with the modes at 0.99 and 1.11 mm (Fig. 3). We observed a marked visual difference in the size of eggs from individual dissected females, indicating that size variability is an inherent part of their biology (Fig. 4). Egg development time varied greatly, ranging from 4 to 13 d in the captive population, with an average development time per egg of 6.6 d ± 1.1 d (n = 10,582). There was a 36% successful hatch rate from eggs in the captive population (n = 3,809 larvae) (Table 2).

Eggs had a 3-leaved micropyle and highly sculptured chorion surface, typical of Lycaenidae (Fig. 4). We noted that the underside of the egg was smooth and flat and adhered to the leaf surface with proteins exuded by the females' accessory glands. The undersurface was clear, allowing yolk or the embryo to be seen when the egg was removed from the substrate and inverted upside down. Larvae chew through the micropyle area and did not eat the shell, even avoiding it entirely when neonates congregated to scrape the surface of the leaves en masse with their mandibles during the 1st instar; older larvae also avoided eggs by eating around them.

LARVAL AND PRE-PUPAL DEVELOPMENT

Larval development time was highly variable, ranging from 14 to 28 d in the laboratory (n = 1,021). The average development time was 18.4 ± 3.6 d after emergence from the egg (Table 2). Neonate larvae were capable of releasing silk lifelines to aid in locomotion, such as descending from a higher leaflet to another, or to adhere to a leaf.

Larval broods were reared with siblings; individuals were reared alone when they had hatched from only 1 ovum in a clutch. Five newly hatched larvae that were weighed within 2 h of hatching and reared on Z. integrifolia had an average weight of 7.2 ± 0.9 mg, ranging between 0.4 and 2.5 mg. By day 5, they had reached an average weight of 385.3 ± 34.7 mg with a range between 7.6 and 85.8 mg. From day 5 to day 11, larvae increased their weight to 537.4 ± 95.0 mg, ranging between 470.2 and 604.6 mg. Larvae showed marked differences in feeding robustness.

Table 1.

Mean ± SD lifespan (d) and mating and ovipositing ages (d) of individuals after eclosion from the egg.

Fig. 3.

Frequency and mean size of Atala egg distribution (n = 600).

Newly hatched larvae measured between 0.5 and 15 mm, but after the 1st molt it became difficult to standardize a measurement protocol partly because of the high variability in the growth and weight of the larvae regardless of age, and the extreme plasticity of the larval body, so the endeavor was abandoned after the 1st instar (Fig 5A). Larger larvae (1.0–1.5 mm) fed more aggressively and developed more rapidly than the smaller larvae.

Fig. 4.

(A) Visually apparent size differences in eggs from a dissected female. (B) Scanning electron microscopy photograph of an Atala egg showing highly sculptured chorion ultrastructure and micropyle. Bar measures 200 µm.

Table 2.

Atala development time and survival from ovipositing to adult emergence (n = 10,582).

This report is the first record of larval instars in the Atala, which present a 3 d, 5 d, 7 d, 9 d, and sometimes 11 d molt (Fig. 5C). Being variable in almost every stage of development, occasionally there was a 4 d, 6 d, 8 d, or 10 d molt evident in a clutch, likely because the individual was not as robust a feeder, and perhaps started out smaller than the other larvae in the brood and therefore developed more slowly than its cage mates (Fig. 5B). Exuviae were not ingested by larvae in any instar and were avoided in much the same way as were the eggs and egg chorions.

Additionally, although the larvae were fed ad libitum, they often also completely devoured the rachis of their host plants as well as the foliage. Occasionally, the larvae would ingest parts of the silicone caps on the waterpics used to hold the host material, and would cannibalize conspecifics, which dropped the survival rate to as low as 14% in some broods. In several instances, a brood that started with small numbers could be reduced to a single larva by the time it entered the wandering stage if one of the larvae was a particularly aggressive feeder.

The wandering stage of development occurred at approximately day 10 of larval life. By day 12 or 13, most larvae became “pre-pupae” in preparation for the final molt (Fig. 6A and B). Larvae would migrate en masse to the pupation site within the fabric cage, which could be the walls of the shoebox housing or the walls or ceiling of the fabric cage. One or two larvae in the brood would rarely migrate away from cage mates to pupate alone; larvae that were slower in development usually migrated to a pupation site previously established by other larvae.

Pre-pupae formed large areas of silk mats underneath their aggregation, anchoring the cluster to the substrate and to each other (Fig. 5D). Larvae that were under stress from food limitations due to aggressively feeding brood mates, handling (such as being moved from wild stock), larval competition for space, type of food, or other unknown factors were capable of pupating after the 3rd instar, forming exceptionally small pupae (see below). These individuals survived to adulthood and were often successful in mating, particularly the small males (those with wing cord lengths <2.0 cm). The lifespan of these small individuals was not adversely affected by size or sex. The average lifespan of females with wing cord lengths measuring under 2.0 cm was 19.06 ± 12.17 d (n = 32). The average lifespan of males with wing cord lengths measuring under 2.0 cm was 23.03 ± 12.62 d (n = 32), and the average lifespan of individuals with wing cord lengths measuring under 2.0 cm was 21.05 ± 12.64 d (n = 64).

Juvenile mortality was high in the larval stage, and cannibalism was substantial in broods even when continually provided with highquality, green, fresh host material. Cannibalism is common in otherwise herbivorous lepidopteran species (Richardson et al. 2010). There was an increase in survival to pupation in smaller groups, but it was not found to be as significant with Atala as it has been documented in other species, such as Euselasia chrysippe (Bates) (Lepidoptera: Lycaenidae) (Allen 2011). Of 90 broods, the number surviving to the next life stage increased as the life stage progressed from egg to larva to pupa and finally to adult (Table 2 and Fig. 7). The survival rate from larva to pupa in a sample of the captive population was 58% (n = 3,809; Table 2).

PUPAL DEVELOPMENT

Pupal development time was recorded as the time of the final larval molt to eclosion as an adult and ranged from 11 to 19 d (n = 1,021). The average development time was 14.4 ± 2.4 d (Table 2). There was a substantial difference in size and weight of pupae, but the results were similar to individuals from wild colonies, which also had smaller than normal pupae under stress (Fig. 8A). Pupae were weighed as available and whenever time and equipment use permitted.

Pupae were sexed under a dissecting scope. Females had 2 small bulges on the last abdominal section and a pointed apex at the anal opening. On males, the last abdominal section and the anal opening were rounded. Weights of male and female pupae indicated that even though female pupae weighed more than male pupae (Table 3), there was no significant difference in development time (t = 1.3659, df = 48, P = 0.1783).

Pre-pupal stages occurred over several days, beginning between 12 and 14 d of larval development and usually in the 4th instar. In the 1st stage, the larvae “bunched up” in a vermiform position and anchored firmly to the substrate, although they were still capable of re-locating before final stages began. In the 2nd stage, the last larval integument began to separate from the pharate adult forming internally and the skin had a semi-translucent and mottled appearance. The body was firmly anchored to the substrate, the silk girdle was released from the thorax to support the body, and by the 2nd or 3rd day, the larva made the complete transformation to a pupa. The head and caudal region turned a soft yellow color in the newly formed pupae but soon changed to a darker mottled brown. Pupation took place within 1 or 2 d after the pre-pupal stage, indicated by the shedding of the last larval skin with associated mouth parts and exuviae. Subsequent experiments showed that cooler temperatures caused darker pigmentation in the pupa (S. K., unpublished data).

There was 91 to 98% survival from pupa to adult in the laboratory (n = 2,077) (Table 2). Pupal size and weight varied significantly, but there was no correlation between sex and longevity of the resulting adults. Small pupae eclosed as small adults of both sexes, with wing cord lengths ranging from 1.4 to 1.9 cm. Small adults with wing cord lengths measuring less than 2.0 cm of both sexes lived on average as long as adults that had an average wing cord lengths of 2.1 cm or more (n = 32). Small males often successfully mated with larger females.

TOTAL DEVELOPMENT TIME

Total development time from egg to adult ranged from 30 to 57 d (n = 1,261). Average total development time was 39.3 ± 3.7 d. Adults successfully eclosed from 94% of pupae in the captive population (Table 2). Development time for all life stages varied even more widely in environmental chambers programmed for seasonal experiments (S. K., unpublished data).

Fig. 5.

Life stages of Eumaeus atala. (A) Automontage photograph of 2-h-old newly hatched larvae that measured between 0.5 and 1.5 mm in length. (B) Nineday- old larvae from the same brood, and which hatched on the same day, showed high variability in size. The smaller larva successfully pupated 3 d later than its brood mates but developed into a smaller pupa and subsequent adult. (C) Automontage photograph of 5 normal instar exuviae. Stadia were variable, between 2 and 4, with most larvae pupating in the 4th instar. The 1st instar occurred at 3 d. (D) Silk mats may form an extensive anchor to the substrate beneath an aggregation of Atala pupae. Bars measure 1 mm.

ADULT MATING, MEASUREMENTS, AND LONGEVITY

The average age of female mating was 15.45 ± 8.94 d (n = 117) and ranged from newly eclosed to 41 d of age. The average age of male mating was not significantly different (P = 0.38) at 11.98 ± 7.63 d (n = 117) and ranged from newly eclosed to 38 d of age (Table 1). Of those observations, the mean longevity of observed mated females was 32.96 ± 8.83 d (n = 76) and the mean longevity for observed mated males was not significantly different (P = 0.99) at 34.38 ± 11.03 d (n = 76) (Table 1). Average adult wing cord length did not significantly differ between the sexes (t = 1.0765, df = 31, P = 0.2900) (n = 600), but the shortest cord lengths were measured in males and the longest in females. In the captive population, the average wing cord length was 2.2 ± 0.19 cm for females and 2.1 ± 0.15 cm for males. In the captive population, the shortest measured wing cord length was 1.4 cm (male) and the longest was 2.5 cm (female), although one individual female measured 2.7 cm in a controlled seasonal experiment. Although no measurements were taken in wild colonies in prior years, photographs of deceased individuals in both captive and wild colonies placed beside common U.S. coinage allowed a visual comparison to be made (Fig. 8C and D).

Fig. 6.

Development of Atala pupal stages; the head region is on the right. (A) The dorsal surface of the larva begins to disengage from the larval integument, leaving a mottled apprearance. (B) The ventral surface displays extensive webbing, and the head region and caudal end turn yellow by the 2nd day. (C) On the 2nd or 3rd day, the pupa is fully formed. (D) Automontage photograph of a 4-d-old pupa showing silk girdle around the thoracic segment and mat attached to the host plant leaf, with cast-off larval skin at the caudal end of the pupa. It is shown in a head-down position. Bar measures 1 mm.

Measurements were taken of adults that eclosed from wild larval stock collected in May 2012 (Fig. 9). Females in that brood had an average wing length of 2.37 ± 0.13 cm, whereas males had an average wing length of 2.22 ± 0.11 cm. Results from Atala reared in controlled environmental chambers by the first author will be forthcoming and show significant differences between seasonal growth rates and size.

Our observations challenge previously recorded lifespans, as the average lifespan of adults was 23.6 ± 13.4 d (n = 1,021) in the laboratory In addition, an outdoor colony was maintained in a shade house in Gainesville, Florida, USA, for several months, receiving only flowers for nectar and Zamia plants for oviposition and for feeding the larvae (no Gatorade or additional water was provided); individuals in this colony lived on average 14.2 ± 6.2 d (n = 36). One male in the outdoor colony lived 31 d. There was no correlation between smaller adult size (wing cord length <2.0 cm) and longevity, and no statistically significant difference between males and females (t = 1.0765, df = 31, P = 0.2900).

One male with a wing cord length of 1.9 cm lived 53 d, and 1 female with a wing cord length of 1.6 cm lived for 26 d.

Adults often exhibited a strong startle or warning response when first handled (to be marked with identification numbers) by quickly flashing open the ventral forewings to expose the dorsal wing colors (bright blue or blue-green) and raising the bright red-orange abdomen in protest, possibly to advertise its toxic nature via its aposematic colors. Evasive tactics employed by flying adults included dropping suddenly to another level and changing flight direction erratically and unpredictably.

Fig. 7.

Mean proportion of survival of Atala per life stage (n = 10,917 eggs).

Fig. 8.

There was a significant difference in size and weight of pupae not correlated with sex. (A) Pupae from the captive population, approximately 4 d old. (B) Compare with a similar photo of pupae from a wild colony in Fort Lauderdale, Florida, taken in 2006, approximately 2 d old. (C) Photograph of deceased adults from captive populations placed beside common U.S. coinage. (D) Adults from wild stock collected in 2006 from a Broward County site in Florida and placed above common U.S. coinage displayed similar size differences.

ADULT DISSECTIONS AND EGG DEVELOPMENT

Newly emerged females had no developed eggs with chorions, but did possess 4 to 15 fully yolked oocytes, with a mean of 9.6 oocytes (n = 5). Chorions were developed between the 3rd and 7th days even in unmated females, and oogenesis was continual throughout the females' lifetime. Females had 6 ovarioles, and eggs from the same female often varied in size. As many as 51 eggs were dissected from 1 female (15 d old) that was not observed ovipositing prior to death. One 80-d-old female contained no eggs and an 86-d-old female contained 29 eggs. Female continuous egg production and variability was evident at all ages (n = 128; Fig. 10). Egg maturation with chorion also varied between 3 d (1 egg) to 7 d (21 eggs). A 9-d-old female contained 1 ovum, but a 4-d-old contained 24 eggs.

LIFESPAN AND SEX RATIO

Adults in captivity lived an average of 23.6 ± 13.4 d (n = 1,021) (Fig. 11), with a very wide range from immediate death because of eclosion failure (0 days) to a female that lived for 86 d. The oldest male in the captive population (Fig. 12A) survived to 71 d and originated as a late instar from the Miami-Dade County summer stock, perhaps indicating that wild individuals are also capable of a much longer lifespan than previously recorded. For instance, a 1-mo-old Atala was photographed as part of a wild colony observed daily by the first author in 2008 in Broward County (Fig. 12B).

The sex ratio was 1:0.95 (female to male; n = 600). Lifespans were not significantly different between females and males (t = 1.5863, df = 49, P = 0.1191), with females (22.57 ± 11.84 d) living an average of 2 d less than males (25.14 ± 14.86 d).

Table 3.

Weight of Atala pupae by age and sex.

Adult Atala lifespans were not significantly different between small individuals with wing cord lengths measuring less than 2.0 cm and large individuals with wing cord lengths measuring 2.0 cm or more, regardless of sex. Small and large females lived an average of 17.84 ± 12.02 d and 19.13 ± 9.34 d, respectively (t = 0.3356, df = 30, P = 0.7695). Small and large males lived an average of 23.03 ± 12.62 d and 18.03 ± 7.48 d, respectively (t = 1.9022, df = 31, P = 0.0665).

ABNORMALITIES AND PATHOGENS

Less than 1% of individuals presented an eclosion failure, pupation or wing abnormality, or other aberration in the captive population (n = 1,282). In observations of pooled data from wild colonies in Palm Beach, Broward, and Miami-Dade Counties between 2004 and 2005, the first author documented that 4% of the wild populations had wing abnormalities, such as an inability to fully expand wings, and 8% of the population did not successfully eclose (n = 3,430).

Fig. 9.

Graph of wing cord length of emerged adults that were collected as wild late larval stock and that completed final instar in the laboratory, pupating immediately after relocation. Numbers refer to site locations (1 is in Broward County and 2 is located in Miami-Dade County, Florida).

An entomopathogenic Paecilomyces fungus (Eurotiales: Trichocomaceae) was found occasionally in eggs, larvae, and pupae, which likely was contracted from the substrate as larvae crawled from place to place. One experiment with our captive population indicated that the fungus is contagious, but more experimentation would need to be conducted to determine if it has a deleterious effect on wild colonies.